HDFS-11712. Ozone: Reuse ObjectMapper instance to improve the performance. Contributed by Yiqun Lin.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/exceptions/OzoneException.java

@@ -19,19 +19,35 @@
 package org.apache.hadoop.ozone.web.exceptions;
 
 
-import org.apache.hadoop.classification.InterfaceAudience;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonProperty;
-import org.codehaus.jackson.map.ObjectMapper;
-
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+
 /**
  * Class the represents various errors returned by the
  * Ozone Layer.
  */
 @InterfaceAudience.Private
 public class OzoneException extends Exception {
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(OzoneException.class);
+  private static final ObjectMapper MAPPER;
+
+  static {
+    MAPPER = new ObjectMapper();
+    MAPPER.setVisibility(
+        MAPPER.getSerializationConfig().getDefaultVisibilityChecker()
+            .withCreatorVisibility(JsonAutoDetect.Visibility.NONE)
+            .withFieldVisibility(JsonAutoDetect.Visibility.NONE)
+            .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
+            .withIsGetterVisibility(JsonAutoDetect.Visibility.NONE)
+            .withSetterVisibility(JsonAutoDetect.Visibility.NONE));
+  }
 
   @JsonProperty("httpCode")
   private long httpCode;
@@ -211,15 +227,7 @@ public class OzoneException extends Exception {
    */
   public String toJsonString() {
     try {
-      ObjectMapper mapper = new ObjectMapper();
-      mapper.setVisibilityChecker(
-          mapper.getSerializationConfig().getDefaultVisibilityChecker()
-              .withCreatorVisibility(JsonAutoDetect.Visibility.NONE)
-              .withFieldVisibility(JsonAutoDetect.Visibility.NONE)
-              .withGetterVisibility(JsonAutoDetect.Visibility.NONE)
-              .withIsGetterVisibility(JsonAutoDetect.Visibility.NONE)
-              .withSetterVisibility(JsonAutoDetect.Visibility.NONE));
-      return mapper.writeValueAsString(this);
+      return MAPPER.writeValueAsString(this);
     } catch (IOException ex) {
       // TODO : Log this error on server side.
     }
@@ -237,7 +245,6 @@ public class OzoneException extends Exception {
    * @throws IOException
    */
   public static OzoneException parse(String jsonString) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(jsonString, OzoneException.class);
+    return READER.readValue(jsonString);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/bucket/CreateBucketHandler.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -89,11 +89,8 @@ public class CreateBucketHandler extends Handler {
     OzoneBucket bucket = vol.createBucket(bucketName);
 
     if (cmd.hasOption(Shell.VERBOSE)) {
-      ObjectMapper mapper = new ObjectMapper();
-      Object json = mapper.readValue(bucket.getBucketInfo().toJsonString(),
-          Object.class);
-      System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-          .writeValueAsString(json));
+      System.out.printf("%s%n", JsonUtils.toJsonStringWithDefaultPrettyPrinter(
+          bucket.getBucketInfo().toJsonString()));
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/bucket/InfoBucketHandler.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -87,11 +87,8 @@ public class InfoBucketHandler extends Handler {
     OzoneVolume vol = client.getVolume(volumeName);
     OzoneBucket bucket = vol.getBucket(bucketName);
 
-    ObjectMapper mapper = new ObjectMapper();
-    Object json =
-        mapper.readValue(bucket.getBucketInfo().toJsonString(), Object.class);
-    System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-        .writeValueAsString(json));
+    System.out.printf("%s%n", JsonUtils.toJsonStringWithDefaultPrettyPrinter(
+        bucket.getBucketInfo().toJsonString()));
   }
 
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/bucket/ListBucketHandler.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -85,14 +85,9 @@ public class ListBucketHandler extends Handler {
     OzoneVolume vol = client.getVolume(volumeName);
     List<OzoneBucket> bucketList = vol.listBuckets();
 
-    ObjectMapper mapper = new ObjectMapper();
-
-
     for (OzoneBucket bucket : bucketList) {
-      Object json =
-          mapper.readValue(bucket.getBucketInfo().toJsonString(), Object.class);
-      System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-          .writeValueAsString(json));
+      System.out.printf("%s%n", JsonUtils.toJsonStringWithDefaultPrettyPrinter(
+          bucket.getBucketInfo().toJsonString()));
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/bucket/UpdateBucketHandler.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -88,11 +88,7 @@ public class UpdateBucketHandler extends Handler {
     }
 
     OzoneBucket bucket = vol.getBucket(bucketName);
-
-    ObjectMapper mapper = new ObjectMapper();
-    Object json =
-        mapper.readValue(bucket.getBucketInfo().toJsonString(), Object.class);
-    System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-        .writeValueAsString(json));
+    System.out.printf("%s%n", JsonUtils.toJsonStringWithDefaultPrettyPrinter(
+        bucket.getBucketInfo().toJsonString()));
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/keys/ListKeyHandler.java

@@ -26,7 +26,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -90,16 +90,10 @@ public class ListKeyHandler extends Handler {
     OzoneBucket bucket = vol.getBucket(bucketName);
     List<OzoneKey> keys = bucket.listKeys();
 
-    ObjectMapper mapper = new ObjectMapper();
-
-
     for (OzoneKey key : keys) {
-      Object json =
-          mapper.readValue(key.getObjectInfo().toJsonString(), Object.class);
-      System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-          .writeValueAsString(json));
+      System.out.printf("%s%n", JsonUtils.toJsonStringWithDefaultPrettyPrinter(
+          key.getObjectInfo().toJsonString()));
     }
-
   }
 
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/volume/CreateVolumeHandler.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -89,13 +89,10 @@ public class CreateVolumeHandler extends Handler {
     client.setEndPointURI(ozoneURI);
     client.setUserAuth(rootName);
 
-
     OzoneVolume vol = client.createVolume(volumeName, userName, quota);
     if (cmd.hasOption(Shell.VERBOSE)) {
-      ObjectMapper mapper = new ObjectMapper();
-      Object json = mapper.readValue(vol.getJsonString(), Object.class);
-      System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-          .writeValueAsString(json));
+      System.out.printf("%s%n",
+          JsonUtils.toJsonStringWithDefaultPrettyPrinter(vol.getJsonString()));
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/volume/InfoVolumeHandler.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -89,11 +89,7 @@ public class InfoVolumeHandler extends Handler{
     client.setUserAuth(rootName);
 
     OzoneVolume vol = client.getVolume(volumeName);
-    ObjectMapper mapper = new ObjectMapper();
-    Object json = mapper.readValue(vol.getJsonString(), Object.class);
-    System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-                          .writeValueAsString(json));
-
-
+    System.out.printf("%s%n",
+        JsonUtils.toJsonStringWithDefaultPrettyPrinter(vol.getJsonString()));
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/ozShell/volume/ListVolumeHandler.java

@@ -24,7 +24,7 @@ import org.apache.hadoop.ozone.web.client.OzoneVolume;
 import org.apache.hadoop.ozone.web.exceptions.OzoneException;
 import org.apache.hadoop.ozone.web.ozShell.Handler;
 import org.apache.hadoop.ozone.web.ozShell.Shell;
-import org.codehaus.jackson.map.ObjectMapper;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
 import java.io.IOException;
 import java.net.URI;
@@ -86,14 +86,11 @@ public class ListVolumeHandler extends Handler {
         System.out.printf("Found : %d volumes for user : %s %n", volumes.size(),
             userName);
       }
-      ObjectMapper mapper = new ObjectMapper();
 
       for (OzoneVolume vol : volumes) {
-        Object json = mapper.readValue(vol.getJsonString(), Object.class);
-        System.out.printf("%s%n", mapper.writerWithDefaultPrettyPrinter()
-            .writeValueAsString(json));
+        System.out.printf("%s%n", JsonUtils
+            .toJsonStringWithDefaultPrettyPrinter(vol.getJsonString()));
       }
-
     }
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/BucketInfo.java

@@ -17,29 +17,48 @@
  */
 package org.apache.hadoop.ozone.web.response;
 
-import com.google.common.base.Preconditions;
-import org.apache.hadoop.fs.StorageType;
-import org.apache.hadoop.ozone.web.request.OzoneAcl;
-import org.apache.hadoop.ozone.OzoneConsts;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
-
 import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.apache.hadoop.fs.StorageType;
+import org.apache.hadoop.ozone.OzoneConsts;
+import org.apache.hadoop.ozone.web.request.OzoneAcl;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+import com.google.common.base.Preconditions;
+
 /**
  * BucketInfo class, this is used as response class to send
  * Json info about a bucket back to a client.
  */
 public class BucketInfo implements Comparable<BucketInfo> {
   static final String BUCKET_INFO = "BUCKET_INFO_FILTER";
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(BucketInfo.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"bytesUsed", "keyCount"};
+
+    FilterProvider filters = new SimpleFilterProvider().addFilter(BUCKET_INFO,
+        SimpleBeanPropertyFilter.serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
+
   private String volumeName;
   private String bucketName;
   private List<OzoneAcl> acls;
@@ -77,8 +96,7 @@ public class BucketInfo implements Comparable<BucketInfo> {
    * @throws IOException
    */
   public static BucketInfo parse(String jsonString) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(jsonString, BucketInfo.class);
+    return READER.readValue(jsonString);
   }
 
   /**
@@ -161,18 +179,7 @@ public class BucketInfo implements Comparable<BucketInfo> {
    * @return String
    */
   public String toJsonString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    String[] ignorableFieldNames = {"bytesUsed", "keyCount"};
-
-    FilterProvider filters = new SimpleFilterProvider().addFilter(
-        BUCKET_INFO,
-        SimpleBeanPropertyFilter.serializeAllExcept(ignorableFieldNames));
-
-    mapper.setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
@@ -185,8 +192,7 @@ public class BucketInfo implements Comparable<BucketInfo> {
    * fields vs. only fields that are part of REST protocol.
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/KeyInfo.java

@@ -17,24 +17,46 @@
  */
 package org.apache.hadoop.ozone.web.response;
 
+import java.io.IOException;
+
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.apache.commons.lang.builder.HashCodeBuilder;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
-import java.io.IOException;
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
 
 /**
  * Represents an Ozone key Object.
  */
 public class KeyInfo implements Comparable<KeyInfo> {
   static final String OBJECT_INFO = "OBJECT_INFO_FILTER";
+
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(KeyInfo.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"dataFileName"};
+
+    FilterProvider filters = new SimpleFilterProvider()
+        .addFilter(OBJECT_INFO, SimpleBeanPropertyFilter
+            .serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD,
+        JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
+
   /**
    * This class allows us to create custom filters
    * for the Json serialization.
@@ -225,8 +247,7 @@ public class KeyInfo implements Comparable<KeyInfo> {
    * @throws IOException
    */
   public static KeyInfo parse(String jsonString) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(jsonString, KeyInfo.class);
+    return READER.readValue(jsonString);
   }
 
 
@@ -237,25 +258,13 @@ public class KeyInfo implements Comparable<KeyInfo> {
    * @return String
    */
   public String toJsonString() throws IOException {
-    String[] ignorableFieldNames = {"dataFileName"};
-
-    FilterProvider filters = new SimpleFilterProvider()
-        .addFilter(OBJECT_INFO, SimpleBeanPropertyFilter
-            .serializeAllExcept(ignorableFieldNames));
-
-    ObjectMapper mapper = new ObjectMapper()
-        .setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
    * Returns the Object as a Json String.
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/ListBuckets.java

@@ -18,25 +18,46 @@
 package org.apache.hadoop.ozone.web.response;
 
 
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
-
 import java.io.IOException;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+
 /**
  * List Bucket is the response for the ListBucket Query.
  */
 public class ListBuckets {
   static final String BUCKET_LIST = "BUCKET_LIST_FILTER";
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(ListBuckets.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"dataFileName"};
+
+    FilterProvider filters = new SimpleFilterProvider()
+        .addFilter(BUCKET_LIST, SimpleBeanPropertyFilter
+            .serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD,
+        JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
+
   private List<BucketInfo> buckets;
 
   /**
@@ -65,8 +86,7 @@ public class ListBuckets {
    * @throws IOException
    */
   public static ListBuckets parse(String data) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(data, ListBuckets.class);
+    return READER.readValue(data);
   }
 
   /**
@@ -95,27 +115,14 @@ public class ListBuckets {
    * @return String
    */
   public String toJsonString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    String[] ignorableFieldNames = {"bytesUsed", "keyCount"};
-
-    FilterProvider filters = new SimpleFilterProvider()
-        .addFilter(BUCKET_LIST, SimpleBeanPropertyFilter
-        .serializeAllExcept(ignorableFieldNames));
-
-    mapper.setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
    * Returns the Object as a Json String.
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/ListKeys.java

@@ -17,28 +17,50 @@
  */
 package org.apache.hadoop.ozone.web.response;
 
-import com.google.common.base.Preconditions;
-import org.apache.hadoop.ozone.web.handlers.BucketArgs;
-import org.apache.hadoop.ozone.web.handlers.ListArgs;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
-
 import java.io.IOException;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.apache.hadoop.ozone.web.handlers.BucketArgs;
+import org.apache.hadoop.ozone.web.handlers.ListArgs;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+import com.google.common.base.Preconditions;
+
 /**
  * This class the represents the list of keys (Objects) in a bucket.
  */
 public class ListKeys {
   static final String OBJECT_LIST = "OBJECT_LIST_FILTER";
+
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(ListKeys.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"dataFileName"};
+
+    FilterProvider filters = new SimpleFilterProvider()
+        .addFilter(OBJECT_LIST, SimpleBeanPropertyFilter
+            .serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD,
+        JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
+
   private String name;
   private String prefix;
   private long maxKeys;
@@ -73,8 +95,7 @@ public class ListKeys {
    * @throws IOException - Json conversion error.
    */
   public static ListKeys parse(String jsonString) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(jsonString, ListKeys.class);
+    return READER.readValue(jsonString);
   }
 
   /**
@@ -148,17 +169,7 @@ public class ListKeys {
    * @throws  IOException - On json Errors.
    */
   public String toJsonString() throws IOException {
-    String[] ignorableFieldNames = {"dataFileName"};
-
-    FilterProvider filters = new SimpleFilterProvider().addFilter(OBJECT_LIST,
-        SimpleBeanPropertyFilter.serializeAllExcept(ignorableFieldNames));
-
-    ObjectMapper mapper = new ObjectMapper()
-        .setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
@@ -168,8 +179,7 @@ public class ListKeys {
    * @throws IOException - on json errors.
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/ListVolumes.java

@@ -17,21 +17,24 @@
  */
 package org.apache.hadoop.ozone.web.response;
 
-import org.apache.hadoop.classification.InterfaceAudience;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
-
 import java.io.IOException;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+
 /**
  * List Volume Class is the class that is returned in JSON format to
  * users when they call ListVolumes.
@@ -41,6 +44,23 @@ public class ListVolumes {
   private List<VolumeInfo> volumes;
 
   static final String VOLUME_LIST = "VOLUME_LIST_FILTER";
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(ListVolumes.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"bytesUsed", "bucketCount"};
+
+    FilterProvider filters = new SimpleFilterProvider()
+        .addFilter(VOLUME_LIST, SimpleBeanPropertyFilter
+            .serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD,
+        JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
 
   /**
    * Used for json filtering.
@@ -82,19 +102,7 @@ public class ListVolumes {
    * @return String
    */
   public String toJsonString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    String[] ignorableFieldNames = {"bytesUsed", "bucketCount"};
-
-    FilterProvider filters = new SimpleFilterProvider()
-        .addFilter(VOLUME_LIST,
-            SimpleBeanPropertyFilter.serializeAllExcept(ignorableFieldNames));
-
-    mapper.setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
@@ -108,8 +116,7 @@ public class ListVolumes {
    * @throws IOException
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 
   /**
@@ -122,8 +129,7 @@ public class ListVolumes {
    * @throws IOException
    */
   public static ListVolumes parse(String data) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(data, ListVolumes.class);
+    return READER.readValue(data);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/response/VolumeInfo.java

@@ -19,18 +19,21 @@
 package org.apache.hadoop.ozone.web.response;
 
 
+import java.io.IOException;
+
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.ozone.web.request.OzoneQuota;
-import org.codehaus.jackson.annotate.JsonAutoDetect;
-import org.codehaus.jackson.annotate.JsonMethod;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.map.ObjectWriter;
-import org.codehaus.jackson.map.annotate.JsonFilter;
-import org.codehaus.jackson.map.ser.FilterProvider;
-import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
-import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
+import org.apache.hadoop.ozone.web.utils.JsonUtils;
 
-import java.io.IOException;
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
+import com.fasterxml.jackson.annotation.JsonFilter;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
 
 /**
  * VolumeInfo Class is the Java class that represents
@@ -40,6 +43,23 @@ import java.io.IOException;
 public class VolumeInfo implements Comparable<VolumeInfo> {
 
   static final String VOLUME_INFO = "VOLUME_INFO_FILTER";
+  private static final ObjectReader READER =
+      new ObjectMapper().readerFor(VolumeInfo.class);
+  private static final ObjectWriter WRITER;
+
+  static {
+    ObjectMapper mapper = new ObjectMapper();
+    String[] ignorableFieldNames = {"bytesUsed", "bucketCount"};
+
+    FilterProvider filters = new SimpleFilterProvider()
+        .addFilter(VOLUME_INFO, SimpleBeanPropertyFilter
+            .serializeAllExcept(ignorableFieldNames));
+    mapper.setVisibility(PropertyAccessor.FIELD,
+        JsonAutoDetect.Visibility.ANY);
+    mapper.addMixIn(Object.class, MixIn.class);
+
+    WRITER = mapper.writer(filters);
+  }
 
   /**
    * Custom Json Filter Class.
@@ -174,19 +194,7 @@ public class VolumeInfo implements Comparable<VolumeInfo> {
    * @throws IOException
    */
   public String toJsonString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    String[] ignorableFieldNames = {"bytesUsed", "bucketCount"};
-
-    FilterProvider filters = new SimpleFilterProvider()
-        .addFilter(VOLUME_INFO, SimpleBeanPropertyFilter
-            .serializeAllExcept(ignorableFieldNames));
-
-    mapper.setVisibility(JsonMethod.FIELD, JsonAutoDetect.Visibility.ANY);
-    mapper.getSerializationConfig()
-        .addMixInAnnotations(Object.class, MixIn.class);
-    ObjectWriter writer = mapper.writer(filters);
-
-    return writer.writeValueAsString(this);
+    return WRITER.writeValueAsString(this);
   }
 
   /**
@@ -200,8 +208,7 @@ public class VolumeInfo implements Comparable<VolumeInfo> {
    * @throws IOException
    */
   public String toDBString() throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.writeValueAsString(this);
+    return JsonUtils.toJsonString(this);
   }
 
 
@@ -243,8 +250,7 @@ public class VolumeInfo implements Comparable<VolumeInfo> {
    * @throws IOException
    */
   public static VolumeInfo parse(String data) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(data, VolumeInfo.class);
+    return READER.readValue(data);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/utils/JsonUtils.java

@@ -0,0 +1,53 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.apache.hadoop.ozone.web.utils;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.ObjectWriter;
+
+/**
+ * JSON Utility functions used in ozone.
+ */
+public final class JsonUtils {
+
+  // Reuse ObjectMapper instance for improving performance.
+  // ObjectMapper is thread safe as long as we always configure instance
+  // before use.
+  private static final ObjectMapper MAPPER = new ObjectMapper();
+  private static final ObjectReader READER = MAPPER.readerFor(Object.class);
+  private static final ObjectWriter WRITTER =
+      MAPPER.writerWithDefaultPrettyPrinter();
+
+  private JsonUtils() {
+    // Never constructed
+  }
+
+  public static String toJsonStringWithDefaultPrettyPrinter(String jsonString)
+      throws IOException {
+    Object json = READER.readValue(jsonString);
+    return WRITTER.writeValueAsString(json);
+  }
+
+  public static String toJsonString(Object obj) throws IOException {
+    return MAPPER.writeValueAsString(obj);
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/web/utils/package-info.java

@@ -0,0 +1,18 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.ozone.web.utils;