java利用反射为接口实例化对象并调用

java利用反射为接口实例化对象并调用

package xxxxx;

import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import xxxxx.MyLibrary.MyCallback;

import java.lang.reflect.InvocationHandler;

class MyLibrary {
    public interface MyCallback {
        void doMyCallback();
    }
    public void mainMethod(MyCallback myCallback) {
        System.out.println("doing MyLibrary mainMethod...");
        myCallback.doMyCallback();
    }
}
class MyHandler implements InvocationHandler{
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("doing MyHandler invoke...");
        return null;
    }
}
public class Test3 {
    public static void main(String[] args) throws Exception {
    	Class<?> myLibraryClazz = Class.forName("xxxxx.MyLibrary");//类
        Class<?> myCallbackClazz = Class.forName("xxxxx.MyLibrary$MyCallback");//接口
        
        MyHandler myHandler = new MyHandler();//类
        MyCallback myCallback = (MyCallback)Proxy.newProxyInstance(
        		Test3.class.getClassLoader(),//类加载器
        		new Class[] { myCallbackClazz },//接口数组
        		myHandler//为接口实现的对应具体方法
        	);//为接口实例化对象
        Method method = myLibraryClazz.getDeclaredMethod("mainMethod", MyCallback.class);//（类名，参数类型）
        method.invoke(myLibraryClazz.newInstance(), myCallback);//调用方法，（实例化对象，内部接口实现对象）
    }
}

 运行结果：

doing MyLibrary mainMethod...
doing MyHandler invoke...