java动态代理

编写Java动态代理的步骤如下：

 

1.创建一个实现接口InvocationHandler的类，它必须实现invoke方法

 

2.创建被代理的类以及接口

 

3.通过Proxy的静态方法 newProxyInstance(ClassLoader loader, Class[] interfaces, InvocationHandler h) 

 

 

 4.通过代理调用方法

package test;

public interface PeopleInfac {
    public void showInfo();

}

package test; public interface PeopleInfac { public void showInfo(); }

 

package test;

public class People implements PeopleInfac {

    public void showInfo() {

        System.out.println("people showInfo()");
    }

}

package test; public class People implements PeopleInfac { public void showInfo() { System.out.println("people showInfo()"); } }

 

package test;

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

public class DanimacProxy implements InvocationHandler {

    Object o;

    public DanimacProxy(Object o) {
        this.o = o;
    }

    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        method.invoke(o, null);
        return null;
    }
}

package test; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; public class DanimacProxy implements InvocationHandler { Object o; public DanimacProxy(Object o) { this.o = o; } public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { method.invoke(o, null); return null; } }

 

package test;

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

public class Test {

    public static void main(String[] args) {

        People p = new People();

        InvocationHandler proxy = new DanimacProxy(p);

        Class<?> cls = p.getClass();

        PeopleInfac pi = (PeopleInfac) Proxy.newProxyInstance(cls
                .getClassLoader(), cls.getInterfaces(), proxy);

        pi.showInfo();
    }
}