Registering default type hierarchy adapters first and allow users to override them.

This allows the default EnumTypeAdapter to be overridden for a specific hierachy adapter for Enum with anonymized sub-classes.

gson/src/main/java/com/google/gson/DefaultTypeAdapters.java

@@ -99,8 +99,12 @@ final class DefaultTypeAdapters {
   // constants will appear as nulls.
   private static final ParameterizedTypeHandlerMap<JsonSerializer<?>> DEFAULT_SERIALIZERS =
       createDefaultSerializers();
+  static final ParameterizedTypeHandlerMap<JsonSerializer<?>> DEFAULT_HIERARCHY_SERIALIZERS =
+    createDefaultHierarchySerializers();
   private static final ParameterizedTypeHandlerMap<JsonDeserializer<?>> DEFAULT_DESERIALIZERS =
       createDefaultDeserializers();
+  static final ParameterizedTypeHandlerMap<JsonDeserializer<?>> DEFAULT_HIERARCHY_DESERIALIZERS =
+    createDefaultHierarchyDeserializers();
   private static final ParameterizedTypeHandlerMap<InstanceCreator<?>> DEFAULT_INSTANCE_CREATORS =
       createDefaultInstanceCreators();
 
@@ -108,14 +112,10 @@ final class DefaultTypeAdapters {
     ParameterizedTypeHandlerMap<JsonSerializer<?>> map =
         new ParameterizedTypeHandlerMap<JsonSerializer<?>>();
 
-    map.registerForTypeHierarchy(Enum.class, ENUM_TYPE_ADAPTER);
-    map.registerForTypeHierarchy(InetAddress.class, INET_ADDRESS_ADAPTER);
     map.register(URL.class, URL_TYPE_ADAPTER);
     map.register(URI.class, URI_TYPE_ADAPTER);
     map.register(UUID.class, UUUID_TYPE_ADAPTER);
     map.register(Locale.class, LOCALE_TYPE_ADAPTER);
-    map.registerForTypeHierarchy(Collection.class, COLLECTION_TYPE_ADAPTER);
-    map.registerForTypeHierarchy(Map.class, MAP_TYPE_ADAPTER);
     map.register(Date.class, DATE_TYPE_ADAPTER);
     map.register(java.sql.Date.class, JAVA_SQL_DATE_TYPE_ADAPTER);
     map.register(Timestamp.class, DATE_TYPE_ADAPTER);
@@ -143,17 +143,24 @@ final class DefaultTypeAdapters {
     return map;
   }
 
+  private static ParameterizedTypeHandlerMap<JsonSerializer<?>> createDefaultHierarchySerializers() {
+    ParameterizedTypeHandlerMap<JsonSerializer<?>> map =
+        new ParameterizedTypeHandlerMap<JsonSerializer<?>>();
+    map.registerForTypeHierarchy(Enum.class, ENUM_TYPE_ADAPTER);
+    map.registerForTypeHierarchy(InetAddress.class, INET_ADDRESS_ADAPTER);
+    map.registerForTypeHierarchy(Collection.class, COLLECTION_TYPE_ADAPTER);
+    map.registerForTypeHierarchy(Map.class, MAP_TYPE_ADAPTER);
+    map.makeUnmodifiable();
+    return map;
+  }
+
   private static ParameterizedTypeHandlerMap<JsonDeserializer<?>> createDefaultDeserializers() {
     ParameterizedTypeHandlerMap<JsonDeserializer<?>> map =
         new ParameterizedTypeHandlerMap<JsonDeserializer<?>>();
-    map.registerForTypeHierarchy(Enum.class, wrapDeserializer(ENUM_TYPE_ADAPTER));
-    map.registerForTypeHierarchy(InetAddress.class, wrapDeserializer(INET_ADDRESS_ADAPTER));
     map.register(URL.class, wrapDeserializer(URL_TYPE_ADAPTER));
     map.register(URI.class, wrapDeserializer(URI_TYPE_ADAPTER));
     map.register(UUID.class, wrapDeserializer(UUUID_TYPE_ADAPTER));
     map.register(Locale.class, wrapDeserializer(LOCALE_TYPE_ADAPTER));
-    map.registerForTypeHierarchy(Collection.class, wrapDeserializer(COLLECTION_TYPE_ADAPTER));
-    map.registerForTypeHierarchy(Map.class, wrapDeserializer(MAP_TYPE_ADAPTER));
     map.register(Date.class, wrapDeserializer(DATE_TYPE_ADAPTER));
     map.register(java.sql.Date.class, wrapDeserializer(JAVA_SQL_DATE_TYPE_ADAPTER));
     map.register(Timestamp.class, wrapDeserializer(TIMESTAMP_DESERIALIZER));
@@ -187,6 +194,17 @@ final class DefaultTypeAdapters {
     return map;
   }
 
+  private static ParameterizedTypeHandlerMap<JsonDeserializer<?>> createDefaultHierarchyDeserializers() {
+    ParameterizedTypeHandlerMap<JsonDeserializer<?>> map =
+        new ParameterizedTypeHandlerMap<JsonDeserializer<?>>();
+    map.registerForTypeHierarchy(Enum.class, wrapDeserializer(ENUM_TYPE_ADAPTER));
+    map.registerForTypeHierarchy(InetAddress.class, wrapDeserializer(INET_ADDRESS_ADAPTER));
+    map.registerForTypeHierarchy(Collection.class, wrapDeserializer(COLLECTION_TYPE_ADAPTER));
+    map.registerForTypeHierarchy(Map.class, wrapDeserializer(MAP_TYPE_ADAPTER));
+    map.makeUnmodifiable();
+    return map;
+  }
+
   private static ParameterizedTypeHandlerMap<InstanceCreator<?>> createDefaultInstanceCreators() {
     ParameterizedTypeHandlerMap<InstanceCreator<?>> map =
         new ParameterizedTypeHandlerMap<InstanceCreator<?>>();
@@ -211,6 +229,20 @@ final class DefaultTypeAdapters {
     return getDefaultSerializers(false, LongSerializationPolicy.DEFAULT);
   }
 
+  static ParameterizedTypeHandlerMap<JsonSerializer<?>> getAllDefaultSerializers() {
+    ParameterizedTypeHandlerMap<JsonSerializer<?>> defaultSerializers =
+      getDefaultSerializers(false, LongSerializationPolicy.DEFAULT);
+    defaultSerializers.register(DEFAULT_HIERARCHY_SERIALIZERS);
+    return defaultSerializers;
+  }
+
+  static ParameterizedTypeHandlerMap<JsonDeserializer<?>> getAllDefaultDeserializers() {
+    ParameterizedTypeHandlerMap<JsonDeserializer<?>> defaultDeserializers =
+      getDefaultDeserializers().copyOf();
+    defaultDeserializers.register(DEFAULT_HIERARCHY_DESERIALIZERS);
+    return defaultDeserializers;
+  }
+
   static ParameterizedTypeHandlerMap<JsonSerializer<?>> getDefaultSerializers(
       boolean serializeSpecialFloatingPointValues, LongSerializationPolicy longSerializationPolicy) {
     ParameterizedTypeHandlerMap<JsonSerializer<?>> serializers =

gson/src/main/java/com/google/gson/Gson.java

@@ -152,8 +152,8 @@ public final class Gson {
   public Gson() {
     this(DEFAULT_EXCLUSION_STRATEGY, DEFAULT_EXCLUSION_STRATEGY, DEFAULT_NAMING_POLICY,
     new MappedObjectConstructor(DefaultTypeAdapters.getDefaultInstanceCreators()),
-    false, DefaultTypeAdapters.getDefaultSerializers(),
+    false, DefaultTypeAdapters.getAllDefaultSerializers(),
-    DefaultTypeAdapters.getDefaultDeserializers(), DEFAULT_JSON_NON_EXECUTABLE, true, false);
+    DefaultTypeAdapters.getAllDefaultDeserializers(), DEFAULT_JSON_NON_EXECUTABLE, true, false);
   }
 
   Gson(ExclusionStrategy serializationStrategy, ExclusionStrategy deserializationStrategy,

gson/src/main/java/com/google/gson/GsonBuilder.java

@@ -522,8 +522,12 @@ public final class GsonBuilder {
     ExclusionStrategy deserializationExclusionStrategy =
       new DisjunctionExclusionStrategy(deserializationStrategies);
 
-    ParameterizedTypeHandlerMap<JsonSerializer<?>> customSerializers = serializers.copyOf();
+    ParameterizedTypeHandlerMap<JsonSerializer<?>> customSerializers =
-    ParameterizedTypeHandlerMap<JsonDeserializer<?>> customDeserializers = deserializers.copyOf();
+      DefaultTypeAdapters.DEFAULT_HIERARCHY_SERIALIZERS.copyOf();
+    customSerializers.register(serializers.copyOf());
+    ParameterizedTypeHandlerMap<JsonDeserializer<?>> customDeserializers =
+      DefaultTypeAdapters.DEFAULT_HIERARCHY_DESERIALIZERS.copyOf();
+    customDeserializers.register(deserializers.copyOf());
     addTypeAdaptersForDate(datePattern, dateStyle, timeStyle, customSerializers,
         customDeserializers);
 

gson/src/main/java/com/google/gson/ParameterizedTypeHandlerMap.java

@@ -105,6 +105,21 @@ final class ParameterizedTypeHandlerMap<T> {
     }
   }
 
+  public synchronized void register(ParameterizedTypeHandlerMap<T> other) {
+    if (!modifiable) {
+      throw new IllegalStateException("Attempted to modify an unmodifiable map.");
+    }
+    for (Map.Entry<Type, T> entry : other.map.entrySet()) {
+      register(entry.getKey(), entry.getValue());
+    }
+    // Quite important to traverse the typeHierarchyList from stack bottom first since
+    // we want to register the handlers in the same order to preserve priority order
+    for (int i = other.typeHierarchyList.size()-1; i >= 0; --i) {
+      Pair<Class<?>, T> entry = other.typeHierarchyList.get(i);
+      registerForTypeHierarchy(entry);
+    }
+  }
+
   public synchronized void registerIfAbsent(Type typeOfT, T value) {
     if (!modifiable) {
       throw new IllegalStateException("Attempted to modify an unmodifiable map.");

gson/src/test/java/com/google/gson/functional/EnumTest.java

@@ -16,6 +16,14 @@
 
 package com.google.gson.functional;
 
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.EnumSet;
+import java.util.Set;
+
+import junit.framework.TestCase;
+
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonDeserializationContext;
@@ -28,14 +36,6 @@ import com.google.gson.JsonSerializer;
 import com.google.gson.common.MoreAsserts;
 import com.google.gson.reflect.TypeToken;
 
-import junit.framework.TestCase;
-
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.EnumSet;
-import java.util.Set;
-
 /**
  * Functional tests for Java 5.0 enums.
  *
@@ -120,17 +120,6 @@ public class EnumTest extends TestCase {
    * Test for issue 226.
    */
   public void testEnumSubclass() {
-    assertRoshambo();
-  }
-
-  public void disabled_testEnumSubclassWithRegisteredTypeAdapter() {
-    gson = new GsonBuilder()
-//        .registerTypeHierarchyAdapter(Roshambo.class, new MyEnumTypeAdapter())
-        .create();
-    assertRoshambo();
-  }
-
-  private void assertRoshambo() {
     assertFalse(Roshambo.class == Roshambo.ROCK.getClass());
     assertEquals("\"ROCK\"", gson.toJson(Roshambo.ROCK));
     assertEquals("[\"ROCK\",\"PAPER\",\"SCISSORS\"]", gson.toJson(EnumSet.allOf(Roshambo.class)));
@@ -139,6 +128,18 @@ public class EnumTest extends TestCase {
         gson.fromJson("[\"ROCK\",\"PAPER\",\"SCISSORS\"]", new TypeToken<Set<Roshambo>>() {}.getType()));
   }
 
+  public void testEnumSubclassWithRegisteredTypeAdapter() {
+    gson = new GsonBuilder()
+        .registerTypeHierarchyAdapter(Roshambo.class, new MyEnumTypeAdapter())
+        .create();
+    assertFalse(Roshambo.class == Roshambo.ROCK.getClass());
+    assertEquals("\"123ROCK\"", gson.toJson(Roshambo.ROCK));
+    assertEquals("[\"123ROCK\",\"123PAPER\",\"123SCISSORS\"]", gson.toJson(EnumSet.allOf(Roshambo.class)));
+    assertEquals(Roshambo.ROCK, gson.fromJson("\"123ROCK\"", Roshambo.class));
+    assertEquals(EnumSet.allOf(Roshambo.class),
+        gson.fromJson("[\"123ROCK\",\"123PAPER\",\"123SCISSORS\"]", new TypeToken<Set<Roshambo>>() {}.getType()));
+  }
+
   public enum Roshambo {
     ROCK {
       @Override Roshambo defeats() {