Support @SerializedName on annotations.

Fixes issue 347.

gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java

@@ -25,6 +25,7 @@ import com.google.gson.JsonObject;
 import com.google.gson.JsonPrimitive;
 import com.google.gson.JsonSyntaxException;
 import com.google.gson.TypeAdapter;
+import com.google.gson.annotations.SerializedName;
 import com.google.gson.internal.LazilyParsedNumber;
 import com.google.gson.reflect.TypeToken;
 import com.google.gson.stream.JsonReader;
@@ -40,6 +41,7 @@ import java.util.BitSet;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.GregorianCalendar;
+import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 import java.util.StringTokenizer;
@@ -644,21 +646,34 @@ public final class TypeAdapters {
       = newFactory(JsonElement.class, JSON_ELEMENT);
 
   private static final class EnumTypeAdapter<T extends Enum<T>> extends TypeAdapter<T> {
-    private final Class<T> classOfT;
+    private final Map<String, T> nameToConstant = new HashMap<String, T>();
+    private final Map<T, String> constantToName = new HashMap<T, String>();
 
     public EnumTypeAdapter(Class<T> classOfT) {
-      this.classOfT = classOfT;
+      try {
+        for (T constant : classOfT.getEnumConstants()) {
+          String name = constant.name();
+          SerializedName annotation = classOfT.getField(name).getAnnotation(SerializedName.class);
+          if (annotation != null) {
+            name = annotation.value();
+          }
+          nameToConstant.put(name, constant);
+          constantToName.put(constant, name);
+        }
+      } catch (NoSuchFieldException e) {
+        throw new AssertionError();
+      }
     }
     public T read(JsonReader in) throws IOException {
       if (in.peek() == JsonToken.NULL) {
         in.nextNull();
         return null;
       }
-      return Enum.valueOf(classOfT, in.nextString());
+      return nameToConstant.get(in.nextString());
     }
 
     public void write(JsonWriter out, T value) throws IOException {
-      out.value(value == null ? null : value.name());
+      out.value(value == null ? null : constantToName.get(value));
     }
   }
 

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

@@ -25,16 +25,15 @@ import com.google.gson.JsonParseException;
 import com.google.gson.JsonPrimitive;
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
+import com.google.gson.annotations.SerializedName;
 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;
+import junit.framework.TestCase;
 
 /**
  * Functional tests for Java 5.0 enums.
@@ -144,6 +143,11 @@ public class EnumTest extends TestCase {
     MoreAsserts.assertContains(actualJsonList, Roshambo.PAPER);
   }
 
+  public void testEnumCaseMapping() {
+    assertEquals(Gender.MALE, gson.fromJson("\"boy\"", Gender.class));
+    assertEquals("\"boy\"", gson.toJson(Gender.MALE, Gender.class));
+  }
+
   public enum Roshambo {
     ROCK {
       @Override Roshambo defeats() {
@@ -175,4 +179,12 @@ public class EnumTest extends TestCase {
       return Roshambo.valueOf(json.getAsString().substring(3));
     }
   }
+
+  public enum Gender {
+    @SerializedName("boy")
+    MALE,
+
+    @SerializedName("girl")
+    FEMALE
+  }
 }