upgrade to new JSON parser

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/analytics/PackageVisitor.java

@@ -16,8 +16,10 @@ import org.hl7.fhir.utilities.SimpleHTTPClient;
 import org.hl7.fhir.utilities.SimpleHTTPClient.HTTPResult;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonElement;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.FilesystemPackageCacheManager;
 import org.hl7.fhir.utilities.npm.NpmPackage;
 import org.hl7.fhir.utilities.npm.PackageClient;
@@ -28,10 +30,6 @@ import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.xml.sax.SAXException;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-
 public class PackageVisitor {
   
   public interface IPackageVisitorProcessor {
@@ -140,11 +138,11 @@ public class PackageVisitor {
       }
       i++;
     }    
-    JsonObject json = JsonTrackingParser.fetchJson("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json");
+    JsonObject json = JsonParser.parseObjectFromUrl("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json");
     i = 0;
-    List<JsonObject> objects = JsonUtilities.objects(json, "guides");
+    List<JsonObject> objects = json.getJsonObjects("guides");
     for (JsonObject o : objects) {
-      String pid = JsonUtilities.str(o, "npm-name");
+      String pid = o.asString("npm-name");
       if (pid != null && !cpidSet.contains(pid)) {
         cpidSet.add(pid);
         List<String> vList = listVersions(pid);
@@ -195,11 +193,10 @@ public class PackageVisitor {
   private Map<String, String> getAllCIPackages() throws IOException {
     Map<String, String> res = new HashMap<>();
     if (current) {
-      JsonArray json = JsonTrackingParser.fetchJsonArray("https://build.fhir.org/ig/qas.json");
+      JsonArray json = (JsonArray) JsonParser.parseFromUrl("https://build.fhir.org/ig/qas.json");
-      for (JsonElement j : json) {
+      for (JsonObject o  : json.asJsonObjects()) {
-        JsonObject o = (JsonObject) j;
+        String url = o.asString("repo");
-        String url = JsonUtilities.str(o, "repo");
+        res.put(url, o.asString("package-id"));
-        res.put(url, JsonUtilities.str(o, "package-id"));
       }
     }
     return res;
@@ -220,13 +217,13 @@ public class PackageVisitor {
     for (PackageInfo i : pc.search(null, null, null, false)) {
       list.add(i.getId());
     }    
-    JsonObject json = JsonTrackingParser.fetchJson("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json");
+    JsonObject json = JsonParser.parseObjectFromUrl("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json");
-    for (JsonObject ig : JsonUtilities.objects(json, "guides")) {
+    for (JsonObject ig : json.getJsonObjects("guides")) {
-      list.add(JsonUtilities.str(ig, "npm-name"));
+      list.add(ig.asString("npm-name"));
     }
-    json = JsonTrackingParser.fetchJson("https://raw.githubusercontent.com/FHIR/ig-registry/master/package-feeds.json");
+    json = JsonParser.parseObjectFromUrl("https://raw.githubusercontent.com/FHIR/ig-registry/master/package-feeds.json");
-    for (JsonObject feed : JsonUtilities.objects(json, "feeds")) {
+    for (JsonObject feed : json.getJsonObjects("feeds")) {
-      processFeed(list, JsonUtilities.str(feed, "url"));
+      processFeed(list, feed.asString("url"));
     }
     
     return list;

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/CorePackageTools.java

@@ -7,10 +7,10 @@ import java.io.IOException;
 
 import org.hl7.fhir.exceptions.FHIRFormatError;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.NpmPackage;
 
-import com.google.gson.JsonObject;
 
 public class CorePackageTools {
 
@@ -33,7 +33,7 @@ public class CorePackageTools {
   private void buildXml(String json, String xml, String version) throws FHIRFormatError, IOException {
     for (File f : new File(Utilities.path(json, "package")).listFiles()) {
       if (f.getName().endsWith(".json")) {
-        JsonObject j = new JsonTrackingParser().parseJson(f);
+        JsonObject j = JsonParser.parseObject(f);
         if (j.has("resourceType")) {
           if ("1.4".equals(version)) {
             String n = f.getName();

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/ExamplesPackageBuilder.java

@@ -10,9 +10,8 @@ import java.util.Set;
 import org.hl7.fhir.convertors.factory.VersionConvertorFactory_40_50;
 import org.hl7.fhir.exceptions.FHIRFormatError;
 import org.hl7.fhir.utilities.TextFile;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
-
+import org.hl7.fhir.utilities.json.parser.JsonParser;
-import com.google.gson.JsonObject;
 
 public class ExamplesPackageBuilder {
 
@@ -25,10 +24,10 @@ public class ExamplesPackageBuilder {
     Set<String> set = new HashSet<>();
     for (File f : new File(source).listFiles()) {
       if (f.getName().endsWith(".json")) {
-        JsonObject obj = JsonTrackingParser.parseJson(new FileInputStream(f));
+        JsonObject obj = JsonParser.parseObject(new FileInputStream(f));
         if (obj.has("resourceType") && obj.has("id")) {
-          String type = obj.get("resourceType").getAsString();
+          String type = obj.asString("resourceType");
-          String id = obj.get("id").getAsString();
+          String id = obj.asString("id");
           byte[] content = TextFile.fileToBytes(f);
           if (type.equals("ConceptMap")) {
             System.out.println("convert "+f.getName());

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/ICD11Generator.java

@@ -28,10 +28,9 @@ import org.hl7.fhir.r4.utils.ToolingExtensions;
 import org.hl7.fhir.utilities.SimpleHTTPClient;
 import org.hl7.fhir.utilities.SimpleHTTPClient.HTTPResult;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonElement;
-
+import org.hl7.fhir.utilities.json.model.JsonObject;
-import com.google.gson.JsonElement;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
-import com.google.gson.JsonObject;
 
 public class ICD11Generator {
 
@@ -42,12 +41,12 @@ public class ICD11Generator {
   private void execute(String base, String dest) throws IOException {
     CodeSystem cs = makeMMSCodeSystem();
     JsonObject version = fetchJson(Utilities.pathURL(base, "/icd/release/11/mms"));
-    String[] p = version.get("latestRelease").getAsString().split("\\/");
+    String[] p = version.asString("latestRelease").split("\\/");
     cs.setVersion(p[6]);
-    JsonObject root = fetchJson(url(base, version.get("latestRelease").getAsString()));
+    JsonObject root = fetchJson(url(base, version.asString("latestRelease")));
-    cs.setDateElement(new DateTimeType(root.get("releaseDate").getAsString()));
+    cs.setDateElement(new DateTimeType(root.asString("releaseDate")));
-    for (JsonElement child : root.getAsJsonArray("child")) {
+    for (JsonElement child : root.getJsonArray("child")) {
-      processMMSEntity(cs, base, child.getAsString(), cs.addConcept(), dest);
+      processMMSEntity(cs, base, child.asString(), cs.addConcept(), dest);
       System.out.println();
     }
     new XmlParser(XmlVersion.V1_1).setOutputStyle(OutputStyle.PRETTY).compose(new FileOutputStream(Utilities.path(dest, "icd-11-mms.xml")), cs);
@@ -55,12 +54,12 @@ public class ICD11Generator {
 
     cs = makeEntityCodeSystem();
     root = fetchJson(Utilities.pathURL(base, "/icd/entity"));
-    cs.setVersion(root.get("releaseId").getAsString());
+    cs.setVersion(root.asString("releaseId"));
-    cs.setDateElement(new DateTimeType(root.get("releaseDate").getAsString()));
+    cs.setDateElement(new DateTimeType(root.asString("releaseDate")));
     cs.setTitle(readString(root, "title"));
     Set<String> ids = new HashSet<>();
-    for (JsonElement child : root.getAsJsonArray("child")) {
+    for (JsonElement child : root.getJsonArray("child")) {
-      processEntity(cs, ids, base, tail(child.getAsString()), dest);
+      processEntity(cs, ids, base, tail(child.asString()), dest);
       System.out.println();
     }
     new XmlParser(XmlVersion.V1_1).setOutputStyle(OutputStyle.PRETTY).compose(new FileOutputStream(Utilities.path(dest, "icd-11-foundation.xml")), cs);
@@ -80,34 +79,34 @@ public class ICD11Generator {
         cc.setDefinition(d);
       }
       if (entity.has("inclusion")) {
-        for (JsonElement child : entity.getAsJsonArray("inclusion")) {
+        for (JsonElement child : entity.getJsonArray("inclusion")) {
           JsonObject co = (JsonObject) child;
           String v = readString(co, "label");
           if (v != null) {
             if (co.has("foundationReference")) {
-              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.get("foundationReference").getAsString())).setDisplay(v)).setCode("inclusion");
+              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.asString("foundationReference"))).setDisplay(v)).setCode("inclusion");
             }
           }
         }
       }
       if (entity.has("exclusion")) {
-        for (JsonElement child : entity.getAsJsonArray("exclusion")) {
+        for (JsonElement child : entity.getJsonArray("exclusion")) {
           JsonObject co = (JsonObject) child;
           String v = readString(co, "label");
           if (v != null) {
             if (co.has("foundationReference")) {
-              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.get("foundationReference").getAsString())).setDisplay(v)).setCode("exclusion");
+              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.asString("foundationReference"))).setDisplay(v)).setCode("exclusion");
             }
           }
         }
       }
       if (entity.has("narrowerTerm")) {
-        for (JsonElement child : entity.getAsJsonArray("narrowerTerm")) {
+        for (JsonElement child : entity.getJsonArray("narrowerTerm")) {
           JsonObject co = (JsonObject) child;
           String v = readString(co, "label");
           if (v != null) {
             if (co.has("narrowerTerm")) {
-              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.get("foundationReference").getAsString())).setDisplay(v)).setCode("narrowerTerm");
+              cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/foundation").setCode(tail(co.asString("foundationReference"))).setDisplay(v)).setCode("narrowerTerm");
             }
           }
         }
@@ -115,22 +114,22 @@ public class ICD11Generator {
       addDesignation(readString(entity, "longDefinition"), cc, "http://id.who.int/icd11/mms/designation", "longDefinition");
       addDesignation(readString(entity, "fullySpecifiedName"), cc, "http://snomed.info/sct", "900000000000003001");
       if (entity.has("synonym")) {
-        for (JsonElement j : entity.getAsJsonArray("synonym")) {
+        for (JsonElement j : entity.getJsonArray("synonym")) {
           String v = readString((JsonObject) j, "label");
           if (v != null && !v.equals(cc.getDisplay())) {
             addDesignation(v, cc, "http://id.who.int/icd11/mms/designation", "synonym");
           }
         }
       }
-      for (JsonElement j : entity.getAsJsonArray("parent")) {
+      for (JsonElement j : entity.getJsonArray("parent")) {
-        String v = j.getAsString();
+        String v = j.asString();
         if (!"http://id.who.int/icd/entity".equals(v)) {
           cc.addProperty().setValue(new CodeType(tail(v))).setCode("narrowerTerm");
         }
       }
       if (entity.has("child")) {
-        for (JsonElement j : entity.getAsJsonArray("child")) {
+        for (JsonElement j : entity.getJsonArray("child")) {
-          String v = j.getAsString();
+          String v = j.asString();
           cc.addProperty().setValue(new CodeType(tail(v))).setCode("child");
           processEntity(cs, ids, base, tail(v), dest);
         }
@@ -180,16 +179,16 @@ public class ICD11Generator {
     System.out.print(".");
     JsonObject entity = fetchJson(url(base, ref));
     cc.setId(tail(ref));
-    if (entity.has("code") && !Utilities.noString(entity.get("code").getAsString())) {
+    if (entity.has("code") && !Utilities.noString(entity.asString("code"))) {
-      cc.setCode(entity.get("code").getAsString());
+      cc.setCode(entity.asString("code"));
-    } else if (entity.has("blockId") && !Utilities.noString(entity.get("blockId").getAsString())) {
+    } else if (entity.has("blockId") && !Utilities.noString(entity.asString("blockId"))) {
-      cc.setCode(entity.get("blockId").getAsString());
+      cc.setCode(entity.asString("blockId"));
     } else {
       cc.setCode(cc.getId());
       cc.addProperty().setCode("abstract").setValue(new BooleanType(true));
     }
-    if (entity.has("classKind") && !Utilities.noString(entity.get("classKind").getAsString()) && !"category".equals(entity.get("classKind").getAsString())) {
+    if (entity.has("classKind") && !Utilities.noString(entity.asString("classKind")) && !"category".equals(entity.asString("classKind"))) {
-      cc.addProperty().setCode("kind").setValue(new CodeType(entity.get("classKind").getAsString()));
+      cc.addProperty().setCode("kind").setValue(new CodeType(entity.asString("classKind")));
     }
     cc.setDisplay(readString(entity, "title"));
     StringBuilder defn = new StringBuilder();
@@ -203,7 +202,7 @@ public class ICD11Generator {
     if (entity.has("inclusion")) {
       defn.append(". Includes: ");
       boolean first = true;
-      for (JsonElement child : entity.getAsJsonArray("inclusion")) {
+      for (JsonElement child : entity.getJsonArray("inclusion")) {
         if (first) first = false;
         else defn.append(", ");
         defn.append(readString((JsonObject) child, "label"));
@@ -212,7 +211,7 @@ public class ICD11Generator {
     if (entity.has("exclusion")) {
       defn.append(". Excludes: ");
       boolean first = true;
-      for (JsonElement child : entity.getAsJsonArray("exclusion")) {
+      for (JsonElement child : entity.getJsonArray("exclusion")) {
         if (first) first = false;
         else defn.append(", ");
         JsonObject co = (JsonObject) child;
@@ -220,7 +219,7 @@ public class ICD11Generator {
         if (v != null) {
           defn.append(v);
           if (co.has("linearizationReference")) {
-            cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/mms").setCode(tail(co.get("linearizationReference").getAsString())).setDisplay(v)).setCode("exclusion");
+            cc.addProperty().setValue(new Coding().setSystem("http://id.who.int/icd11/mms").setCode(tail(co.asString("linearizationReference"))).setDisplay(v)).setCode("exclusion");
           }
         }
       }
@@ -231,33 +230,33 @@ public class ICD11Generator {
     addProperty(readString(entity, "codingNote"), cc, "codingNote");
     if (entity.has("indexTerm")) {
 //      CommaSeparatedStringBuilder b = new CommaSeparatedStringBuilder("; ");
-//      for (JsonElement child : entity.getAsJsonArray("indexTerm")) {
+//      for (JsonElement child : entity.getJsonArray("indexTerm")) {
 //        processIndexTerm(cc, b, (JsonObject) child);    
 //      }
 //      if (b.length() > 0) {
 //        cc.addProperty().setCode("terms").setValue(new StringType(b.toString()));        
 //      }
-      for (JsonElement child : entity.getAsJsonArray("indexTerm")) {
+      for (JsonElement child : entity.getJsonArray("indexTerm")) {
         processIndexTerm(cc, (JsonObject) child);
       }
     }
     if (entity.has("postcoordinationScale")) {
-      for (JsonElement child : entity.getAsJsonArray("postcoordinationScale")) {
+      for (JsonElement child : entity.getJsonArray("postcoordinationScale")) {
         JsonObject o = (JsonObject) child;
-        String name = tail(o.get("axisName").getAsString());
+        String name = tail(o.asString("axisName"));
         ConceptPropertyComponent prop = cc.addProperty();
         prop.setCode("postcoordinationScale");
         prop.setValue(new CodeType(name));
-        ToolingExtensions.addBooleanExtension(prop, "http://id.who.int/icd11/extensions/required", o.get("requiredPostcoordination").getAsBoolean());
+        ToolingExtensions.addBooleanExtension(prop, "http://id.who.int/icd11/extensions/required", o.asBoolean("requiredPostcoordination"));
-        ToolingExtensions.addBooleanExtension(prop, "http://id.who.int/icd11/extensions/repeats", o.get("allowMultipleValues").getAsBoolean());
+        ToolingExtensions.addBooleanExtension(prop, "http://id.who.int/icd11/extensions/repeats", o.asBoolean("allowMultipleValues"));
         if (o.has("scaleEntity")) {
           ToolingExtensions.addUriExtension(prop, "http://id.who.int/icd11/extensions/valueSet", buildValueSet(cs, cc.getCode(), name, o, dest));
         }
       }
     }
     if (entity.has("child")) {
-      for (JsonElement child : entity.getAsJsonArray("child")) {
+      for (JsonElement child : entity.getJsonArray("child")) {
-        processMMSEntity(cs, base, child.getAsString(), cc.addConcept(), dest);
+        processMMSEntity(cs, base, child.asString(), cc.addConcept(), dest);
       }
     }
   }
@@ -279,8 +278,8 @@ public class ICD11Generator {
     vs.setStatus(cs.getStatus());
     ConceptSetComponent inc = vs.getCompose().addInclude();
     inc.setSystem(cs.getUrl());
-    for (JsonElement e : o.getAsJsonArray("scaleEntity")) {
+    for (JsonElement e : o.getJsonArray("scaleEntity")) {
-      inc.addFilter().setProperty("concept").setOp(FilterOperator.ISA).setValue(tail(e.getAsString()));
+      inc.addFilter().setProperty("concept").setOp(FilterOperator.ISA).setValue(tail(e.asString()));
     }
     new XmlParser(XmlVersion.V1_1).setOutputStyle(OutputStyle.PRETTY).compose(new FileOutputStream(Utilities.path(dest, "vs-" + id + ".xml")), vs);
     return url;
@@ -328,12 +327,12 @@ public class ICD11Generator {
   }
 
   private String readString(JsonObject obj, String name) {
-    JsonObject p = obj.getAsJsonObject(name);
+    JsonObject p = obj.getJsonObject(name);
     if (p == null) {
       return null;
     }
     if (p.has("@value")) {
-      return p.get("@value").getAsString();
+      return p.get("@value").asString();
     }
     return null;
   }
@@ -400,7 +399,7 @@ public class ICD11Generator {
     http.addHeader("Accept-Language", "en");
     HTTPResult res = http.get(source, "application/json");
     res.checkThrowException();
-    return JsonTrackingParser.parseJson(res.getContent());
+    return JsonParser.parseObject(res.getContent());
   }
 
 

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/JsonProcessor.java

@@ -1,11 +1,12 @@
 package org.hl7.fhir.convertors.misc;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 
-import com.google.gson.JsonObject;
 
 public class JsonProcessor {
   public static void main(String[] args) throws Exception {
@@ -13,9 +14,9 @@ public class JsonProcessor {
   }
 
   private void process(String source) throws IOException {
-    JsonObject json = JsonTrackingParser.parseJsonFile(source);
+    JsonObject json = JsonParser.parseObjectFromFile(source);
     process(json);
-    JsonTrackingParser.write(json, new File(source), true);
+    JsonParser.compose(json, new FileOutputStream(source), true);
     
   }
 
@@ -178,11 +179,11 @@ public class JsonProcessor {
   }
 
   private void process(JsonObject json, String name) {
-    JsonObject j = json.getAsJsonObject(name);
+    JsonObject j = json.getJsonObject(name);
     if (j == null) {
       System.out.println("Can't find "+name);
     } else {
-      j.addProperty("modifier", true);
+      j.add("modifier", true);
     }
     
   }

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/NpmPackageVersionConverter.java

@@ -29,13 +29,12 @@ import org.hl7.fhir.convertors.factory.VersionConvertorFactory_30_50;
 import org.hl7.fhir.convertors.factory.VersionConvertorFactory_40_50;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.VersionUtilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.NpmPackageIndexBuilder;
 
 import com.google.common.base.Charsets;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
 
 public class NpmPackageVersionConverter {
 
@@ -105,7 +104,7 @@ public class NpmPackageVersionConverter {
       if (!e.getKey().equals("package/package.json")) {
         byte[] cnv = e.getValue();
         try {
-          JsonObject json = JsonTrackingParser.parseJson(e.getValue());
+          JsonObject json = JsonParser.parseObject(e.getValue());
           if (json.has("resourceType")) {
             cnv = convertResource(e.getKey(), e.getValue());
           }
@@ -174,11 +173,11 @@ public class NpmPackageVersionConverter {
   }
 
   private byte[] convertPackage(byte[] cnt) throws IOException {
-    JsonObject json = JsonTrackingParser.parseJson(cnt);
+    JsonObject json = JsonParser.parseObject(cnt);
-    currentVersion = json.getAsJsonArray("fhirVersions").get(0).getAsString();
+    currentVersion = json.getJsonArray("fhirVersions").get(0).asString();
-    String name = JsonUtilities.str(json, "name");
+    String name = json.asString("name");
     json.remove("name");
-    json.addProperty("name", name + "." + vCode);
+    json.add("name", name + "." + vCode);
     json.remove("fhirVersions");
     json.remove("dependencies");
     JsonArray fv = new JsonArray();
@@ -186,8 +185,8 @@ public class NpmPackageVersionConverter {
     fv.add(version);
     JsonObject dep = new JsonObject();
     json.add("dependencies", dep);
-    dep.addProperty(VersionUtilities.packageForVersion(version), version);
+    dep.add(VersionUtilities.packageForVersion(version), version);
-    return JsonTrackingParser.write(json).getBytes(Charsets.UTF_8);
+    return JsonParser.composeBytes(json);
   }
 
   private byte[] convertResource(String n, byte[] cnt) {

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/PackageMaintainer.java

@@ -7,7 +7,8 @@ import java.util.List;
 
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 
 /*
   Copyright (c) 2011+, HL7, Inc.
@@ -38,11 +39,6 @@ import org.hl7.fhir.utilities.json.JsonTrackingParser;
   
  */
 
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonObject;
-
 public class PackageMaintainer {
 
 
@@ -96,11 +92,10 @@ public class PackageMaintainer {
       if (f.isDirectory())
         strip(f);
       else if (f.getName().endsWith(".json")) {
-        JsonObject json = JsonTrackingParser.parseJson(f);
+        JsonObject json = JsonParser.parseObject(f);
         if (json.has("resourceType") && json.has("text")) {
           json.remove("text");
-          Gson gson = new GsonBuilder().create();
+          String src = JsonParser.compose(json);
-          String src = gson.toJson(json);
           TextFile.stringToFile(src, f.getAbsolutePath());
         }
       }

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/XMLPackageConvertor.java

@@ -5,12 +5,10 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.Map.Entry;
 
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.model.JsonProperty;
 import org.hl7.fhir.utilities.npm.NpmPackage;
 
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-
-
 public class XMLPackageConvertor {
 
   public static void main(String[] args) throws IOException {
@@ -26,13 +24,13 @@ public class XMLPackageConvertor {
           System.out.println("Package " + f.getAbsolutePath());
           NpmPackage p = NpmPackage.fromPackage(new FileInputStream(f));
           if (p.getNpm().has("dependencies")) {
-            JsonObject dep = p.getNpm().getAsJsonObject("dependencies");
+            JsonObject dep = p.getNpm().getJsonObject("dependencies");
-            if (dep.entrySet().isEmpty()) {
+            if (dep.getProperties().isEmpty()) {
               System.out.println("  Dependencies: none");
             } else {
               System.out.println("  Dependencies:");
-              for (Entry<String, JsonElement> e : dep.entrySet()) {
+              for (JsonProperty e : dep.getProperties()) {
-                System.out.println("    " + e.getKey() + ": " + e.getValue().getAsString());
+                System.out.println("    " + e.getName() + ": " + e.getValue().toString());
               }
             }
           } else {

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/misc/xver/CorePackageVersionConvertor.java

@@ -17,13 +17,12 @@ import org.hl7.fhir.convertors.factory.VersionConvertorFactory_40_50;
 import org.hl7.fhir.convertors.misc.xver.CorePackageVersionConvertor.BaseConvertor;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.VersionUtilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.NpmPackage;
 import org.hl7.fhir.utilities.npm.NpmPackage.NpmPackageFolder;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
 
 public class CorePackageVersionConvertor {
 
@@ -582,13 +581,13 @@ public class CorePackageVersionConvertor {
   }
 
   private byte[] convertPackage(byte[] cnt, String version) throws IOException {
-    JsonObject json = JsonTrackingParser.parseJson(cnt);
+    JsonObject json = JsonParser.parseObject(cnt);
     json.remove("fhir-version-list");
     JsonArray vl = new JsonArray();
     json.add("fhirVersions", vl);
     vl.add(version);
-    json.addProperty("name", JsonUtilities.str(json, "name")+".as."+VersionUtilities.getNameForVersion(version).toLowerCase());
+    json.add("name", json.asString("name")+".as."+VersionUtilities.getNameForVersion(version).toLowerCase());
-    json.addProperty("title", JsonUtilities.str(json, "title")+" (as Version "+VersionUtilities.getNameForVersion(version).toLowerCase()+")");
+    json.add("title", json.asString("title")+" (as Version "+VersionUtilities.getNameForVersion(version).toLowerCase()+")");
-    return JsonTrackingParser.write(json).getBytes(StandardCharsets.UTF_8);
+    return JsonParser.composeBytes(json);
   }
 }

org.hl7.fhir.dstu3/src/main/java/org/hl7/fhir/dstu3/context/SimpleWorkerContext.java

@@ -156,7 +156,7 @@ public class SimpleWorkerContext extends BaseWorkerContext implements IWorkerCon
   public static SimpleWorkerContext fromPackage(NpmPackage pi, IContextResourceLoader loader) throws FileNotFoundException, IOException, FHIRException {
     SimpleWorkerContext res = new SimpleWorkerContext();
     res.setAllowLoadingDuplicates(true);
-    res.version = pi.getNpm().get("version").getAsString();
+    res.version = pi.getNpm().asString("version");
     res.loadFromPackage(pi, loader);
     return res;
   }

org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/context/SimpleWorkerContext.java

@@ -163,7 +163,7 @@ public class SimpleWorkerContext extends BaseWorkerContext implements IWorkerCon
   public static SimpleWorkerContext fromPackage(NpmPackage pi, IContextResourceLoader loader) throws FileNotFoundException, IOException, FHIRException {
     SimpleWorkerContext res = new SimpleWorkerContext();
     res.setAllowLoadingDuplicates(true);
-    res.version = pi.getNpm().get("version").getAsString();
+    res.version = pi.getNpm().asString("version");
     res.loadFromPackage(pi, loader);
     return res;
   }

org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/context/SimpleWorkerContext.java

@@ -216,7 +216,7 @@ public class SimpleWorkerContext extends BaseWorkerContext implements IWorkerCon
   public static SimpleWorkerContext fromPackage(NpmPackage pi, IContextResourceLoader loader) throws FileNotFoundException, IOException, FHIRException {
     SimpleWorkerContext res = new SimpleWorkerContext();
     res.setAllowLoadingDuplicates(true);
-    res.version = pi.getNpm().get("version").getAsString();
+    res.version = pi.getNpm().asString("version");
     res.loadFromPackage(pi, loader);
     res.finishLoading();
     return res;

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/SimpleWorkerContext.java

@@ -250,7 +250,7 @@ public class SimpleWorkerContext extends BaseWorkerContext implements IWorkerCon
     public SimpleWorkerContext fromPackage(NpmPackage pi, IContextResourceLoader loader) throws IOException, FHIRException {
       SimpleWorkerContext context = getSimpleWorkerContextInstance();
       context.setAllowLoadingDuplicates(allowLoadingDuplicates);
-      context.version = pi.getNpm().get("version").getAsString();
+      context.version = pi.getNpm().asString("version");
       context.loadFromPackage(pi, loader);
       context.finishLoading();
       return build(context);

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/NPMPackageGenerator.java

@@ -62,16 +62,14 @@ import org.hl7.fhir.r5.model.ImplementationGuide.ImplementationGuideDependsOnCom
 import org.hl7.fhir.utilities.CommaSeparatedStringBuilder;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.json.model.JsonArray;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.model.JsonString;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.NpmPackageIndexBuilder;
 import org.hl7.fhir.utilities.npm.ToolsVersion;
 import org.hl7.fhir.utilities.npm.PackageGenerator.PackageType;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonPrimitive;
-
 public class NPMPackageGenerator {
 
   public enum Category {
@@ -118,13 +116,13 @@ public class NPMPackageGenerator {
   public static NPMPackageGenerator subset(NPMPackageGenerator master, String destFile, String id, String name, Date date, boolean notForPublication) throws FHIRException, IOException {
     JsonObject p = master.packageJ.deepCopy();
     p.remove("name");
-    p.addProperty("name", id);
+    p.add("name", id);
     p.remove("type");
-    p.addProperty("type", PackageType.CONFORMANCE.getCode());    
+    p.add("type", PackageType.CONFORMANCE.getCode());    
     p.remove("title");
-    p.addProperty("title", name);
+    p.add("title", name);
     if (notForPublication) {
-      p.addProperty("notForPublication", true);
+      p.add("notForPublication", true);
     }
 
     return new NPMPackageGenerator(destFile, p, date, notForPublication);
@@ -142,17 +140,16 @@ public class NPMPackageGenerator {
     String dt = new SimpleDateFormat("yyyyMMddHHmmss").format(date);
     packageJ = npm;
     packageManifest = new JsonObject();
-    packageManifest.addProperty("version", npm.get("version").getAsString());
+    packageManifest.set("version", npm.asString("version"));
-    packageManifest.addProperty("date", dt);
+    packageManifest.set("date", dt);
     if (notForPublication) {
-      packageManifest.addProperty("notForPublication", true);
+      packageManifest.add("notForPublication", true);
     }
-    npm.addProperty("date", dt);
+    npm.set("date", dt);
-    packageManifest.addProperty("name", npm.get("name").getAsString());
+    packageManifest.set("name", npm.asString("name"));
     this.destFile = destFile;
     start();
-    Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    String json = JsonParser.compose(npm, true);
-    String json = gson.toJson(npm);
     try {
       addFile(Category.RESOURCE, "package.json", json.getBytes("UTF-8"));
     } catch (UnsupportedEncodingException e) {
@@ -183,31 +180,31 @@ public class NPMPackageGenerator {
     }
 
     JsonObject npm = new JsonObject();
-    npm.addProperty("name", ig.getPackageId());
+    npm.add("name", ig.getPackageId());
-    npm.addProperty("version", ig.getVersion());
+    npm.add("version", ig.getVersion());
     igVersion = ig.getVersion();
-    npm.addProperty("tools-version", ToolsVersion.TOOLS_VERSION);
+    npm.add("tools-version", ToolsVersion.TOOLS_VERSION);
-    npm.addProperty("type", kind.getCode());
+    npm.add("type", kind.getCode());
-    npm.addProperty("date", dt);
+    npm.add("date", dt);
     if (ig.hasLicense()) {
-      npm.addProperty("license", ig.getLicense().toCode());
+      npm.add("license", ig.getLicense().toCode());
     }
-    npm.addProperty("canonical", canonical);
+    npm.add("canonical", canonical);
     if (notForPublication) {
-      npm.addProperty("notForPublication", true);
+      npm.add("notForPublication", true);
     }
-    npm.addProperty("url", web);
+    npm.add("url", web);
     if (ig.hasTitle()) {
-      npm.addProperty("title", ig.getTitle());
+      npm.add("title", ig.getTitle());
     }
     if (ig.hasDescription()) {
-      npm.addProperty("description", ig.getDescription()+ " (built "+dtHuman+timezone()+")");
+      npm.add("description", ig.getDescription()+ " (built "+dtHuman+timezone()+")");
     }
     JsonArray vl = new JsonArray();
     
     npm.add("fhirVersions", vl);
     for (String v : fhirVersion) { 
-      vl.add(new JsonPrimitive(v));
+      vl.add(new JsonString(v));
     }
     
     if (kind != PackageType.CORE) {
@@ -216,15 +213,15 @@ public class NPMPackageGenerator {
       for (String v : fhirVersion) { 
         String vp = packageForVersion(v);
         if (vp != null ) {
-          dep.addProperty(vp, v);
+          dep.add(vp, v);
         }
       }
       for (ImplementationGuideDependsOnComponent d : ig.getDependsOn()) {
-        dep.addProperty(d.getPackageId(), d.getVersion());
+        dep.add(d.getPackageId(), d.getVersion());
       }
     }
     if (ig.hasPublisher()) {
-      npm.addProperty("author", ig.getPublisher());
+      npm.add("author", ig.getPublisher());
     }
     JsonArray m = new JsonArray();
     for (ContactDetail t : ig.getContact()) {
@@ -233,23 +230,22 @@ public class NPMPackageGenerator {
       if (t.hasName() & (email != null || url != null)) {
         JsonObject md = new JsonObject();
         m.add(md);
-        md.addProperty("name", t.getName());
+        md.add("name", t.getName());
         if (email != null)
-          md.addProperty("email", email);
+          md.add("email", email);
         if (url != null)
-          md.addProperty("url", url);
+          md.add("url", url);
       }
     }
     if (m.size() > 0)
       npm.add("maintainers", m);
     if (ig.getManifest().hasRendering())
-      npm.addProperty("homepage", ig.getManifest().getRendering());
+      npm.add("homepage", ig.getManifest().getRendering());
     JsonObject dir = new JsonObject();
     npm.add("directories", dir);
-    dir.addProperty("lib", "package");
+    dir.add("lib", "package");
-    dir.addProperty("example", "example");
+    dir.add("example", "example");
-    Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    String json = JsonParser.compose(npm, true);
-    String json = gson.toJson(npm);
     try {
       addFile(Category.RESOURCE, "package.json", json.getBytes("UTF-8"));
     } catch (UnsupportedEncodingException e) {
@@ -257,14 +253,14 @@ public class NPMPackageGenerator {
     packageJ = npm;
 
     packageManifest = new JsonObject();
-    packageManifest.addProperty("version", ig.getVersion());
+    packageManifest.add("version", ig.getVersion());
     JsonArray fv = new JsonArray();
     for (String v : fhirVersion) {
       fv.add(v);
     }
     packageManifest.add("fhirVersion", fv);
-    packageManifest.addProperty("date", dt);
+    packageManifest.add("date", dt);
-    packageManifest.addProperty("name", ig.getPackageId());
+    packageManifest.add("name", ig.getPackageId());
 
   }
 
@@ -380,8 +376,7 @@ public class NPMPackageGenerator {
     OutputStream.close();
     TextFile.bytesToFile(OutputStream.toByteArray(), destFile);
     // also, for cache management on current builds, generate a little manifest
-    Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    String json = JsonParser.compose(packageManifest, true);
-    String json = gson.toJson(packageManifest);
     TextFile.stringToFile(json, Utilities.changeFileExt(destFile, ".manifest.json"), false);
   }
 

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/XVerExtensionManager.java

@@ -62,9 +62,9 @@ public class XVerExtensionManager {
       }
     }
     JsonObject root = lists.get(v);
-    JsonObject path = root.getObject(e);
+    JsonObject path = root.getJsonObject(e);
     if (path == null) {
-      path = root.getObject(e+"[x]");      
+      path = root.getJsonObject(e+"[x]");      
     }
     if (path == null) {
       return XVerExtensionStatus.Unknown;
@@ -85,9 +85,9 @@ public class XVerExtensionManager {
     String verTarget = VersionUtilities.getMajMin(context.getVersion());
     String e = url.substring(54);
     JsonObject root = lists.get(verSource);
-    JsonObject path = root.getObject(e);
+    JsonObject path = root.getJsonObject(e);
     if (path == null) {
-      path = root.getObject(e+"[x]");
+      path = root.getJsonObject(e+"[x]");
     }
     
     StructureDefinition sd = new StructureDefinition();
@@ -116,9 +116,9 @@ public class XVerExtensionManager {
       populateTypes(path, val, verSource, verTarget);
     } else if (path.has("elements")) {
       for (JsonElement i : path.forceArray("elements").getItems()) {
-        JsonObject elt = root.getObject(e+"."+i.toString());
+        JsonObject elt = root.getJsonObject(e+"."+i.asString());
         if (elt != null) {
-        String s = i.toString().replace("[x]", "");
+        String s = i.asString().replace("[x]", "");
         sd.getDifferential().addElement().setPath("Extension.extension").setSliceName(s);
         sd.getDifferential().addElement().setPath("Extension.extension.extension").setMax("0");
         sd.getDifferential().addElement().setPath("Extension.extension.url").setFixed(new UriType(s));
@@ -144,7 +144,7 @@ public class XVerExtensionManager {
 
   public void populateTypes(JsonObject path, ElementDefinition val, String verSource, String verTarget) {
     for (JsonElement i : path.forceArray("types").getItems()) {
-      String s = i.toString();
+      String s = i.asString();
       if (!s.startsWith("!")) {
         if (s.contains("(")) {
           String t = s.substring(0, s.indexOf("("));

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonArray.java

@@ -1,12 +1,13 @@
 package org.hl7.fhir.utilities.json.model;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 import org.hl7.fhir.utilities.json.JsonException;
 
 
-public class JsonArray extends JsonElement {
+public class JsonArray extends JsonElement implements Iterable<JsonElement> {
   private List<JsonElement> items = new ArrayList<>();
   private List<Boolean> noCommas; // validator use
   private List<Boolean> unQuoted; // validator use
@@ -15,7 +16,7 @@ public class JsonArray extends JsonElement {
     List<String> list = new ArrayList<>();
     for (JsonElement n : items) {
       if (n instanceof JsonPrimitive) {
-        list.add(n.toString());
+        list.add(n.asJsonPrimitive().getValue());
       }
     }
     return list;
@@ -25,7 +26,7 @@ public class JsonArray extends JsonElement {
     return items;
   }
 
-  public List<JsonObject> asObjects() {
+  public List<JsonObject> asJsonObjects() {
     List<JsonObject> list = new ArrayList<>();
     for (JsonElement n : items) {
       if (n instanceof JsonObject) {
@@ -79,11 +80,50 @@ public class JsonArray extends JsonElement {
 
 
   public JsonObject findByStringProp(JsonArray arr, String prop, String value) {
-    for (JsonObject obj : asObjects()) {
+    for (JsonObject obj : asJsonObjects()) {
-      if (obj.has(prop) && value.equals(obj.getString(prop))) 
+      if (obj.has(prop) && value.equals(obj.asString(prop))) 
         return obj;
     }
     return null;
   }
   
+  public Iterator<JsonElement> iterator() {
+    return items.iterator();
+  }
+
+  public JsonElement get(int i) {
+    return items.get(i);
+  }
+
+  public JsonArray deepCopy() {
+    return (JsonArray) make().copy(this);
+  }
+
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    JsonArray o = (JsonArray) other;
+    for (JsonElement p : o.getItems()) {
+      add(p.deepCopy());
+    }
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonArray();
+  }
+  
+  @Override
+  public String toString() {
+    StringBuilder b = new StringBuilder();
+    b.append("[ ");
+    boolean first = true;
+    for (JsonElement p : items) {
+      if (first) first = false; else b.append(", ");
+      b.append(p.toString());
+    }
+    b.append(" ]");
+    return b.toString();
+  }
+  
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonBoolean.java

@@ -8,6 +8,9 @@ public class JsonBoolean extends JsonPrimitive {
     this.value = value;
   }
 
+  private JsonBoolean() {
+  }
+
   public JsonElementType elementType() {
     return JsonElementType.BOOLEAN;
   }
@@ -20,6 +23,7 @@ public class JsonBoolean extends JsonPrimitive {
     this.value = value;
   }
   
+  @Override
   public String getValue() {
     return value ? "true" : "false";
   }
@@ -28,4 +32,15 @@ public class JsonBoolean extends JsonPrimitive {
   public String toString() {
     return getValue();
   }
+  
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    value = ((JsonBoolean) other).value;
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonBoolean();
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonComment.java

@@ -1,5 +0,0 @@
-package org.hl7.fhir.utilities.json.model;
-
-public class JsonComment {
-
-}

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonElement.java

@@ -45,4 +45,71 @@ public abstract class JsonElement {
   public boolean hasComments() {
     return comments != null && !comments.isEmpty();
   }
+  
+  public JsonElement deepCopy() {
+    return make().copy(this);
+  }
+  
+  protected abstract JsonElement copy(JsonElement jsonElement);
+  protected abstract JsonElement make();
+  
+  public boolean isJsonObject() {
+    return elementType() == JsonElementType.OBJECT;
+  }
+  
+  public boolean isJsonArray() {
+    return elementType() == JsonElementType.ARRAY;
+  }
+  
+  public boolean isJsonPrimitive() {
+    return isJsonBoolean() || isJsonString() || isJsonNull() || isJsonNumber();
+  }
+
+  public boolean isJsonBoolean() {
+    return elementType() == JsonElementType.BOOLEAN;
+  }
+
+  public boolean isJsonString() {
+    return elementType() == JsonElementType.STRING;
+  }
+
+  public boolean isJsonNumber() {
+    return elementType() == JsonElementType.NUMBER;
+  }
+
+  public boolean isJsonNull() {
+    return elementType() == JsonElementType.NULL;
+  }
+
+  public JsonObject asJsonObject() {
+    return isJsonObject() ? (JsonObject) this : null;
+  }
+
+  public JsonArray asJsonArray() {
+    return isJsonArray() ? (JsonArray) this : null;
+  }
+  
+  public JsonPrimitive asJsonPrimitive() {
+    return isJsonPrimitive() ? (JsonPrimitive) this : null;
+  }
+
+  public JsonBoolean asJsonBoolean() {
+    return isJsonBoolean() ? (JsonBoolean) this : null;
+  }
+
+  public JsonString asJsonString() {
+    return isJsonString() ? (JsonString) this : null;
+  }
+
+  public JsonNumber asJsonNumber() {
+    return isJsonNumber() ? (JsonNumber) this : null;
+  }
+
+  public JsonNull asJsonNull() {
+    return isJsonNull() ? (JsonNull) this : null;
+  }
+
+  public String asString() {
+    return isJsonPrimitive() ? ((JsonPrimitive) this).getValue() : null;
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonNull.java

@@ -6,7 +6,7 @@ public class JsonNull extends JsonPrimitive {
     return JsonElementType.NULL;
   }
 
-
+  @Override
   public String getValue() {
     return "null";
   }
@@ -15,4 +15,14 @@ public class JsonNull extends JsonPrimitive {
   public String toString() {
     return getValue();
   }
+    
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonNull();
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonNumber.java

@@ -10,10 +10,18 @@ public class JsonNumber extends JsonPrimitive {
     this.value = value;
   }
 
+  public JsonNumber(int value) {
+    this.value = Integer.toString(value);
+  }
+
+  private JsonNumber() {
+  }
+
   public JsonElementType elementType() {
     return JsonElementType.NUMBER;
   }
 
+  @Override
   public String getValue() {
     return value;
   }
@@ -30,4 +38,15 @@ public class JsonNumber extends JsonPrimitive {
       return null; 
     }
   }
+  
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    value = ((JsonNumber) other).value;
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonNumber();
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonObject.java

@@ -1,9 +1,12 @@
 package org.hl7.fhir.utilities.json.model;
 
+import java.time.Instant;
+import java.time.OffsetDateTime;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.json.JsonException;
@@ -19,8 +22,8 @@ public class JsonObject extends JsonElement {
   }
 
   public JsonObject add(String name, JsonElement value) throws JsonException {
-    check(name != null, "Numm is null");
+    check(name != null, "Name is null");
-    check(value != null, "Numm is null");
+    check(value != null, "Value is null");
     check(get(name) == null, "Name '"+name+"' already exists");
     JsonProperty p = new JsonProperty(name, value);
     properties.add(p);
@@ -30,8 +33,8 @@ public class JsonObject extends JsonElement {
 
   // this is used by the parser which can allow duplicates = true (for the validator). You should not otherwise use it
   public JsonObject addForParser(String name, JsonElement value, boolean noComma, boolean nameUnquoted, boolean valueUnquoted) throws JsonException {
-    check(name != null, "Numm is null");
+    check(name != null, "Name is null");
-    check(value != null, "Numm is null");
+    check(value != null, "Value is null");
     JsonProperty p = new JsonProperty(name, value);
     p.setNoComma(noComma);
     p.setUnquotedName(nameUnquoted);
@@ -42,13 +45,64 @@ public class JsonObject extends JsonElement {
   }
 
   public JsonObject add(String name, String value) throws JsonException {
+    check(name != null, "Name is null");
     return add(name, new JsonString(value));
   }
 
   public JsonObject add(String name, boolean value) throws JsonException {
+    check(name != null, "Name is null");
     return add(name, new JsonBoolean(value));
   }
 
+  public JsonObject add(String name, int value) throws JsonException {
+    check(name != null, "Name is null");
+    return add(name, new JsonNumber(value));
+  }
+
+  public JsonObject set(String name, JsonElement value) throws JsonException {
+    check(name != null, "Name is null");
+    check(value != null, "Value is null");
+    JsonProperty p = propMap.get(name);
+    if (p != null) {
+      p.setValue(value);
+      return this;
+    } else {
+      return add(name, value);
+    }
+  }
+
+  public JsonObject set(String name, String value) throws JsonException {
+    check(name != null, "Name is null");
+    JsonProperty p = propMap.get(name);
+    if (p != null) {
+      p.setValue(new JsonString(value));
+      return this;
+    } else {
+      return add(name, new JsonString(value));
+    }
+  }
+
+  public JsonObject set(String name, boolean value) throws JsonException {
+    check(name != null, "Name is null");
+    JsonProperty p = propMap.get(name);
+    if (p != null) {
+      p.setValue(new JsonBoolean(value));
+      return this;
+    } else {
+      return add(name, new JsonBoolean(value));
+    }
+  }
+
+  public JsonObject set(String name, int value) throws JsonException {
+    check(name != null, "Name is null");
+    JsonProperty p = propMap.get(name);
+    if (p != null) {
+      p.setValue(new JsonNumber(value));
+      return this;
+    } else {
+      return add(name, new JsonNumber(value));
+    }
+  }
 
   public JsonElement get(String name) {
     if (propMap.containsKey(name)) {
@@ -62,7 +116,7 @@ public class JsonObject extends JsonElement {
     return propMap.containsKey(name);
   }
 
-  public void drop(String name) {
+  public void remove(String name) {
     if (propMap.containsKey(name)) {
       propMap.remove(name);
       properties.removeIf((JsonProperty item) -> name.equals(item.getName()));
@@ -74,8 +128,8 @@ public class JsonObject extends JsonElement {
   }
 
   public String str(String name) {
-    if (has(name)) {
+    if (hasPrimitive(name)) {
-      return get(name).toString();
+      return get(name).asJsonPrimitive().getValue();
     } else {
       return null;
     }
@@ -110,27 +164,27 @@ public class JsonObject extends JsonElement {
   }
 
 
-  public JsonObject getObject(String name) {
+  public JsonObject getJsonObject(String name) {
     return hasObject(name) ?  (JsonObject) get(name) : null;
   }
 
-  public JsonString getString(String name) {
+  public JsonString getJsonString(String name) {
     return hasString(name) ? (JsonString) get(name) : null;
   }
 
-  public JsonBoolean getBoolean(String name) {
+  public JsonBoolean getJsonBoolean(String name) {
     return hasBoolean(name) ? (JsonBoolean) get(name) : null;
   }
   
-  public JsonNumber getNumber(String name) {
+  public JsonNumber getJsonNumber(String name) {
     return hasNumber(name) ? (JsonNumber) get(name) : null;
   }
   
-  public JsonNull getNull(String name) {
+  public JsonNull getJsonNull(String name) {
     return hasNull(name) ?(JsonNull) get(name) : null;
   }
   
-  public JsonArray getArray(String name) {
+  public JsonArray getJsonArray(String name) {
     return hasArray(name) ? (JsonArray) get(name) : null;
   }
 
@@ -148,7 +202,16 @@ public class JsonObject extends JsonElement {
   }
 
   public String asString(String name) {
-    return hasPrimitive(name) ? ((JsonPrimitive) get(name)).toString() : null;
+    return hasPrimitive(name) ? ((JsonPrimitive) get(name)).getValue() : null;
+  }
+
+  public String asString(String... names) {
+    for (String n : names) {
+      if (hasPrimitive(n)) {
+        return asString(n);
+      }
+    }
+    return null;
   }
 
   public boolean asBoolean(String name) {
@@ -167,25 +230,101 @@ public class JsonObject extends JsonElement {
     return false;
   }
 
+  public Instant asDate(String name) {
+    String source = asString(name);
+    if (Utilities.noString(source)) {
+      return null;
+    } else {
+      OffsetDateTime odt = OffsetDateTime.parse(source);
+      return odt.toInstant();
+    }
+  }
+  
   public JsonObject forceObject(String name) throws JsonException {
     if (has(name) && !hasObject(name)) {
-      drop(name);
+      remove(name);
     }
     if (!has(name)) {
       add(name, new JsonObject());
     }
-    return getObject(name);
+    return getJsonObject(name);
   }
 
   public JsonArray forceArray(String name) throws JsonException {
     if (has(name) && !hasArray(name)) {
-      drop(name);
+      remove(name);
     }
     if (!has(name)) {
       add(name, new JsonArray());
     }
-    return getArray(name);
+    return getJsonArray(name);
+  }
+
+  public List<JsonObject> getJsonObjects(String name) {
+    List<JsonObject> res = new ArrayList<>();
+    if (hasArray(name)) {
+      res.addAll(getJsonArray(name).asJsonObjects());
+    } else if (hasObject(name)) {
+      res.add(getJsonObject(name));
+    } 
+    return res;
   }
   
+  public List<String> getStrings(String name) {
+    List<String> res = new ArrayList<>();
+    if (hasArray(name)) {
+      res.addAll(getJsonArray(name).asStrings());
+    } else if (hasPrimitive(name)) {
+      res.add(asString(name));
+    } 
+    return res;
+  }
+  
+  public JsonObject deepCopy() {
+    return (JsonObject) make().copy(this);
+  }
 
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    JsonObject o = (JsonObject) other;
+    for (JsonProperty p : o.getProperties()) {
+      add(p.getName(), p.getValue().deepCopy());
+    }
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonObject();
+  }
+  
+  public void merge(JsonObject source) {
+    for (JsonProperty pp : source.getProperties()) {
+      if (has(pp.getName())) {
+        JsonElement te = get(pp.getName());
+        if (te.isJsonObject() && pp.getValue().isJsonObject()) {
+          ((JsonObject) te).merge((JsonObject) pp.getValue());
+        } else {
+          set(pp.getName(), pp.getValue());
+        }
+      } else {
+        add(pp.getName(), pp.getValue());
+      }
+    }
+  }
+
+
+  @Override
+  public String toString() {
+    StringBuilder b = new StringBuilder();
+    b.append("{ ");
+    boolean first = true;
+    for (JsonProperty p : properties) {
+      if (first) first = false; else b.append(", ");
+      b.append(p.toString());
+    }
+    b.append(" }");
+    return b.toString();
+  }
+  
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonPrimitive.java

@@ -2,4 +2,9 @@ package org.hl7.fhir.utilities.json.model;
 
 public abstract class JsonPrimitive extends JsonElement {
 
+  public abstract String getValue();
+  
+  public String toJson() {
+    return getValue();
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonProperty.java

@@ -49,5 +49,10 @@ public class JsonProperty {
   public void setUnquotedValue(boolean unquotedValue) {
     this.unquotedValue = unquotedValue;
   }
+
+  @Override
+  public String toString() {
+    return "\""+name+"\" : "+value.toString();
+  }
   
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/model/JsonString.java

@@ -1,5 +1,7 @@
 package org.hl7.fhir.utilities.json.model;
 
+import org.hl7.fhir.utilities.Utilities;
+
 public class JsonString extends JsonPrimitive {
   private String value;
 
@@ -8,10 +10,14 @@ public class JsonString extends JsonPrimitive {
     this.value = value;
   }
 
+  private JsonString() {
+  }
+
   public JsonElementType elementType() {
     return JsonElementType.STRING;
   }
 
+  @Override
   public String getValue() {
     return value;
   }
@@ -22,7 +28,23 @@ public class JsonString extends JsonPrimitive {
 
   @Override
   public String toString() {
-    return value;
+    throw new Error("This should not be called");
+    // return "\""+ Utilities.escapeJson(value)+"\"";
   }
 
+  @Override
+  public String toJson() {
+    return "\""+ Utilities.escapeJson(value)+"\"";
+  }
+  
+  @Override
+  protected JsonElement copy(JsonElement other) {
+    value = ((JsonString) other).value;
+    return this;
+  }
+  
+  @Override
+  protected JsonElement make() {
+    return new JsonString();
+  }
 }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/json/parser/JsonParser.java

@@ -220,8 +220,11 @@ public class JsonParser {
       lexer.next();
       lexer.getStates().push(new State("", true));
     } 
-    else
+    else if (lexer.getType() != null) {
       throw lexer.error("Unexpected content at start of JSON: "+lexer.getType().toString());
+    } else {
+      throw lexer.error("Unexpected content at start of JSON");      
+    }
 
     if (lexer.getType() != TokenType.Close) {
       parseProperty();
@@ -568,7 +571,7 @@ public class JsonParser {
         int length = 0;
         for (JsonElement i : arr.getItems()) {
           if (i instanceof JsonPrimitive) {
-            length = length + i.toString().length();
+            length = length + ((JsonPrimitive)i).toJson().length();
           }
           if (i.elementType() == JsonElementType.ARRAY || i.elementType() == JsonElementType.OBJECT
               || i.hasComments()) { // 20 is a somewhat arbitrary cut off

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/FilesystemPackageCacheManager.java

@@ -32,8 +32,10 @@ import org.hl7.fhir.utilities.SimpleHTTPClient.HTTPResult;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.VersionUtilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonElement;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.NpmPackage.NpmPackageFolder;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -67,12 +69,6 @@ import org.slf4j.LoggerFactory;
   
  */
 
-
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-
 /**
  * This is a package cache manager implementation that uses a local disk cache
  *
@@ -420,18 +416,18 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
             log(" done.");
         }
         pck = loadPackageInfo(packRoot);
-        if (!id.equals(JsonUtilities.str(npm.getNpm(), "name")) || !v.equals(JsonUtilities.str(npm.getNpm(), "version"))) {
+        if (!id.equals(npm.getNpm().asString("name")) || !v.equals(npm.getNpm().asString("version"))) {
-          if (!id.equals(JsonUtilities.str(npm.getNpm(), "name"))) {
+          if (!id.equals(npm.getNpm().asString("name"))) {
-            npm.getNpm().addProperty("original-name", JsonUtilities.str(npm.getNpm(), "name"));
+            npm.getNpm().add("original-name", npm.getNpm().asString("name"));
             npm.getNpm().remove("name");
-            npm.getNpm().addProperty("name", id);
+            npm.getNpm().add("name", id);
           }
-          if (!v.equals(JsonUtilities.str(npm.getNpm(), "version"))) {
+          if (!v.equals(npm.getNpm().asString("version"))) {
-            npm.getNpm().addProperty("original-version", JsonUtilities.str(npm.getNpm(), "version"));
+            npm.getNpm().add("original-version", npm.getNpm().asString("version"));
             npm.getNpm().remove("version");
-            npm.getNpm().addProperty("version", v);
+            npm.getNpm().add("version", v);
           }
-          TextFile.stringToFile(new GsonBuilder().setPrettyPrinting().create().toJson(npm.getNpm()), Utilities.path(cacheFolder, id + "#" + v, "package", "package.json"), false);
+          TextFile.stringToFile(JsonParser.compose(npm.getNpm(), true), Utilities.path(cacheFolder, id + "#" + v, "package", "package.json"), false);
         }
       } catch (Exception e) {
         try {
@@ -570,10 +566,9 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
 
   private String getPackageUrlFromBuildList(String packageId) throws IOException {
     checkBuildLoaded();
-    for (JsonElement n : buildInfo) {
+    for (JsonObject o : buildInfo.asJsonObjects()) {
-      JsonObject o = (JsonObject) n;
+      if (packageId.equals(o.asString("package-id"))) {
-      if (packageId.equals(JsonUtilities.str(o, "package-id"))) {
+        return o.asString("url");
-        return JsonUtilities.str(o, "url");
       }
     }
     return null;
@@ -583,8 +578,8 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     checkBuildLoaded();
     for (JsonElement n : buildInfo) {
       JsonObject o = (JsonObject) n;
-      if (!specList.containsKey(JsonUtilities.str(o, "package-id"))) {
+      if (!specList.containsKey(o.asString("package-id"))) {
-        specList.put(JsonUtilities.str(o, "package-id"), JsonUtilities.str(o, "url"));
+        specList.put(o.asString("package-id"), o.asString("url"));
       }
     }
   }
@@ -609,9 +604,9 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     try {
       for (String pf : listPackages()) {
         if (new File(Utilities.path(cacheFolder, pf, "package", "package.json")).exists()) {
-          JsonObject npm = JsonTrackingParser.parseJsonFile(Utilities.path(cacheFolder, pf, "package", "package.json"));
+          JsonObject npm = JsonParser.parseObjectFromFile(Utilities.path(cacheFolder, pf, "package", "package.json"));
-          if (canonicalUrl.equals(JsonUtilities.str(npm, "canonical"))) {
+          if (canonicalUrl.equals(npm.asString("canonical"))) {
-            return JsonUtilities.str(npm, "name");
+            return npm.asString("name");
           }
         }
       }
@@ -630,14 +625,14 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     if (buildInfo != null) {
       for (JsonElement n : buildInfo) {
         JsonObject o = (JsonObject) n;
-        if (canonical.equals(JsonUtilities.str(o, "url"))) {
+        if (canonical.equals(o.asString("url"))) {
-          return JsonUtilities.str(o, "package-id");
+          return o.asString("package-id");
         }
       }
       for (JsonElement n : buildInfo) {
         JsonObject o = (JsonObject) n;
-        if (JsonUtilities.str(o, "url").startsWith(canonical + "/ImplementationGuide/")) {
+        if (o.asString("url").startsWith(canonical + "/ImplementationGuide/")) {
-          return JsonUtilities.str(o, "package-id");
+          return o.asString("package-id");
         }
       }
     }
@@ -649,8 +644,8 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     // special case: current versions roll over, and we have to check their currency
     try {
       String url = ciList.get(id);
-      JsonObject json = JsonTrackingParser.fetchJson(Utilities.pathURL(url, "package.manifest.json"));
+      JsonObject json = JsonParser.parseObjectFromUrl(Utilities.pathURL(url, "package.manifest.json"));
-      String currDate = JsonUtilities.str(json, "date");
+      String currDate = json.asString("date");
       String packDate = p.date();
       if (!currDate.equals(packDate)) {
         return null; // nup, we need a new copy
@@ -678,17 +673,17 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     HTTPResult res = http.get("https://build.fhir.org/ig/qas.json?nocache=" + System.currentTimeMillis());
     res.checkThrowException();
 
-    buildInfo = (JsonArray) new com.google.gson.JsonParser().parse(TextFile.bytesToString(res.getContent()));
+    buildInfo = (JsonArray) JsonParser.parse(TextFile.bytesToString(res.getContent()));
 
     List<BuildRecord> builds = new ArrayList<>();
 
     for (JsonElement n : buildInfo) {
       JsonObject o = (JsonObject) n;
-      if (o.has("url") && o.has("package-id") && o.get("package-id").getAsString().contains(".")) {
+      if (o.has("url") && o.has("package-id") && o.asString("package-id").contains(".")) {
-        String u = o.get("url").getAsString();
+        String u = o.asString("url");
         if (u.contains("/ImplementationGuide/"))
           u = u.substring(0, u.indexOf("/ImplementationGuide/"));
-        builds.add(new BuildRecord(u, o.get("package-id").getAsString(), getRepo(o.get("repo").getAsString()), readDate(o.get("date").getAsString())));
+        builds.add(new BuildRecord(u, o.asString("package-id"), getRepo(o.asString("repo")), readDate(o.asString("date"))));
       }
     }
     Collections.sort(builds, new BuildRecordSorter());
@@ -735,7 +730,7 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
     String aurl = pu;
     JsonObject json;
     try {
-      json = JsonTrackingParser.fetchJson(pu);
+      json = JsonParser.parseObjectFromUrl(pu);
     } catch (Exception e) {
       String pv = Utilities.pathURL(url, v, "package.tgz");
       try {
@@ -746,13 +741,12 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
         throw new FHIRException("Error fetching package directly (" + pv + "), or fetching package list for " + id + " from " + pu + ": " + e1.getMessage(), e1);
       }
     }
-    if (!id.equals(JsonUtilities.str(json, "package-id")))
+    if (!id.equals(json.asString("package-id")))
-      throw new FHIRException("Package ids do not match in " + pu + ": " + id + " vs " + JsonUtilities.str(json, "package-id"));
+      throw new FHIRException("Package ids do not match in " + pu + ": " + id + " vs " + json.asString("package-id"));
-    for (JsonElement e : json.getAsJsonArray("list")) {
+    for (JsonObject vo : json.getJsonObjects("list")) {
-      JsonObject vo = (JsonObject) e;
+      if (v.equals(vo.asString("version"))) {
-      if (v.equals(JsonUtilities.str(vo, "version"))) {
+        aurl = Utilities.pathURL(vo.asString("path"), "package.tgz");
-        aurl = Utilities.pathURL(JsonUtilities.str(vo, "path"), "package.tgz");
+        String u = Utilities.pathURL(vo.asString("path"), "package.tgz");
-        String u = Utilities.pathURL(JsonUtilities.str(vo, "path"), "package.tgz");
         return new InputStreamWithSrc(fetchFromUrlSpecific(u, true), u, v);
       }
     }
@@ -776,13 +770,12 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
       throw new FHIRException("Unable to resolve package id " + id);
     }
     String pu = Utilities.pathURL(url, "package-list.json");
-    JsonObject json = JsonTrackingParser.fetchJson(pu);
+    JsonObject json = JsonParser.parseObjectFromUrl(pu);
-    if (!id.equals(JsonUtilities.str(json, "package-id")))
+    if (!id.equals(json.asString("package-id")))
-      throw new FHIRException("Package ids do not match in " + pu + ": " + id + " vs " + JsonUtilities.str(json, "package-id"));
+      throw new FHIRException("Package ids do not match in " + pu + ": " + id + " vs " + json.asString("package-id"));
-    for (JsonElement e : json.getAsJsonArray("list")) {
+    for (JsonObject vo : json.getJsonObjects("list")) {
-      JsonObject vo = (JsonObject) e;
+      if (vo.asBoolean("current")) {
-      if (JsonUtilities.bool(vo, "current")) {
+        return vo.asString("version");
-        return JsonUtilities.str(vo, "version");
       }
     }
 

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/NpmPackage.java

@@ -66,15 +66,13 @@ import org.hl7.fhir.utilities.SimpleHTTPClient;
 import org.hl7.fhir.utilities.SimpleHTTPClient.HTTPResult;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonElement;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.model.JsonProperty;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.npm.PackageGenerator.PackageType;
 
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-
 /**
  * info and loader for a package 
  * 
@@ -111,13 +109,13 @@ public class NpmPackage {
     
     public PackageResourceInformation(String root, JsonObject fi) throws IOException {
       super();
-      id = JsonUtilities.str(fi, "id");
+      id = fi.asString("id");
-      resourceType = JsonUtilities.str(fi, "resourceType");
+      resourceType = fi.asString("resourceType");
-      url = JsonUtilities.str(fi, "url");
+      url = fi.asString("url");
-      version = JsonUtilities.str(fi, "version");
+      version = fi.asString("version");
-      filename = Utilities.path(root, JsonUtilities.str(fi, "filename"));
+      filename = Utilities.path(root, fi.asString("filename"));
-      supplements = JsonUtilities.str(fi, "supplements");
+      supplements = fi.asString("supplements");
-      stype = JsonUtilities.str(fi, "type");
+      stype = fi.asString("type");
     }
     public String getId() {
       return id;
@@ -146,8 +144,8 @@ public class NpmPackage {
 
     @Override
     public int compare(JsonObject o0, JsonObject o1) {
-      String v0 = JsonUtilities.str(o0, "version"); 
+      String v0 = o0.asString("version"); 
-      String v1 = JsonUtilities.str(o1, "version"); 
+      String v1 = o1.asString("version"); 
       return v0.compareTo(v1);
     }
   }
@@ -181,14 +179,13 @@ public class NpmPackage {
     }
 
     public boolean readIndex(JsonObject index) {
-      if (!index.has("index-version") || (index.get("index-version").getAsInt() != 1)) {
+      if (!index.has("index-version") || (index.asInteger("index-version") != 1)) {
         return false;
       }
       this.index = index;
-      for (JsonElement e : index.getAsJsonArray("files")) {
+      for (JsonObject file : index.getJsonObjects("files")) {
-        JsonObject file = (JsonObject) e;
+        String type = file.asString("resourceType");
-        String type = JsonUtilities.str(file, "resourceType");
+        String name = file.asString("filename");
-        String name = JsonUtilities.str(file, "filename");
         if (!types.containsKey(type))
           types.put(type, new ArrayList<>());
         types.get(type).add(name);
@@ -301,7 +298,7 @@ public class NpmPackage {
   }
 
   public void loadFiles(String path, File source, String... exemptions) throws FileNotFoundException, IOException {
-    this.npm = (JsonObject) new com.google.gson.JsonParser().parse(TextFile.fileToString(Utilities.path(path, "package", "package.json")));
+    this.npm = JsonParser.parseObject(TextFile.fileToString(Utilities.path(path, "package", "package.json")));
     this.path = path;
     
     File dir = new File(path);
@@ -318,7 +315,7 @@ public class NpmPackage {
           File ij = new File(Utilities.path(f.getAbsolutePath(), ".index.json"));
           if (ij.exists()) {
             try {
-              if (!folder.readIndex(JsonTrackingParser.parseJson(ij))) {
+              if (!folder.readIndex(JsonParser.parseObject(ij))) {
                 indexFolder(folder.getName(), folder);
               }
             } catch (Exception e) {
@@ -353,7 +350,7 @@ public class NpmPackage {
         File ij = new File(Utilities.path(f.getAbsolutePath(), ".index.json"));
         if (ij.exists()) {
           try {
-            if (!folder.readIndex(JsonTrackingParser.parseJson(ij))) {
+            if (!folder.readIndex(JsonParser.parseObject(ij))) {
               indexFolder(folder.getName(), folder);
             }
           } catch (Exception e) {
@@ -374,7 +371,7 @@ public class NpmPackage {
     if (!res.folders.get("package").hasFile("package.json") && defType != null) {
       TextFile.stringToFile("{ \"type\" : \""+defType.getCode()+"\"}", Utilities.path(res.folders.get("package").folder.getAbsolutePath(), "package.json"));
     }
-    res.npm = (JsonObject) new com.google.gson.JsonParser().parse(new String(res.folders.get("package").fetchFile("package.json")));
+    res.npm = JsonParser.parseObject(new String(res.folders.get("package").fetchFile("package.json")));
     return res;
   }
 
@@ -439,7 +436,7 @@ public class NpmPackage {
       }
     } 
     try {
-      npm = JsonTrackingParser.parseJson(folders.get("package").fetchFile("package.json"));
+      npm = JsonParser.parseObject(folders.get("package").fetchFile("package.json"));
     } catch (Exception e) {
       throw new IOException("Error parsing "+(desc == null ? "" : desc+"#")+"package/package.json: "+e.getMessage(), e);
     }
@@ -482,7 +479,7 @@ public class NpmPackage {
     }
     String json = indexer.build();
     try {
-      folder.readIndex(JsonTrackingParser.parseJson(json));
+      folder.readIndex(JsonParser.parseObject(json));
       if (folder.folder != null) {
         TextFile.stringToFile(json, Utilities.path(folder.folder.getAbsolutePath(), ".index.json"));
       }
@@ -520,7 +517,7 @@ public class NpmPackage {
     }
     zip.close();         
     try {
-      res.npm = JsonTrackingParser.parseJson(res.folders.get("package").fetchFile("package.json"));
+      res.npm = JsonParser.parseObject(res.folders.get("package").fetchFile("package.json"));
     } catch (Exception e) {
       throw new IOException("Error parsing "+(desc == null ? "" : desc+"#")+"package/package.json: "+e.getMessage(), e);
     }
@@ -561,9 +558,8 @@ public class NpmPackage {
     List<PackageResourceInformation> res = new ArrayList<PackageResourceInformation>();
     for (NpmPackageFolder folder : folders.values()) {
       if (folder.index != null) {
-        for (JsonElement e : folder.index.getAsJsonArray("files")) {
+        for (JsonObject fi : folder.index.getJsonObjects("files")) {
-          JsonObject fi = e.getAsJsonObject();
+          if (Utilities.existsInList(fi.asString("resourceType"), types)) {
-          if (Utilities.existsInList(JsonUtilities.str(fi, "resourceType"), types)) {
             res.add(new PackageResourceInformation(folder.folder == null ? "@"+folder.getName() : folder.folder.getAbsolutePath(), fi));
           }
         }
@@ -634,21 +630,20 @@ public class NpmPackage {
   public InputStream loadByCanonicalVersion(String folder, String canonical, String version) throws IOException {
     NpmPackageFolder f = folders.get(folder);
     List<JsonObject> matches = new ArrayList<>();
-    for (JsonElement e : f.index.getAsJsonArray("files")) {
+    for (JsonObject file : f.index.getJsonObjects("files")) {
-      JsonObject file = (JsonObject) e;
+      if (canonical.equals(file.asString("url"))) {
-      if (canonical.equals(JsonUtilities.str(file, "url"))) {
+        if (version != null && version.equals(file.asString("version"))) {
-        if (version != null && version.equals(JsonUtilities.str(file, "version"))) {
+          return load("package", file.asString("filename"));
-          return load("package", JsonUtilities.str(file, "filename"));
         } else if (version == null) {
           matches.add(file);
         }
       }
       if (matches.size() > 0) {
         if (matches.size() == 1) {
-          return load("package", JsonUtilities.str(matches.get(0), "filename"));          
+          return load("package", matches.get(0).asString("filename"));          
         } else {
           Collections.sort(matches, new IndexVersionSorter());
-          return load("package", JsonUtilities.str(matches.get(matches.size()-1), "filename"));          
+          return load("package", matches.get(matches.size()-1).asString("filename"));          
         }
       }
     }
@@ -708,7 +703,7 @@ public class NpmPackage {
    * @return
    */
   public String name() {
-    return JsonUtilities.str(npm, "name");
+    return npm.asString("name");
   }
 
   /**
@@ -716,15 +711,15 @@ public class NpmPackage {
    * @return
    */
   public String id() {
-    return JsonUtilities.str(npm, "name");
+    return npm.asString("name");
   }
 
   public String date() {
-    return JsonUtilities.str(npm, "date");
+    return npm.asString("date");
   }
 
   public String canonical() {
-    return JsonUtilities.str(npm, "canonical");
+    return npm.asString("canonical");
   }
 
   /**
@@ -732,7 +727,7 @@ public class NpmPackage {
    * @return
    */
   public String version() {
-    return JsonUtilities.str(npm, "version");
+    return npm.asString("version");
   }
 
   /**
@@ -740,28 +735,28 @@ public class NpmPackage {
    * @return
    */
   public String fhirVersion() {
-    if ("hl7.fhir.core".equals(JsonUtilities.str(npm, "name")))
+    if ("hl7.fhir.core".equals(npm.asString("name")))
-      return JsonUtilities.str(npm, "version");
+      return npm.asString("version");
-    else if (JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r2.") || JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r2b.") || JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r3.") || 
+    else if (npm.asString("name").startsWith("hl7.fhir.r2.") || npm.asString("name").startsWith("hl7.fhir.r2b.") || npm.asString("name").startsWith("hl7.fhir.r3.") || 
-        JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r4.") || JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r4b.") || JsonUtilities.str(npm, "name").startsWith("hl7.fhir.r5."))
+        npm.asString("name").startsWith("hl7.fhir.r4.") || npm.asString("name").startsWith("hl7.fhir.r4b.") || npm.asString("name").startsWith("hl7.fhir.r5."))
-      return JsonUtilities.str(npm, "version");
+      return npm.asString("version");
     else {
       JsonObject dep = null;
-      if (npm.has("dependencies") && npm.get("dependencies").isJsonObject()) {
+      if (npm.hasObject("dependencies")) {
-        dep = npm.getAsJsonObject("dependencies");
+        dep = npm.getJsonObject("dependencies");
         if (dep != null) {
-          for (Entry<String, JsonElement> e : dep.entrySet()) {
+          for (JsonProperty e : dep.getProperties()) {
-            if (Utilities.existsInList(e.getKey(), "hl7.fhir.r2.core", "hl7.fhir.r2b.core", "hl7.fhir.r3.core", "hl7.fhir.r4.core"))
+            if (Utilities.existsInList(e.getName(), "hl7.fhir.r2.core", "hl7.fhir.r2b.core", "hl7.fhir.r3.core", "hl7.fhir.r4.core"))
-              return e.getValue().getAsString();
+              return e.getValue().asString();
-            if (Utilities.existsInList(e.getKey(), "hl7.fhir.core")) // while all packages are updated
+            if (Utilities.existsInList(e.getName(), "hl7.fhir.core")) // while all packages are updated
-              return e.getValue().getAsString();
+              return e.getValue().asString();
           }
         }
       }
-      if (npm.has("fhirVersions")) {
+      if (npm.hasArray("fhirVersions")) {
-        JsonElement e = npm.get("fhirVersions");
+        JsonArray e = npm.getJsonArray("fhirVersions");
-        if (e.isJsonArray() && e.getAsJsonArray().size() > 0) {
+        if (e.size() > 0) {
-          return npm.getAsJsonArray("fhirVersions").get(0).getAsString();
+          return e.getItems().get(0).asString();
         }
       }
       if (dep != null) {
@@ -789,11 +784,11 @@ public class NpmPackage {
   }
 
   public String type() {
-    return JsonUtilities.str(npm, "type");
+    return npm.asString("type");
   }
 
   public String description() {
-    return JsonUtilities.str(npm, "description");
+    return npm.asString("description");
   }
 
   public String getPath() {
@@ -803,32 +798,32 @@ public class NpmPackage {
   public List<String> dependencies() {
     List<String> res = new ArrayList<>();
     if (npm.has("dependencies")) {
-      for (Entry<String, JsonElement> e : npm.getAsJsonObject("dependencies").entrySet()) {
+      for (JsonProperty e : npm.getJsonObject("dependencies").getProperties()) {
-        res.add(e.getKey()+"#"+e.getValue().getAsString());
+        res.add(e.getName()+"#"+e.getValue().asString());
       }
     }
     return res;
   }
 
   public String homepage() {
-    return JsonUtilities.str(npm, "homepage");
+    return npm.asString("homepage");
   }
 
   public String url() {
-    return JsonUtilities.str(npm, "url");
+    return npm.asString("url");
   }
 
 
   public String title() {
-    return JsonUtilities.str(npm, "title");
+    return npm.asString("title");
   }
 
   public String toolsVersion() {
-    return JsonUtilities.str(npm, "tools-version");
+    return npm.asString("tools-version");
   }
 
   public String license() {
-    return JsonUtilities.str(npm, "license");
+    return npm.asString("license");
   }
 
   //  /**
@@ -841,20 +836,20 @@ public class NpmPackage {
   //  }
 
   public String getWebLocation() {
-    if (npm.has("url") && npm.get("url").isJsonPrimitive()) {
+    if (npm.hasPrimitive("url")) {
-      return PackageHacker.fixPackageUrl(npm.get("url").getAsString());
+      return PackageHacker.fixPackageUrl(npm.asString("url"));
     } else {
-      return JsonUtilities.str(npm, "canonical");
+      return npm.asString("canonical");
     }
   }
 
   public InputStream loadResource(String type, String id) throws IOException {
     NpmPackageFolder f = folders.get("package");
-    JsonArray files = f.index.getAsJsonArray("files");
+    JsonArray files = f.index.getJsonArray("files");
-    for (JsonElement e : files) {
+    for (JsonElement e : files.getItems()) {
       JsonObject i = (JsonObject) e;
-      if (type.equals(JsonUtilities.str(i, "resourceType")) && id.equals(JsonUtilities.str(i, "id"))) {
+      if (type.equals(i.asString("resourceType")) && id.equals(i.asString("id"))) {
-        return load("package", JsonUtilities.str(i, "filename"));
+        return load("package", i.asString("filename"));
       }
     }
     return null;
@@ -866,11 +861,11 @@ public class NpmPackage {
       f = folders.get("package/example");      
     }
     if (f != null) {
-      JsonArray files = f.index.getAsJsonArray("files");
+      JsonArray files = f.index.getJsonArray("files");
-      for (JsonElement e : files) {
+      for (JsonElement e : files.getItems()) {
         JsonObject i = (JsonObject) e;
-        if (type.equals(JsonUtilities.str(i, "resourceType")) && id.equals(JsonUtilities.str(i, "id"))) {
+        if (type.equals(i.asString("resourceType")) && id.equals(i.asString("id"))) {
-          return load("example", JsonUtilities.str(i, "filename"));
+          return load("example", i.asString("filename"));
         }
       }
     }
@@ -909,7 +904,7 @@ public class NpmPackage {
       byte[] cnt = indexer.build().getBytes(StandardCharsets.UTF_8);
       TextFile.bytesToFile(cnt, Utilities.path(dir.getAbsolutePath(), n, ".index.json"));
     }
-    byte[] cnt = TextFile.stringToBytes(new GsonBuilder().setPrettyPrinting().create().toJson(npm), false);
+    byte[] cnt = TextFile.stringToBytes(JsonParser.compose(npm, true), false);
     TextFile.bytesToFile(cnt, Utilities.path(dir.getAbsolutePath(), "package", "package.json"));
   }
   
@@ -955,7 +950,7 @@ public class NpmPackage {
       tar.write(cnt);
       tar.closeArchiveEntry();
     }
-    byte[] cnt = TextFile.stringToBytes(new GsonBuilder().setPrettyPrinting().create().toJson(npm), false);
+    byte[] cnt = TextFile.stringToBytes(JsonParser.compose(npm, true), false);
     TarArchiveEntry entry = new TarArchiveEntry("package/package.json");
     entry.setSize(cnt.length);
     tar.putArchiveEntry(entry);
@@ -981,13 +976,13 @@ public class NpmPackage {
   public String fhirVersionList() {
     if (npm.has("fhirVersions")) {
       CommaSeparatedStringBuilder b = new CommaSeparatedStringBuilder();
-      if (npm.get("fhirVersions").isJsonArray()) {
+      if (npm.hasArray("fhirVersions")) {
-        for (JsonElement n : npm.getAsJsonArray("fhirVersions")) {
+        for (String n : npm.getJsonArray("fhirVersions").asStrings()) {
-          b.append(n.getAsString());
+          b.append(n);
         }
       }
-      if (npm.get("fhirVersions").isJsonPrimitive()) {
+      if (npm.hasPrimitive("fhirVersions")) {
-        b.append(npm.get("fhirVersions").getAsString());
+        b.append(npm.asString("fhirVersions"));
       }
       return b.toString();
     } else
@@ -997,8 +992,8 @@ public class NpmPackage {
   public String dependencySummary() {
     if (npm.has("dependencies")) {
       CommaSeparatedStringBuilder b = new CommaSeparatedStringBuilder();
-      for (Entry<String, JsonElement> e : npm.getAsJsonObject("dependencies").entrySet()) {
+      for (JsonProperty e : npm.getJsonObject("dependencies").getProperties()) {
-        b.append(e.getKey()+"#"+e.getValue().getAsString());
+        b.append(e.getName()+"#"+e.getValue().asString());
       }
       return b.toString();
     } else
@@ -1080,7 +1075,7 @@ public class NpmPackage {
     folder.types.get(type).add(name);
     if ("package".equals(folderName) && "package.json".equals(name)) {
       try {
-        npm = JsonTrackingParser.parseJson(cnt);
+        npm = JsonParser.parseObject(cnt);
       } catch (IOException e) {
       }
     }
@@ -1118,11 +1113,11 @@ public class NpmPackage {
   }
 
   public boolean isCore() {
-    return Utilities.existsInList(JsonUtilities.str(npm, "type"), "fhir.core", "Core");
+    return Utilities.existsInList(npm.asString("type"), "fhir.core", "Core");
   }
 
   public boolean isTx() {
-    return JsonUtilities.str(npm, "name").startsWith("hl7.terminology");
+    return npm.asString("name").startsWith("hl7.terminology");
   }
 
   public boolean hasCanonical(String url) {
@@ -1133,10 +1128,9 @@ public class NpmPackage {
     String v = url.contains("|") ?  url.substring(url.indexOf("|")+1) : null;
     NpmPackageFolder folder = folders.get("package");
     if (folder != null) {
-      for (JsonElement e : folder.index.getAsJsonArray("files")) {
+      for (JsonObject o : folder.index.getJsonObjects("files")) {
-        JsonObject o = (JsonObject) e;
+        if (u.equals(o.asString("url"))) {
-        if (u.equals(JsonUtilities.str(o, "url"))) {
+          if (v == null || v.equals(o.asString("version"))) {
-          if (v == null || v.equals(JsonUtilities.str(o, "version"))) {
             return true;
           }
         }
@@ -1154,7 +1148,7 @@ public class NpmPackage {
     if (Utilities.existsInList(name(), "fhir.test.data.r2", "fhir.test.data.r3", "fhir.test.data.r4", "fhir.tx.support.r2", "fhir.tx.support.r3", "fhir.tx.support.r4", "us.nlm.vsac")) {
       return true;
     }
-    if (JsonUtilities.bool(npm, "lazy-load")) {
+    if (npm.asBoolean("lazy-load")) {
       return true;
     }
     if (!hasFile("other", "spec.internals")) {
@@ -1164,7 +1158,7 @@ public class NpmPackage {
   }
 
   public boolean isNotForPublication() {
-    return JsonUtilities.bool(npm, "notForPublication");
+    return npm.asBoolean("notForPublication");
  }
 
   public InputStream load(PackageResourceInformation p) throws FileNotFoundException {

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/NpmPackageIndexBuilder.java

@@ -6,11 +6,9 @@ import java.io.IOException;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-
+import org.hl7.fhir.utilities.json.model.JsonObject;
-import com.google.gson.GsonBuilder;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
 
 /**
  * This class builds the .index.json for a package 
@@ -25,7 +23,7 @@ public class NpmPackageIndexBuilder {
   
   public void start() {
     index = new JsonObject();
-    index.addProperty("index-version", 1);
+    index.add("index-version", 1);
     files = new JsonArray();
     index.add("files", files);
   }
@@ -33,30 +31,30 @@ public class NpmPackageIndexBuilder {
   public boolean seeFile(String name, byte[] content) {
     if (name.endsWith(".json")) {
       try {
-        JsonObject json = JsonTrackingParser.parseJson(content);
+        JsonObject json = JsonParser.parseObject(content);
         if (json.has("resourceType")) {
           // ok we treat it as a resource
           JsonObject fi = new JsonObject();
           files.add(fi);
-          fi.addProperty("filename", name);
+          fi.add("filename", name);
-          fi.addProperty("resourceType", json.get("resourceType").getAsString()); 
+          fi.add("resourceType", json.asString("resourceType")); 
-          if (json.has("id") && json.get("id").isJsonPrimitive()) {
+          if (json.hasPrimitive("id")) {
-            fi.addProperty("id", json.get("id").getAsString());
+            fi.add("id", json.asString("id"));
           }
-          if (json.has("url") && json.get("url").isJsonPrimitive()) {
+          if (json.hasPrimitive("url")) {
-            fi.addProperty("url", json.get("url").getAsString());
+            fi.add("url", json.asString("url"));
           }
-          if (json.has("version") && json.get("version").isJsonPrimitive()) {
+          if (json.hasPrimitive("version")) {
-            fi.addProperty("version", json.get("version").getAsString());
+            fi.add("version", json.asString("version"));
           }
-          if (json.has("kind") && json.get("kind").isJsonPrimitive()) {
+          if (json.hasPrimitive("kind")) {
-            fi.addProperty("kind", json.get("kind").getAsString());
+            fi.add("kind", json.asString("kind"));
           }
-          if (json.has("type") && json.get("type").isJsonPrimitive()) {
+          if (json.hasPrimitive("type")) {
-            fi.addProperty("type", json.get("type").getAsString());
+            fi.add("type", json.asString("type"));
           }
-          if (json.has("supplements") && json.get("supplements").isJsonPrimitive()) {
+          if (json.hasPrimitive("supplements")) {
-            fi.addProperty("supplements", json.get("supplements").getAsString());
+            fi.add("supplements", json.asString("supplements"));
           }
         }
       } catch (Exception e) {
@@ -70,7 +68,7 @@ public class NpmPackageIndexBuilder {
   }
   
   public String build() {
-    String res = new GsonBuilder().setPrettyPrinting().create().toJson(index);
+    String res = JsonParser.compose(index, true);
     index = null;
     files = null;
     return res;

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/PackageClient.java

@@ -17,12 +17,10 @@ import org.hl7.fhir.utilities.SimpleHTTPClient.HTTPResult;
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.VersionUtilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.model.JsonObject;
-
+import org.hl7.fhir.utilities.json.model.JsonProperty;
-import com.google.gson.JsonArray;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
 
 public class PackageClient {
 
@@ -81,21 +79,21 @@ public class PackageClient {
     JsonObject json;
     try {
       json = fetchJson(Utilities.pathURL(address, id));
-      JsonObject versions = json.getAsJsonObject("versions");
+      JsonObject versions = json.getJsonObject("versions");
       boolean hasDates = true;
       if (versions != null) {
-        for (String v : versions.keySet()) {
+        for (JsonProperty v : versions.getProperties()) {
-          JsonObject obj = versions.getAsJsonObject(v);
+          JsonObject obj = versions.getJsonObject(v.getName());
-          Instant d = obj.has("date") ? JsonUtilities.parseDate(obj, "date") : null;
+          Instant d = obj.hasString("date") ? obj.asDate("date") : null;
           if (d == null) {
             hasDates = false;
           }
-          res.add(new PackageInfo(JsonUtilities.str(obj, "Name", "name"),
+          res.add(new PackageInfo(obj.asString("Name", "name"),
-            JsonUtilities.str(obj, "Version", "version"),
+            obj.asString("Version", "version"),
-            JsonUtilities.str(obj, "FhirVersion", "fhirVersion"),
+            obj.asString("FhirVersion", "fhirVersion"),
-            JsonUtilities.str(obj, "Description", "description"),
+            obj.asString("Description", "description"),
-            JsonUtilities.str(obj, "url"),
+            obj.asString("url"),
-            JsonUtilities.str(obj, "canonical"),
+            obj.asString("canonical"),
             address, d));
         }
       }
@@ -127,18 +125,17 @@ public class PackageClient {
     try {
       JsonArray json = fetchJsonArray(Utilities.pathURL(address, "catalog?")+params.toString());
       boolean hasDates = true;
-      for (JsonElement e : json) {
+      for (JsonObject obj : json.asJsonObjects()) {
-        JsonObject obj = (JsonObject) e;
+        Instant d = obj.has("date") ? obj.asDate("date") : null;
-        Instant d = obj.has("date") ? JsonUtilities.parseDate(obj, "date") : null;
         if (d == null) {
           hasDates = false;
         }
-        res.add(new PackageInfo(JsonUtilities.str(obj, "Name", "name"),
+        res.add(new PackageInfo(obj.asString("Name", "name"),
-          JsonUtilities.str(obj, "Version", "version"),
+          obj.asString("Version", "version"),
-          JsonUtilities.str(obj, "FhirVersion", "fhirVersion"),
+          obj.asString("FhirVersion", "fhirVersion"),
-          JsonUtilities.str(obj, "Description", "description"),
+          obj.asString("Description", "description"),
-          JsonUtilities.str(obj, "url"),
+          obj.asString("url"),
-          JsonUtilities.str(obj, "canonical"),
+          obj.asString("canonical"),
           address, d));
       }
       if (hasDates) {
@@ -165,13 +162,13 @@ public class PackageClient {
   private JsonObject fetchJson(String source) throws IOException {
     String src = TextFile.streamToString(fetchUrl(source, "application/json"));
     //System.out.println(src);
-    return (JsonObject) new com.google.gson.JsonParser().parse(src);
+    return JsonParser.parseObject(src);
   }
   
   private JsonArray fetchJsonArray(String source) throws IOException {
     String src = TextFile.streamToString(fetchUrl(source, "application/json"));
     //System.out.println(src);
-    return (JsonArray) new com.google.gson.JsonParser().parse(src);
+    return (JsonArray) JsonParser.parse(src);
   }
 
   public String url(String id, String v) {
@@ -209,11 +206,11 @@ public class PackageClient {
   }
 
   protected PackageInfo getPackageInfoFromJSON(JsonObject o, String name, String canonical, String fhirVersion) {
-      String id = JsonUtilities.str(o, "npm-name");
+      String id = o.asString("npm-name");
-      String pname = JsonUtilities.str(o, "name");
+      String pname = o.asString("name");
-      String pcanonical = JsonUtilities.str(o, "canonical");
+      String pcanonical = o.asString("canonical");
-      String description = JsonUtilities.str(o, "description");
+      String description = o.asString("description");
-      Instant d = o.has("date") ? JsonUtilities.parseDate(o, "date") : null;
+      Instant d = o.has("date") ? o.asDate("date") : null;
       boolean ok = true;
       if (ok && !Utilities.noString(name)) {
         ok = (pname != null && pname.contains(name)) || (description != null && description.contains(name)) || (id != null && id.contains(name));
@@ -227,15 +224,15 @@ public class PackageClient {
 
       if (ok) {
         // if we can find something...
-        for (JsonObject e : JsonUtilities.objects(o, "editions")) {
+        for (JsonObject e : o.getJsonObjects("editions")) {
-          if (fhirVersion == null || fhirVersion.equals(JsonUtilities.str(e, "fhir-version"))) {
+          if (fhirVersion == null || fhirVersion.equals(e.asString("fhir-version"))) {
-            String v = JsonUtilities.str(e, "ig-version");
+            String v = e.asString("ig-version");
             if (version == null || VersionUtilities.isThisOrLater(version, v)) {
               version = v;
-              fVersion = e.getAsJsonArray("fhir-version").get(0).getAsString();
+              fVersion = e.getJsonArray("fhir-version").get(0).asString();
-              url = JsonUtilities.str(e, "url");
+              url = e.asString("url");
 
-              String npmPackage = JsonUtilities.str(e, "package");
+              String npmPackage = e.asString("package");
               if (npmPackage != null && id == null) {
                 id = npmPackage.substring(0, npmPackage.indexOf("#"));
               }
@@ -248,8 +245,8 @@ public class PackageClient {
   
   public List<PackageInfo> listFromRegistry(String name, String canonical, String fhirVersion) throws IOException {
     List<PackageInfo> result = new ArrayList<>();
-    JsonObject packages = JsonTrackingParser.fetchJson("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json?nocache=" + System.currentTimeMillis());
+    JsonObject packages = JsonParser.parseObjectFromUrl("https://raw.githubusercontent.com/FHIR/ig-registry/master/fhir-ig-list.json?nocache=" + System.currentTimeMillis());
-    for (JsonObject o : JsonUtilities.objects(packages, "guides")) {
+    for (JsonObject o : packages.getJsonObjects("guides")) {
       if (o.has("canonical")) {
       final PackageInfo packageInfo = getPackageInfoFromJSON(o, name, canonical, fhirVersion);
         if (packageInfo.getVersion() != null) {
@@ -265,9 +262,8 @@ public class PackageClient {
     params.append("dependency="+id.replace("#", "|"));
     try {
       JsonArray json = fetchJsonArray(Utilities.pathURL(address, "catalog?")+params.toString());
-      for (JsonElement e : json) {
+      for (JsonObject obj : json.asJsonObjects()) {
-        JsonObject obj = (JsonObject) e;
+        list.add(obj.asString("Name", "name"));
-        list.add(JsonUtilities.str(obj, "Name", "name"));
       }
     } catch (IOException e1) {
     }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/PackageGenerator.java

@@ -39,14 +39,9 @@ import java.util.List;
 
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-
+import org.hl7.fhir.utilities.json.model.JsonArray;
-import com.google.gson.Gson;
+import org.hl7.fhir.utilities.json.model.JsonObject;
-import com.google.gson.GsonBuilder;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
-import com.google.gson.JsonPrimitive;
-import com.google.gson.JsonSyntaxException;
 
 public class PackageGenerator {
 
@@ -94,11 +89,10 @@ public class PackageGenerator {
     object = new JsonObject();
   }
   
-  public PackageGenerator(OutputStream stream, InputStream template) throws JsonSyntaxException, IOException {
+  public PackageGenerator(OutputStream stream, InputStream template) throws IOException {
     super();
     this.stream = stream;
-    JsonParser parser = new com.google.gson.JsonParser();
+    object = JsonParser.parseObject(TextFile.streamToString(template));
-    object = parser.parse(TextFile.streamToString(template)).getAsJsonObject();
 
   }
 
@@ -107,8 +101,7 @@ public class PackageGenerator {
   }
 
   public void commit() throws IOException {
-    Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    String json = JsonParser.compose(object, true);
-    String json = gson.toJson(object);
     OutputStreamWriter sw = new OutputStreamWriter(stream, "UTF-8");
     sw.write('\ufeff');  // Unicode BOM, translates to UTF-8 with the configured outputstreamwriter
     sw.write(json);
@@ -118,17 +111,17 @@ public class PackageGenerator {
   
   public PackageGenerator name(String value) {
     // NOTE: I removed a prefix of "@fhir/" here. What was this for? -JA
-    object.addProperty("name", value);
+    object.add("name", value);
     return this;
   }
    
   public PackageGenerator version(String value) {
-    object.addProperty("version", value);
+    object.add("version", value);
     return this;
   }
 
   public PackageGenerator toolsVersion(int value) {
-    object.addProperty("tools-version", value);
+    object.add("tools-version", value);
     return this;
   }
 
@@ -142,44 +135,44 @@ public class PackageGenerator {
   }
   
   public PackageGenerator description(String value) {
-    object.addProperty("description", value);
+    object.add("description", value);
     return this;
   }
   
   public PackageGenerator license(String value) {
-    object.addProperty("license", value);
+    object.add("license", value);
     return this;
   }
   
   public PackageGenerator homepage(String value) {
-    object.addProperty("homepage", value);
+    object.add("homepage", value);
     return this;            
   }
   
   public PackageGenerator bugs(String value) {
-    object.addProperty("bugs", value);
+    object.add("bugs", value);
     return this;            
   }
   
   public PackageGenerator author(String name, String email, String url) {
     JsonObject person = new JsonObject();
-    person.addProperty("name", name);
+    person.add("name", name);
     if (!Utilities.noString(email))
-      person.addProperty("email", email);
+      person.add("email", email);
     if (!Utilities.noString(url))
-      person.addProperty("url", url);
+      person.add("url", url);
     object.add("author", person);
     return this;            
   }
   
   public PackageGenerator contributor(String name, String email, String url) {
     JsonObject person = new JsonObject();
-    person.addProperty("name", name);
+    person.add("name", name);
     if (!Utilities.noString(email))
-      person.addProperty("email", email);
+      person.add("email", email);
     if (!Utilities.noString(url))
-      person.addProperty("url", url);
+      person.add("url", url);
-    JsonArray c = object.getAsJsonArray("contributors");
+    JsonArray c = object.getJsonArray("contributors");
     if (c == null) {
       c = new JsonArray();
       object.add("contributors", c);
@@ -189,27 +182,23 @@ public class PackageGenerator {
   }
   
   public PackageGenerator dependency(String name, String version) {
-    JsonObject dep = object.getAsJsonObject("dependencies");
+    JsonObject dep = object.getJsonObject("dependencies");
     if (dep == null) {
       dep = new JsonObject();
       object.add("dependencies", dep);
     }
-    dep.addProperty(name, version);
+    dep.add(name, version);
     return this;
   }
   
   public PackageGenerator file(String name) {
-    JsonArray files = object.getAsJsonArray("files");
+    JsonArray files = object.forceArray("files");
-    if (files == null) {
+    files.add(name);
-      files = new JsonArray();
-      object.add("files", files);
-    }
-    files.add(new JsonPrimitive(name));
     return this;
   }
 
   public PackageGenerator kind(PackageType kind) {
-    object.addProperty("type", kind.getCode());
+    object.add("type", kind.getCode());
     return this;     
   }
   

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/PackageHacker.java

@@ -12,10 +12,11 @@ import java.util.Map;
 
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
+import org.hl7.fhir.utilities.json.model.JsonArray;
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
+
 
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
 
 /**
  * intenral use only - set the file name to edit in main(), and fill out the edit routine
@@ -74,14 +75,14 @@ public class PackageHacker {
   }
 
   private String nice(JsonObject json) {
-    return new GsonBuilder().setPrettyPrinting().create().toJson(json);
+    return JsonParser.compose(json, true);
   }
 
   private void change(JsonObject npm) throws FileNotFoundException, IOException {
 //    fixVersions(npm);
 //    npm.remove("notForPublication");
     npm.remove("url");
-    npm.addProperty("url", "https://hl7chile.cl/fhir/ig/CoreCL/1.7.0");
+    npm.add("url", "https://hl7chile.cl/fhir/ig/CoreCL/1.7.0");
 //    npm.remove("name");
 //    npm.addProperty("name", "hl7.fhir.uv.smart-app-launch");
 //    npm.remove("canonical");
@@ -128,7 +129,7 @@ public class PackageHacker {
 
   private void setProperty(JsonObject npm, String name, String value) {
     npm.remove("homepage");
-    npm.addProperty("homepage", "http://hl7.org/fhir");    
+    npm.add("homepage", "http://hl7.org/fhir");    
   }
 
   private void fixNames(Map<String, byte[]> content) {

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/PackageScanner.java

@@ -9,10 +9,9 @@ import java.util.Set;
 
 import org.hl7.fhir.utilities.TextFile;
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 
-import com.google.gson.JsonObject;
 
 public class PackageScanner {
 
@@ -63,7 +62,7 @@ public class PackageScanner {
             } catch (Exception e) {
               fv = "--";
             }
-            output.add(pck.name()+"\t"+pck.version()+"\t"+pck.canonical()+"\t"+fv+'\t'+pck.fhirVersionList()+'\t'+JsonUtilities.str(json, "kind")+'\t'+JsonUtilities.str(json, "type")+'\t'+JsonTrackingParser.writeDense(json));          } catch (Exception e) {
+            output.add(pck.name()+"\t"+pck.version()+"\t"+pck.canonical()+"\t"+fv+'\t'+pck.fhirVersionList()+'\t'+json.asString("kind")+'\t'+json.asString("type")+'\t'+JsonParser.compose(json));          } catch (Exception e) {
             System.out.println("Error acessing "+pi.getId()+"#"+piv.getVersion()+": "+e.getMessage());
             e.printStackTrace();
           }

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/ResourceRenamer.java

@@ -1,13 +1,13 @@
 package org.hl7.fhir.utilities.npm;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 
 import org.hl7.fhir.utilities.Utilities;
-import org.hl7.fhir.utilities.json.JsonTrackingParser;
+import org.hl7.fhir.utilities.json.model.JsonObject;
-import org.hl7.fhir.utilities.json.JsonUtilities;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 
-import com.google.gson.JsonObject;
 
 public class ResourceRenamer {
 
@@ -24,13 +24,13 @@ public class ResourceRenamer {
   }
 
   private void unbundle(File f) throws IOException {
-    JsonObject j = JsonTrackingParser.parseJson(f);
+    JsonObject j = JsonParser.parseObject(f);
-    for (JsonObject e : JsonUtilities.objects(j, "entry")) {
+    for (JsonObject e : j.getJsonObjects("entry")) {
-      JsonObject r = e.getAsJsonObject("resource");
+      JsonObject r = e.getJsonObject("resource");
-      String rt = r.get("resourceType").getAsString();
+      String rt = r.asString("resourceType");
-      String id = r.get("id").getAsString();
+      String id = r.asString("id");
       String nn = Utilities.path(Utilities.getDirectoryForFile(f.getAbsolutePath()), rt+"-"+id+".json");
-      JsonTrackingParser.write(r, new File(nn), true); 
+      JsonParser.compose(r, new FileOutputStream(nn), true); 
     } 
   }
 
@@ -39,9 +39,9 @@ public class ResourceRenamer {
     for (File f : dir.listFiles()) {
       if (f.getName().endsWith(".json")) {
         try {
-          JsonObject j = JsonTrackingParser.parseJson(f);
+          JsonObject j = JsonParser.parseObject(f);
-          String rt = j.get("resourceType").getAsString();
+          String rt = j.asString("resourceType");
-          String id = j.get("id").getAsString();
+          String id = j.asString("id");
           String nn = Utilities.path(Utilities.getDirectoryForFile(f.getAbsolutePath()), rt+"-"+id+".json");
           File nf = new File(nn);
           if (!nn.equals(f.getAbsolutePath())) {

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/DateTimeUtilTests.java

@@ -1,6 +1,12 @@
 package org.hl7.fhir.utilities;
 
-import ca.uhn.fhir.model.api.TemporalPrecisionEnum;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.stream.Stream;
+
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Disabled;
@@ -8,12 +14,7 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
-import java.util.Date;
+import ca.uhn.fhir.model.api.TemporalPrecisionEnum;
-import java.util.Locale;
-import java.util.TimeZone;
-import java.util.stream.Stream;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class DateTimeUtilTests {
 

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/DurationUtilTest.java

@@ -1,18 +1,19 @@
 package org.hl7.fhir.utilities;
 
-import org.junit.jupiter.params.ParameterizedTest;
+import static org.junit.jupiter.api.Assertions.assertEquals;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-import org.xml.sax.SAXException;
 
-import javax.xml.parsers.ParserConfigurationException;
 import java.io.IOException;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Stream;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import javax.xml.parsers.ParserConfigurationException;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.xml.sax.SAXException;
 
 
 public class DurationUtilTest {

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/FileFormatTest.java

@@ -1,6 +1,8 @@
 package org.hl7.fhir.utilities;
 
-import org.junit.jupiter.api.Test;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -8,9 +10,7 @@ import java.io.PrintStream;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 
-import static org.hamcrest.CoreMatchers.containsString;
+import org.junit.jupiter.api.Test;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.assertEquals;
 
 public class FileFormatTest {
   @Test

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/SimpleHTTPClientTest.java

@@ -1,11 +1,10 @@
 package org.hl7.fhir.utilities;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import org.junit.jupiter.api.Test;
 
 public class SimpleHTTPClientTest {
   @Test

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/UtilitiesTest.java

@@ -1,9 +1,6 @@
 package org.hl7.fhir.utilities;
 
-import org.apache.commons.lang3.SystemUtils;
+import static org.junit.jupiter.api.Assertions.assertTrue;
-import org.junit.jupiter.api.Assertions;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
 
 import java.io.File;
 import java.io.IOException;
@@ -11,7 +8,10 @@ import java.nio.file.Paths;
 import java.text.MessageFormat;
 import java.util.Random;
 
-import static org.junit.jupiter.api.Assertions.*;
+import org.apache.commons.lang3.SystemUtils;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
 
 class UtilitiesTest {
 

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/VersionUtilitiesTest.java

@@ -1,8 +1,9 @@
 package org.hl7.fhir.utilities;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 public class VersionUtilitiesTest {
 

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/i18n/I18nBaseTest.java

@@ -1,10 +1,8 @@
 package org.hl7.fhir.utilities.i18n;
 
-import com.ibm.icu.text.PluralRules;
+import static org.hamcrest.CoreMatchers.containsString;
-import org.junit.jupiter.api.Assertions;
+import static org.hamcrest.MatcherAssert.assertThat;
-import org.junit.jupiter.api.Disabled;
+import static org.junit.jupiter.api.Assertions.assertFalse;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -12,12 +10,13 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.ResourceBundle;
 
-import static org.hamcrest.CoreMatchers.containsString;
+import org.junit.jupiter.api.Assertions;
-import static org.hamcrest.MatcherAssert.assertThat;
+import org.junit.jupiter.api.DisplayName;
-import static org.junit.jupiter.api.Assertions.assertFalse;
+import org.junit.jupiter.api.Test;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class I18nBaseTest {
 

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/i18n/ICU4JTests.java

@@ -1,14 +1,15 @@
 package org.hl7.fhir.utilities.i18n;
 
-import com.ibm.icu.text.PluralRules;
+import static org.junit.jupiter.api.Assertions.assertEquals;
-import org.junit.jupiter.api.Test;
 
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Set;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+import com.ibm.icu.text.PluralRules;
 
 public class ICU4JTests {
 

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/json/JsonParserTests.java

@@ -26,7 +26,7 @@ public class JsonParserTests {
   public void testComments2() throws IOException, JsonException {
     JsonObject obj = JsonParser.parseObject("{\n  // some comment \n  \"n1\" : \"v1\"\n}\n", true);
     Assertions.assertEquals(0, obj.getComments().size());
-    JsonString c = obj.getString("n1");
+    JsonString c = obj.getJsonString("n1");
     Assertions.assertEquals(1, c.getComments().size());
     Assertions.assertEquals("some comment", c.getComments().get(0));
     Assertions.assertEquals("{\"n1\":\"v1\"}", JsonParser.compose(obj, false));
@@ -38,7 +38,7 @@ public class JsonParserTests {
     JsonObject obj = JsonParser.parseObject("// some comment\n{\n  \"n1\" : \"v1\"\n}\n", true);
     Assertions.assertEquals(1, obj.getComments().size());
     Assertions.assertEquals("some comment", obj.getComments().get(0));
-    JsonString c = obj.getString("n1");
+    JsonString c = obj.getJsonString("n1");
     Assertions.assertEquals(0, c.getComments().size());
     Assertions.assertEquals("{\"n1\":\"v1\"}", JsonParser.compose(obj, false));
     Assertions.assertEquals("// some comment\n{\n  \"n1\" : \"v1\"\n}\n", JsonParser.compose(obj, true));

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/npm/PackageClientTest.java

@@ -1,20 +1,16 @@
 package org.hl7.fhir.utilities.npm;
 
-import com.google.gson.Gson;
+
-import com.google.gson.JsonObject;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.net.URISyntaxException;
+
+import org.hl7.fhir.utilities.json.model.JsonObject;
+import org.hl7.fhir.utilities.json.parser.JsonParser;
 import org.hl7.fhir.utilities.tests.ResourceLoaderTests;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import java.io.BufferedReader;
-import java.io.InputStreamReader;
-import java.net.URISyntaxException;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 public class PackageClientTest implements ResourceLoaderTests {
 
   PackageClient packageClient = new PackageClient(PackageClient.PRIMARY_SERVER);
@@ -32,7 +28,7 @@ public class PackageClientTest implements ResourceLoaderTests {
   @Test
   @DisplayName("test getting package from JSON works")
   public void getPackageInfoFromJSONTest() throws java.io.IOException, URISyntaxException {
-    final JsonObject jsonObject = new Gson().fromJson(new InputStreamReader(getResourceAsInputStream("npm","PackageClient-baseTestCase.json")), JsonObject.class);
+    final JsonObject jsonObject = JsonParser.parseObject(getResourceAsInputStream("npm","PackageClient-baseTestCase.json"));
     final PackageInfo packageInfo = packageClient.getPackageInfoFromJSON(jsonObject, null, null, null);
 
     assertExpectedFields(packageInfo);
@@ -41,7 +37,7 @@ public class PackageClientTest implements ResourceLoaderTests {
   @Test
   @DisplayName("test getting package from JSON works")
   public void getPackageInfoWithIdFromJSONTest() throws java.io.IOException {
-    final JsonObject jsonObject = new Gson().fromJson(new InputStreamReader(getResourceAsInputStream("npm", "PackageClient-testCaseWithId.json")), JsonObject.class);
+    final JsonObject jsonObject = JsonParser.parseObject(getResourceAsInputStream("npm", "PackageClient-testCaseWithId.json"));
     final PackageInfo packageInfo = packageClient.getPackageInfoFromJSON(jsonObject, null, null, null);
 
     assertExpectedFields(packageInfo);

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/tests/CachingPackageClientTests.java

@@ -1,14 +1,14 @@
 package org.hl7.fhir.utilities.tests;
 
+import java.io.IOException;
+import java.util.List;
+
 import org.hl7.fhir.utilities.npm.CachingPackageClient;
 import org.hl7.fhir.utilities.npm.CommonPackages;
 import org.hl7.fhir.utilities.npm.PackageInfo;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-import java.util.List;
-
 public class CachingPackageClientTests {
 
   private static final String SERVER1 = "http://packages.fhir.org";

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/tests/PackageCacheTests.java

@@ -1,5 +1,9 @@
 package org.hl7.fhir.utilities.tests;
 
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
 import org.hl7.fhir.utilities.Utilities;
 import org.hl7.fhir.utilities.npm.CommonPackages;
 import org.hl7.fhir.utilities.npm.FilesystemPackageCacheManager;
@@ -8,10 +12,6 @@ import org.hl7.fhir.utilities.npm.ToolsVersion;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
-import java.io.File;
-import java.io.IOException;
-import java.util.List;
-
 public class PackageCacheTests {
 
   @Test

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/tests/XLSXmlNormaliserTests.java

@@ -1,17 +1,12 @@
 package org.hl7.fhir.utilities.tests;
 
-import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.nio.file.StandardCopyOption;
 
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.transform.TransformerException;
 
-import org.apache.commons.io.IOUtils;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.utilities.xls.XLSXmlNormaliser;
 import org.junit.jupiter.api.Assertions;

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/tests/XhtmlNodeTest.java

@@ -1,5 +1,9 @@
 package org.hl7.fhir.utilities.tests;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.exceptions.FHIRFormatError;
 import org.hl7.fhir.utilities.xhtml.XhtmlNode;
@@ -9,10 +13,6 @@ import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.ObjectOutputStream;
-
 public class XhtmlNodeTest {
 
   private static final Logger ourLog = LoggerFactory.getLogger(XhtmlNodeTest.class);

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/tests/execution/ModuleTestExecutorTests.java

@@ -1,13 +1,13 @@
 package org.hl7.fhir.utilities.tests.execution;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
+
 import org.hl7.fhir.utilities.tests.execution.junit4.JUnit4TestExecutor;
 import org.hl7.fhir.utilities.tests.execution.junit5.JUnit5ModuleTestExecutor;
 import org.junit.jupiter.api.Test;
 
-import java.util.Arrays;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 public class ModuleTestExecutorTests {
 
   @Test