fix json issue, and add tests for it

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

@@ -354,6 +354,7 @@ public class TerminologyCache {
   private void load() throws FHIRException {
     for (String fn : new File(folder).list()) {
       if (fn.endsWith(".cache") && !fn.equals("validation.cache")) {
+        int c = 0;
         try {
           String title = fn.substring(0, fn.lastIndexOf("."));
           NamedCache nc = new NamedCache();
@@ -364,6 +365,7 @@ public class TerminologyCache {
             src = src.substring(1);
           int i = src.indexOf(ENTRY_MARKER); 
           while (i > -1) {
+            c++;
             String s = src.substring(0, i);
             src = src.substring(i+ENTRY_MARKER.length()+1);
             i = src.indexOf(ENTRY_MARKER);
@@ -395,7 +397,7 @@ public class TerminologyCache {
             }
           }        
         } catch (Exception e) {
-          throw new FHIRException("Error loading "+fn+": "+e.getMessage(), e);
+          throw new FHIRException("Error loading "+fn+": "+e.getMessage()+" entry "+c, e);
         }
       }
     }

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/formats/JsonCreatorDirect.java

@@ -34,6 +34,8 @@ package org.hl7.fhir.r5.formats;
 import java.io.IOException;
 import java.io.Writer;
 import java.math.BigDecimal;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.hl7.fhir.utilities.Utilities;
 
@@ -48,7 +50,7 @@ public class JsonCreatorDirect implements JsonCreator {
   private Writer writer;
   private boolean pretty;
   private boolean named;
-  private boolean valued;
+  private List<Boolean> valued = new ArrayList<Boolean>();
   private int indent;
   
   public JsonCreatorDirect(Writer writer) {
@@ -66,6 +68,10 @@ public class JsonCreatorDirect implements JsonCreator {
     checkState();
     writer.write("{");
     stepIn();
+    if (!valued.isEmpty()) {
+      valued.set(0, true);      
+    }
+    valued.add(0, false);
   }
 
   public void stepIn() throws IOException {
@@ -96,7 +102,7 @@ public class JsonCreatorDirect implements JsonCreator {
         writer.write(":");
       named = false;
     }
-    if (valued) {
+    if (!valued.isEmpty() && valued.get(0)) {
       writer.write(",");
       if (pretty) {
         writer.write("\r\n");
@@ -104,7 +110,7 @@ public class JsonCreatorDirect implements JsonCreator {
           writer.write("  ");
         }        
       }
-      valued = false;
+      valued.set(0, false);
     }
   }
 
@@ -112,13 +118,14 @@ public class JsonCreatorDirect implements JsonCreator {
   public void endObject() throws IOException {
     stepOut();
     writer.write("}");    
+    valued.remove(0);
   }
 
   @Override
   public void nullValue() throws IOException {
     checkState();
     writer.write("null");
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
@@ -132,7 +139,7 @@ public class JsonCreatorDirect implements JsonCreator {
   public void value(String value) throws IOException {
     checkState();
     writer.write("\""+Utilities.escapeJson(value)+"\"");    
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
@@ -144,7 +151,7 @@ public class JsonCreatorDirect implements JsonCreator {
       writer.write("true");
     else
       writer.write("false");
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
@@ -154,7 +161,7 @@ public class JsonCreatorDirect implements JsonCreator {
       writer.write("null");
     else 
       writer.write(value.toString());    
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
@@ -164,7 +171,7 @@ public class JsonCreatorDirect implements JsonCreator {
       writer.write("null");
     else 
       writer.write(value);    
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
@@ -174,23 +181,28 @@ public class JsonCreatorDirect implements JsonCreator {
       writer.write("null");
     else 
       writer.write(value.toString());    
-    valued = true;
+    valued.set(0, true);
   }
 
   @Override
   public void beginArray() throws IOException {
     checkState();
     writer.write("[");    
+    if (!valued.isEmpty()) {
+      valued.set(0, true);      
+    }
+    valued.add(0, false);
   }
 
   @Override
   public void endArray() throws IOException {
     writer.write("]");        
+    valued.remove(0);
   }
 
   @Override
   public void finish() throws IOException {
-    // nothing
+    writer.flush();
   }
 
   @Override

org.hl7.fhir.r5/src/test/java/org/hl7/fhir/r5/test/JsonDirectTests.java

@@ -1,14 +1,17 @@
 package org.hl7.fhir.r5.test;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
 
 import org.apache.commons.io.FileUtils;
 import org.hl7.fhir.exceptions.FHIRFormatError;
 import org.hl7.fhir.r5.formats.IParser.OutputStyle;
+import org.hl7.fhir.r5.formats.JsonCreatorDirect;
 import org.hl7.fhir.r5.formats.JsonParser;
 import org.hl7.fhir.r5.formats.XmlParser;
 import org.hl7.fhir.r5.model.Observation;
@@ -16,6 +19,8 @@ import org.hl7.fhir.utilities.Utilities;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
+import junit.framework.Assert;
+
 public class JsonDirectTests {
 
   @Test
@@ -33,4 +38,30 @@ public class JsonDirectTests {
     new XmlParser().setOutputStyle(OutputStyle.PRETTY).compose(new FileOutputStream(xml), obs);
   }
 
+  @Test
+  public void testEmptyObject() throws FHIRFormatError, FileNotFoundException, IOException {
+    ByteArrayOutputStream bs = new ByteArrayOutputStream();
+    JsonCreatorDirect json = new JsonCreatorDirect(new OutputStreamWriter(bs, "UTF-8"));
+    json.beginObject();
+    json.name("a");
+    json.beginObject();
+    json.endObject();
+    json.name("b");
+    json.beginArray();
+    json.beginObject();
+    json.endObject();
+    json.beginObject();
+    json.endObject();
+    json.endArray();
+    json.name("c");
+    json.beginArray();
+    json.endArray();
+    json.name("test");
+    json.value("test");
+    json.endObject();
+    json.finish();
+    String s = new String(bs.toByteArray());
+    Assert.assertEquals("{\"a\":{},\"b\":[{},{}],\"c\":[],\"test\":\"test\"}", s);
+  }
+
 }