Remove duplicate JSON keys. Closes #2068.

main/src/com/google/refine/browsing/facets/FacetConfig.java

@@ -26,7 +26,7 @@
  ******************************************************************************/
 package com.google.refine.browsing.facets;
 
-import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
@@ -63,6 +63,6 @@ public interface FacetConfig  {
     /**
      * The facet type as stored in json.
      */
-    @JsonProperty("type")
+    @JsonIgnore // already included by @JsonTypeInfo
     public String getJsonType();
 }

main/src/com/google/refine/clustering/ClustererConfig.java

@@ -26,6 +26,7 @@
  ******************************************************************************/
 package com.google.refine.clustering;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
@@ -70,6 +71,6 @@ public abstract class ClustererConfig  {
     /**
      * Type string used in Json serialization
      */
-    @JsonProperty("type")
+    @JsonIgnore // already added by @JsonTypeInfo
     public abstract String getType();
 }

main/src/com/google/refine/model/AbstractOperation.java

@@ -35,6 +35,7 @@ package com.google.refine.model;
 
 import java.util.Properties;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.databind.annotation.JsonTypeIdResolver;
@@ -72,7 +73,7 @@ abstract public class AbstractOperation  {
         throw new UnsupportedOperationException();
     }
     
-    @JsonProperty("op")
+    @JsonIgnore // the operation id is already added as "op" by the JsonTypeInfo annotation
     public String getOperationId() {
         return OperationRegistry.s_opClassToName.get(this.getClass());
     }

main/src/com/google/refine/preference/PreferenceValue.java

@@ -26,8 +26,8 @@
  ******************************************************************************/
 package com.google.refine.preference;
 
-import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
  * Interface to be extended by all objects stored 
@@ -40,7 +40,7 @@ import com.fasterxml.jackson.annotation.JsonTypeInfo;
 
 @JsonTypeInfo(
         use=JsonTypeInfo.Id.CLASS,
-        include=JsonTypeInfo.As.PROPERTY,
+        include=JsonTypeInfo.As.EXISTING_PROPERTY,
         property="class")
 public interface PreferenceValue {
 	

main/src/com/google/refine/sorting/Criterion.java

@@ -70,7 +70,7 @@ abstract public class Criterion  {
     @JsonProperty("reverse")
     public boolean reverse = false;
 
-    @JsonProperty("valueType")
+    @JsonIgnore // already added by @JsonTypeInfo
     public abstract String getValueType();
     
     // Returns a cached cell index

main/tests/server/src/com/google/refine/tests/preference/TopListTests.java

@@ -27,11 +27,13 @@
 package com.google.refine.tests.preference;
 
 import java.io.IOException;
+import java.util.Collections;
 
 import org.testng.annotations.Test;
 
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.JsonMappingException;
+import com.google.refine.preference.PreferenceValue;
 import com.google.refine.preference.TopList;
 import com.google.refine.tests.util.TestUtils;
 import com.google.refine.util.ParsingUtilities;
@@ -50,8 +52,12 @@ public class TopListTests {
                 + "   \"grel:value.parseJson()[\\\"employment-summary\\\"].join('###')\","
                 + "   \"grel:\\\"https://pub.orcid.org/\\\"+value+\\\"/employments\\\"\""
                 + "]}";
+        PreferenceValue prefValue = ParsingUtilities.mapper.readValue(json, PreferenceValue.class);
         TestUtils.isSerializedTo(
-                ParsingUtilities.mapper.readValue(json, TopList.class),
+                prefValue,
                 json);
+        
+        String mapJson = "{\"key\":"+json+"}";
+        TestUtils.isSerializedTo(Collections.singletonMap("key",prefValue), mapJson);
     }
 }

main/tests/server/src/com/google/refine/tests/util/TestUtils.java

@@ -35,8 +35,11 @@ import java.io.LineNumberReader;
 import java.io.StringReader;
 import java.io.StringWriter;
 
+import com.fasterxml.jackson.core.JsonFactory.Feature;
 import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.MapperFeature;
@@ -50,7 +53,11 @@ public class TestUtils {
     
     static ObjectMapper mapper = new ObjectMapper();
     static {
-        mapper = mapper.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);
+        mapper = mapper.enable(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS);
+        // Reject duplicate fields because the previous implementation with org.json
+        // does not accept them. It is also cleaner and more compact.
+        mapper = mapper.enable(JsonParser.Feature.STRICT_DUPLICATE_DETECTION);
+        mapper = mapper.enable(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY);
     }
 
     /**