Spring AOP 代理模式学习

代理模式

代理是通知目标对象后创建的对象。从客户端的角度看，代理对象和目标对象是一样的。

静态代理

出租房屋

public interface Rent {     void Renthouse();}

房东类

public class Host implements Rent {    @Override    public void Renthouse() {        System.out.println("房东有一套房子出租!!!");    }}

代理类

public class Proxy implements Rent {    private Host host;        public Proxy(Host host) {        this.host = host;    }        @Override    public void Renthouse() {        host.Renthouse();        Money();        seeHose();        hetong();    }        public void Money() {        System.out.println("中介-收取一定的报酬会");    }        public void seeHose() {        System.out.println("中介-带我看房子。");    }        public void hetong() {        System.out.println("满意的话，签合同！");    }}

测试类

public class client {    public static void main(String[] args) {        Host host = new Host();        Proxy proxy = new Proxy(host);        proxy.Renthouse();    }}

动态代理

动态代理分为三大类：基于接口（JDK动态代理）、基于类（CGLIB动态代理）、Java字节码实现（Javassist）。

动态代理实现案例

public interface Rent {    void Rent();}

public class Host implements Rent {    @Override    public void Rent() {        System.out.println("房东有一整套房子出租!!!");    }}

public class ProxyInvocationHandler implements InvocationHandler {    private Rent rent;    public void setRent(Rent rent) {        this.rent = rent;    }    public Object getProxy() {        return Proxy.newProxyInstance(            this.getClass().getClassLoader(),            rent.getClass().getInterfaces(),            this        );    }    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {        return method.invoke(rent, args);    }}

public class client {    public static void main(String[] args) {        Host host = new Host();        ProxyInvocationHandler pih = new ProxyInvocationHandler();        pih.setRent(host);        Rent proxy = (Rent) pih.getProxy();        proxy.Rent();    }}