X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=src%2Fcom%2Fgoogle%2Fgson%2FJsonSerializer.java;fp=src%2Fcom%2Fgoogle%2Fgson%2FJsonSerializer.java;h=a6050033646ac0e78aaa6af5ef1dd1bedaa487a1;hb=cfd903b6b5113fa28991db19bf98d0340ae709a4;hp=0000000000000000000000000000000000000000;hpb=819197b2305a94ab4924c5ae37a3fad762078448;p=unical.git diff --git a/src/com/google/gson/JsonSerializer.java b/src/com/google/gson/JsonSerializer.java new file mode 100644 index 0000000..a605003 --- /dev/null +++ b/src/com/google/gson/JsonSerializer.java @@ -0,0 +1,89 @@ +/* + * Copyright (C) 2008 Google Inc. + * + * Licensed 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 com.google.gson; + +import java.lang.reflect.Type; + +/** + * Interface representing a custom serializer for Json. You should write a custom serializer, if + * you are not happy with the default serialization done by Gson. You will also need to register + * this serializer through {@link com.google.gson.GsonBuilder#registerTypeAdapter(Type, Object)}. + * + *

Let us look at example where defining a serializer will be useful. The {@code Id} class + * defined below has two fields: {@code clazz} and {@code value}.

+ * + *

+ * public class Id<T> {
+ *   private final Class<T> clazz;
+ *   private final long value;
+ *
+ *   public Id(Class<T> clazz, long value) {
+ *     this.clazz = clazz;
+ *     this.value = value;
+ *   }
+ *
+ *   public long getValue() {
+ *     return value;
+ *   }
+ * }
+ * 

+ * + *

The default serialization of {@code Id(com.foo.MyObject.class, 20L)} will be + * {"clazz":com.foo.MyObject,"value":20}. Suppose, you just want the output to be + * the value instead, which is {@code 20} in this case. You can achieve that by writing a custom + * serializer:

+ * + *

+ * class IdSerializer implements JsonSerializer<Id>() {
+ *   public JsonElement serialize(Id id, Type typeOfId, JsonSerializationContext context) {
+ *     return new JsonPrimitive(id.getValue());
+ *   }
+ * }
+ * 

+ * + *

You will also need to register {@code IdSerializer} with Gson as follows:

+ *
+ * Gson gson = new GsonBuilder().registerTypeAdapter(Id.class, new IdSerializer()).create();
+ * 
+ * + *

New applications should prefer {@link TypeAdapter}, whose streaming API + * is more efficient than this interface's tree API. + * + * @author Inderjeet Singh + * @author Joel Leitch + * + * @param type for which the serializer is being registered. It is possible that a serializer + * may be asked to serialize a specific generic type of the T. + */ +public interface JsonSerializer { + + /** + * Gson invokes this call-back method during serialization when it encounters a field of the + * specified type. + * + *

In the implementation of this call-back method, you should consider invoking + * {@link JsonSerializationContext#serialize(Object, Type)} method to create JsonElements for any + * non-trivial field of the {@code src} object. However, you should never invoke it on the + * {@code src} object itself since that will cause an infinite loop (Gson will call your + * call-back method again).

+ * + * @param src the object that needs to be converted to Json. + * @param typeOfSrc the actual type (fully genericized version) of the source object. + * @return a JsonElement corresponding to the specified object. + */ + public JsonElement serialize(T src, Type typeOfSrc, JsonSerializationContext context); +}