NoOp.java

/*
 *  Copyright 2015. Hannes Dorfmann.
 *
 * 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.example.util.mvp.noop;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

import static java.lang.reflect.Proxy.newProxyInstance;

/**
 * Dynamically proxy to generate a new object instance for a given class by using reflections.
 *
 * @author Jens Dirller, taken from Mosby project (https://github.com/sockeqwe/mosby).
 * @since 1.2.0
 */
public final class NoOp {

    private static final InvocationHandler DEFAULT_VALUE = new DefaultValueInvocationHandler();

    private NoOp() {
        // no instances
    }

    @SuppressWarnings("unchecked")
    public static <T> T of(Class<T> interfaceClass) {

        return (T) newProxyInstance(interfaceClass.getClassLoader(), new Class[]{interfaceClass},
                DEFAULT_VALUE);
    }

    private static class DefaultValueInvocationHandler implements InvocationHandler {

        @Override
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

            return Defaults.defaultValue(method.getReturnType());
        }
    }

}