代理模式
代理模式 实现逻辑和实现的解耦
代理模式 为了提供额外的的操作，插入用来代替实际对象的对象。这些操作通常涉及与实际对象通信，代理充当中间人的角色
- 接口
/**
* 接口
*/
public interface Interface {
void doSomething();
void somethingElse(String arg);
}
- 实际对象
/**
* 实际对象
*/
public class RealObject implements Interface {
public void doSomething() {
System.out.println("doSomething");
}
public void somethingElse(String arg) {
System.out.println("somethingElse" + arg);
}
}
- 代理对象
/**
* 代理对象
*/
public class Proxy implements Interface {
private Interface proxied;
public Proxy(Interface proxied) {
this.proxied = proxied;
}
public void doSomething() {
System.out.println("Proxy doSomething");
proxied.doSomething();
}
public void somethingElse(String arg) {
System.out.println("Proxy somethingElse" + arg);
proxied.somethingElse(arg);
}
}
- 测试
/**
* 测试代理，比较原对象与代理对象
*
* @param args
*/
public static void main(String[] args) {
Interface iface = new RealObject();
iface.doSomething();
iface.somethingElse("bonobo");
Interface iface2 = new Proxy(iface);
iface2.doSomething();
iface2.somethingElse("bonobo");
}
动态代理
Java动态代理可以动态创建代理并动态处理对所代理的方法的调用
在动态里上所做的所有调用都会被重定向到单一的调用处理器上，它的工作是揭示调用的类型并确定对应的对策
- 动态代理
public class DynamicProxyHandler implements InvocationHandler {
private Object proxied;
public DynamicProxyHandler(Object proxied) {
this.proxied = proxied;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("**** proxy:" + proxy.getClass() + ".method: " + method + ".args: " + args);
if (args != null) {
for (Object arg : args) {
System.out.println(" " + args);
}
}
return method.invoke(proxied, args);
}
}
- 测试
public static void main(String[] args){
RealObject real = new RealObject();
real.doSomething();
real.somethingElse("bonobo");
Interface proxy = (Interface) Proxy.newProxyInstance(
Interface.class.getClassLoader(),
new Class[]{Interface.class},
new DynamicProxyHandler(real));
proxy.doSomething();
proxy.somethingElse("bonobo");
}
