validate Retention Policy - Java java.lang.annotation

Java examples for java.lang.annotation:Retention

  1. HOME
  2. Java
  3. java.lang.annotation
  4. Retention

Description

validate Retention Policy

Demo Code

/*//from  w  w w  . j  av  a2 s  . c  o m
 * Copyright (c) 2008 Kasper Nielsen.
 *
 * 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.java2s;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

public class Main {
    public static <T> Class<T> validateRetentionPolicy(Class<T> c,
            RetentionPolicy policy) {
        Retention r = c.getAnnotation(Retention.class);
        if (r == null) {
            throw new IllegalArgumentException(
                    "Specified annotation type @"
                            + c.getSimpleName()
                            + " must have a runtime retention policy (@Retention(RetentionPolicy."
                            + policy
                            + "), but did not have any retention policy");
        } else if (r.value() != policy) {
            throw new IllegalArgumentException(
                    "Specified annotation type @"
                            + c.getSimpleName()
                            + " must have runtime retention policy (@Retention(RetentionPolicy.RUNTIME), but was "
                            + r.value());
        }
        return c;
    }
}

Related Tutorials