/*
|
* 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 cn.emay.sdk.util.json.gson.annotations;
|
|
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 until a member or a type
|
* should be present. Basically, if Gson is created with a version number that
|
* exceeds the value stored in the {@code Until} annotation then the field will
|
* be ignored from the JSON output. 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;
|
* @Until(1.1) private String emailAddress;
|
* @Until(1.1) private String password;
|
* }
|
* </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(1.2).create()} then the
|
* {@code toJson()} and {@code fromJson()} methods of Gson will exclude the
|
* {@code emailAddress} and {@code password} fields from the example above,
|
* because the version number passed to the GsonBuilder, {@code 1.2}, exceeds
|
* the version number set on the {@code Until} annotation, {@code 1.1}, for
|
* those fields.
|
*
|
* @author Inderjeet Singh
|
* @author Joel Leitch
|
* @since 1.3
|
*/
|
@Retention(RetentionPolicy.RUNTIME)
|
@Target({ ElementType.FIELD, ElementType.TYPE })
|
public @interface Until {
|
|
/**
|
* the value indicating a version number until this member or type should be
|
* ignored.
|
*/
|
double value();
|
}
|
