代理模式

静态代理

package com.bjsxt.proxy;

import com.bjsxt.service.SomeService;

//静态代理类，要和目标类实现相同接口
public class ServiceProxy implements SomeService {
    SomeService target;
    
    public ServiceProxy() {
        super();
    }
    

    public ServiceProxy(SomeService target) {
        super();
        this.target = target;
    }


    public String doSome(){
        return target.doSome().toUpperCase();
    }
}

package com.bjsxt.service;

//主业务接口
public interface SomeService {
    String doSome();
}

package com.bjsxt.service.impl;

import com.bjsxt.service.SomeService;

//目标类
public class SomeServiceImpl implements SomeService {
    
    
    public SomeServiceImpl() {
        System.out.println("无参构造器执行！");
    }

    @Override
    public String doSome() {
        return "China";
    }

}

package com.bjsxt.test;

import com.bjsxt.proxy.ServiceProxy;
import com.bjsxt.service.SomeService;
import com.bjsxt.service.impl.SomeServiceImpl;

public class SomeTest {
    public static void main(String[] args) {
        //定义目标对象
        SomeService target = new SomeServiceImpl();
        //定义目标对象的代理对象
        SomeService proxy = new ServiceProxy(target);
        String result = proxy.doSome();
        System.out.println(result);
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    <!-- bean的定义:以下配置相当于SomeService service = new SomeServiceImpl(); -->
    <bean id="someServiceImpl" class="com.bjsxt.service.impl.SomeServiceImpl"></bean>
</beans>

动态代理

分为：jdk动态代理和CGLIB动态代理

package com.bjsxt.test;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import com.bjsxt.service.SomeService;
import com.bjsxt.service.impl.SomeServiceImpl;

public class SomeTest {
    public static void main(String[] args) {
        //定义目标对象
        final SomeService target = new SomeServiceImpl();
        //定义目标对象的代理对象
        SomeService proxy = (SomeService) Proxy.newProxyInstance(target.getClass().getClassLoader(),//目标类的类加载器
                                                    target.getClass().getInterfaces(),//目标类实现的所有接口
                                                    new InvocationHandler() {//调用处理器
                                                        //proxy:代理对象
                                                        //method:目标方法
                                                        //args:目标方法参数
                                                        @Override
                                                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                                                            String result = (String) method.invoke(target, args);
                                                            return result.toUpperCase();
                                                        }
                                                    });
        String result1 = proxy.doSome();
        System.out.println(result1);
    }
}