Call to get all the methods of a class that have the given annotation. - Java java.lang.annotation

Java examples for java.lang.annotation:Method Annotation

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Description

Call to get all the methods of a class that have the given annotation.

Demo Code

/**//from www  .  j ava2  s. co m
 * Copyright (C) 2011 Tom Spencer <thegaffer@tpspencer.com>
 *
 * This file is part of TAL.
 *
 * TAL is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * TAL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with TAL. If not, see <http://www.gnu.org/licenses/>.
 *
 * Note on dates: Year above is the year this code was built. This
 * project first created in 2008. Code was created between these two
 * years inclusive.
 */
//package com.java2s;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] argv) throws Exception {
        Class annotationType = String.class;
        Class cls = String.class;
        System.out.println(getAnnotatedMethods(annotationType, cls));
    }

    /**
     * Call to get all the methods of a class that have the given
     * annotation.
     * 
     * @param annotationType The annotation we want on the methods
     * @param cls The class to check
     * @return The methods and their annotation of the given type in a map (will be empty if nothing found)
     */
    public static <T extends Annotation> Map<Method, T> getAnnotatedMethods(
            Class<T> annotationType, Class<?> cls) {
        Map<Method, T> ret = new HashMap<Method, T>();

        Method[] methods = cls.getMethods();
        for (Method method : methods) {
            T annotation = method.getAnnotation(annotationType);
            if (annotation != null)
                ret.put(method, annotation);
        }

        return ret;
    }
}

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