java有关静态代理及动态代理的实现

Posted 2020-12-25 盗帅_tim

public interface MyInterface {

    void doSomeThing();
    
    
    void someThingElse(String param);
}

public class RealObject implements MyInterface{

    @Override
    public void doSomeThing() {
        // TODO Auto-generated method stub
        print("开始调用doSomeThing方法");
        
    }

    @Override
    public void someThingElse(String param) {
        // TODO Auto-generated method stub
        print("开始调用somethingelse 方法；参数"+param);
        
    }

}

public class SimpleProxy implements MyInterface{
    
    private MyInterface myInterface;
    
    
    public SimpleProxy(MyInterface myInterface) {
        this.myInterface=myInterface;
    }

    @Override
    public void doSomeThing() {
        // TODO Auto-generated method stub
        print("业务逻辑dosomething...");
        myInterface.doSomeThing();
        
    }

    @Override
    public void someThingElse(String param) {
        // TODO Auto-generated method stub
        print("业务逻辑ELse...");
        myInterface.someThingElse(param);
        
    }
    
    public static void consumer(MyInterface myInterface) {
        
        myInterface.doSomeThing();
        myInterface.someThingElse("bubu..");
    }
    
    public static void main(String[] args) {
        consumer(new RealObject());
        consumer(new SimpleProxy(new RealObject()));
    }

}

以下是动态代理

 

自定义一个调用处理器：

/**
 * 调用处理器<P>
*  动态代理能把所有调用都重定向到调用处理器上
*/
public class DynamicProxyHandle implements InvocationHandler{

    private Object proxied;
    
    public DynamicProxyHandle(Object object) {
        this.proxied=object;
    }
    
    @Override
    public Object invoke(Object proxy,Method method,Object[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
        print("proxy class:"+proxy.getClass()+" method:"+method+" args:"+args);
        
        if(method.getName().equals("doSomeThing")) {
            print("代理检测到doSomeThing被调用");
        }
//        if(args!=null) {
//            for(Object object:args) {
//                print("====="+object);
//            }
//        }
        
        
        
        return method.invoke(proxied, args);
    }

}

public class SimpleDynamicProxy {

    public static void consumer(MyInterface myInterface) {

        myInterface.doSomeThing();
        myInterface.someThingElse("bubu..");
    }

    public static void main(String[] args) {
        RealObject realObject = new RealObject();

        consumer(realObject);
        print("-----------------------------------------");
        /**
         * 1.一个类加载器【你通常可以从已经被加载的类对象中获取得到其类加载器，然后传递给它】
         * 2.希望该代理实现的接口列表【不是类或抽象类】
         * 3.以及InvocationHandler的一个实现（一个调用处理器）
         */
        MyInterface dynamicProxy = (MyInterface) Proxy.newProxyInstance(MyInterface.class.getClassLoader(),
                new Class[]{MyInterface.class}, new DynamicProxyHandle(realObject));
        consumer(dynamicProxy);

    }
}