Java Reflection Method Parameter getMethod(Class declaringType, String methodName, Class... parameterTypes)

Description

Finds a method by name and parameter types.

License

Apache License

Parameter

Parameter	Description
declaringType	the name of the class
methodName	the name of the method to look for
parameterTypes	the types of the parameters

Declaration

public static Method getMethod(Class<?> declaringType, String methodName, Class<?>... parameterTypes) 

Method Source Code

//package com.java2s;
/* 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./* w ww .j a v a  2  s .c o m*/
 */

import java.lang.reflect.Method;

public class Main {
    /**
     * Finds a method by name and parameter types.
     *
     * @param declaringType the name of the class
     * @param methodName the name of the method to look for
     * @param parameterTypes the types of the parameters
     */
    public static Method getMethod(Class<?> declaringType, String methodName, Class<?>... parameterTypes) {
        return findMethod(declaringType, methodName, parameterTypes);
    }

    private static Method findMethod(Class<? extends Object> clazz, String methodName, Object[] args) {
        for (Method method : clazz.getDeclaredMethods()) {
            // TODO add parameter matching
            if (method.getName().equals(methodName) && matches(method.getParameterTypes(), args)) {
                return method;
            }
        }
        Class<?> superClass = clazz.getSuperclass();
        if (superClass != null) {
            return findMethod(superClass, methodName, args);
        }
        return null;
    }

    private static boolean matches(Class<?>[] parameterTypes, Object[] args) {
        if ((parameterTypes == null) || (parameterTypes.length == 0)) {
            return ((args == null) || (args.length == 0));
        }
        if ((args == null) || (parameterTypes.length != args.length)) {
            return false;
        }
        for (int i = 0; i < parameterTypes.length; i++) {
            if ((args[i] != null) && (!parameterTypes[i].isAssignableFrom(args[i].getClass()))) {
                return false;
            }
        }
        return true;
    }
}

Related

1. getMethod(Class clazz, String name, Class... parameterTypes)
2. getMethod(Class clazz, String name, Class[] parameterTypes)
3. getMethod(Class cls, String name, Class... parameterTypes)
4. getMethod(Class clz, String methodName, Class... parameterTypes)
5. getMethod(Class declaringClass, String name, Class... parameterTypes)
6. getMethod(Class instance, String method, Class... parameters)
7. getMethod(Class sourceClass, boolean isFindDeclaredMethod, boolean isUpwardFind, String methodName, Class... methodParameterTypes)
8. getMethod(Class target, String methodName, Class... parameterTypes)
9. getMethod(Class type, String name, Class... parametersType)