动态代理

package DynamicProxy;

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

interface AbstractClass {
    public void show();
}

class ClassA implements AbstractClass {
    public void show() {
        System.out.println("I am A !");
    }
}

class ClassB implements AbstractClass {
    public void show() {
        System.out.println("I am B !");
    }
}

class Invoker implements InvocationHandler {
    AbstractClass ac;
    public Invoker(AbstractClass ac) {
        this.ac = ac;
    }
    
    @Override
    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        method.invoke(ac, args);
        return null;
    }
    
}

public class DynamicProxyTest {
    public static void main(String[] args) {
        
        Invoker invoker1 = new Invoker(new ClassA());
        AbstractClass ac1 = (AbstractClass) Proxy.newProxyInstance(AbstractClass.class.getClassLoader(), new Class[] {AbstractClass.class}, invoker1);
        ac1.show();
        
        Invoker invoker2 = new Invoker(new ClassB());
        AbstractClass ac2 = (AbstractClass) Proxy.newProxyInstance(AbstractClass.class.getClassLoader(), new Class[] {AbstractClass.class}, invoker2);
        ac2.show();
    }
}