/*
 * 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.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

An annotation that indicates the version number since a member or a type has been present. This annotation is useful to manage versioning of your Json classes for a web-service.

This annotation has no effect unless you build Gson with a GsonBuilder and invoke GsonBuilder.setVersion(double) method.

Here is an example of how this annotation is meant to be used:

public class User {
  private String firstName;
  private String lastName;
  @Since(1.0) private String emailAddress;
  @Since(1.0) private String password;
  @Since(1.1) private Address address;
}

If you created Gson with new Gson(), the toJson() and fromJson() methods will use all the fields for serialization and deserialization. However, if you created Gson with Gson gson = new GsonBuilder().setVersion(1.0).create() then the toJson() and fromJson() methods of Gson will exclude the address field since it's version number is set to 1.1.

Author:Inderjeet Singh, Joel Leitch
/** * An annotation that indicates the version number since a member or a type has been present. * This annotation is useful to manage versioning of your Json classes for a web-service. * * <p> * This annotation has no effect unless you build {@link com.google.gson.Gson} with a * {@link com.google.gson.GsonBuilder} and invoke * {@link com.google.gson.GsonBuilder#setVersion(double)} method. * * <p>Here is an example of how this annotation is meant to be used:</p> * <pre> * public class User { * private String firstName; * private String lastName; * &#64Since(1.0) private String emailAddress; * &#64Since(1.0) private String password; * &#64Since(1.1) private Address address; * } * </pre> * * <p>If you created Gson with {@code new Gson()}, the {@code toJson()} and {@code fromJson()} * methods will use all the fields for serialization and deserialization. However, if you created * Gson with {@code Gson gson = new GsonBuilder().setVersion(1.0).create()} then the * {@code toJson()} and {@code fromJson()} methods of Gson will exclude the {@code address} field * since it's version number is set to {@code 1.1}.</p> * * @author Inderjeet Singh * @author Joel Leitch */
@Documented @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.FIELD, ElementType.TYPE}) public @interface Since {
the value indicating a version number since this member or type has been present.
/** * the value indicating a version number since this member * or type has been present. */
double value(); }