InvocationHandler接口
[java] public interface InvocationHandler{
public Object invoke(Object proxy,Method method,Object[] args)throws Throwable
}
public interface InvocationHandler{
public Object invoke(Object proxy,Method method,Object[] args)throws Throwable
}
参数说明：
Object proxy：被代理的对象
Method method：要调用的方法
Object args[]：方法调用时所需要的参数
Proxy类
Proxy类是专门完成代理的操作类，可以通过此类为一个或多个接口动态地生成实现类，此类提供了如下的操作方法：
[java] public static Object newProxyInstance(ClassLoader loader,
Class< >[] interfaces,
InvocationHandler h)
throws IllegalArgumentException
public static Object newProxyInstance(ClassLoader loader,
Class< >[] interfaces,
InvocationHandler h)
throws IllegalArgumentException参数说明：
ClassLoader loader：类加载器
Class< >[] interfaces：得到全部的接口
InvocationHandler h：得到InvocationHandler接口的子类实例
动态代理：
[java] package com.itmyhome;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
interface IHello{ //定义接口
public void sayHello();
}
class HelloImpl implements IHello{
@Override
public void sayHello() {
// TODO Auto-generated method stub
System.out.println("hello itmyhome");
}
}
class MyInvocationHandler implements InvocationHandler{
private Object obj; //真实主题类
public Object bind(Object obj){
this.obj = obj;
return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), this);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("***before***");
Object temp = method.invoke(obj, args);
System.out.println("***after***");
return temp;
}
}
public class T {
public static void main(String[] args) throws Exception{
IHello h = (IHello)new MyInvocationHandler().bind(new HelloImpl());
h.sayHello();
}
}
package com.itmyhome;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
interface IHello{ //定义接口
public void sayHello();
}
class HelloImpl implements IHello{
@Override
public void sayHello() {
// TODO Auto-generated method stub
System.out.println("hello itmyhome");
}
}
class MyInvocationHandler implements InvocationHandler{
private Object obj; //真实主题类
public Object bind(Object obj){
this.obj = obj;
return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), this);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("***before***");
Object temp = method.invoke(obj, args);
System.out.println("***after***");
return temp;
}
}
public class T {
public static void main(String[] args) throws Exception{
IHello h = (IHello)new MyInvocationHandler().bind(new HelloImpl());
h.sayHello();
}
}