一、代理模式：静态代理与动态代理

• 静态代理
• 动态代理

静态代理

• 注：实质就是使代理类和被代理类实现同一个接口，然后在代理类中添加其他操作。

• MyProxy.java文件

  package cn.qujialin.proxy;
  //代理类
  public class MyProxy implements Operator{
      private Operator operator;
  
      public MyProxy(Operator operator){
          this.operator = operator;
      }
  
      @Override
      public int add(int i, int j) {
          System.out.println("proxy前");
          operator.add(i,j);
          System.out.println("proxy后");
          return 0;
      }
  
      @Override
      public int sub(int i, int j) {
          System.out.println("proxy前");
          operator.sub(i,j);
          System.out.println("proxy后");
          return 0;
      }
  
      @Override
      public int mul(int i, int j) {
          System.out.println("proxy前");
          operator.mul(i,j);
          System.out.println("proxy后");
          return 0;
      }
  
      @Override
      public int div(int i, int j) {
          System.out.println("proxy前");
          operator.div(i,j);
          System.out.println("proxy后");
          return 0;
      }
  }
  //被代理类
  class MyOperator implements Operator{
      @Override
      public int add(int i, int j){
          System.out.println("add......");
          return i + j;
      }
      @Override
      public int sub(int i, int j){
          System.out.println("sub......");
          return i - j;
      }
      @Override
      public int mul(int i, int j){
          System.out.println("mul......");
          return i * j;
      }
      @Override
      public int div(int i, int j){
          System.out.println("div......");
          return i / j;
      }
  
  }
  
  

• Operato.java

  package cn.qujialin.proxy;
  //接口
  public interface Operator {
      public int add(int i, int j);
      public int sub(int i, int j);
      public int mul(int i, int j);
      public int div(int i, int j);
  }
  

• TestMain.java

  package cn.qujialin.proxy;
  //测试
  public class TestMain {
      public static void main(String[] args) {
          Operator op = new MyProxy(new MyOperator());
          op.add(1,2);
      }
  }
  

动态代理

• MyActiveProxyFactory.java

  package cn.qujialin.activeproxy;
  
  import java.lang.reflect.InvocationHandler;
  import java.lang.reflect.Method;
  import java.lang.reflect.Proxy;
  //代理工厂
  public class MyActiveProxyFactory {
  
      public static Object getProxyInstance(Operator op){
          Object proxy = null;
          ClassLoader cl = op.getClass().getClassLoader();
          Class[] interfaces = op.getClass().getInterfaces();
          InvocationHandler invocationHandler = new InvocationHandler() {
              @Override
              public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                  String methodName = method.getName();
                  System.out.println("methodName:::" + methodName);
                  Object result = method.invoke(op, args);
                  System.out.println("methodName:::" + methodName);
                  return result;
              }
          };
          return Proxy.newProxyInstance(cl,interfaces,invocationHandler);
      }
  
  }
  

• Operator.java

  package cn.qujialin.activeproxy;
  //接口
  public interface Operator {
      public int add(int i, int j);
      public int sub(int i, int j);
      public int mul(int i, int j);
      public int div(int i, int j);
  }
  

• MyOperator.java

  package cn.qujialin.activeproxy;
  
  import cn.qujialin.activeproxy.Operator;
  
  //被代理类
  public class MyOperator implements Operator{
      @Override
      public int add(int i, int j){
          System.out.println("add......");
          return i + j;
      }
      @Override
      public int sub(int i, int j){
          System.out.println("sub......");
          return i - j;
      }
      @Override
      public int mul(int i, int j){
          System.out.println("mul......");
          return i * j;
      }
      @Override
      public int div(int i, int j){
          System.out.println("div......");
          return i / j;
      }
  
  }
  
  

• TestMain.java

  package cn.qujialin.activeproxy;
  //测试
  public class TestMain {
      public static void main(String[] args) {
          Operator p = (Operator)MyActiveProxyFactory.getProxyInstance(new MyOperator());
          p.add(3,5);
      }
  }