jdk动态代理和cglib动态代理详解

/**

  * 业务实现类接口

  */

public interface orderservice {

     //减库存操作

     void reducestock();

}

/**

  * 业务实现类

  */

@slf4j

public class orderserviceimpl implements orderservice {

     @override

     public void reducestock() {

         try {

             log.info( "预减库存中……" );

             thread.sleep( 1000 );

         } catch (exception e){

             e.printstacktrace();

         }

     }

}

/**

  * 代理类

  */

@slf4j

public class orderservicelogproxy extends orderserviceimpl{

     @override

     public void reducestock() {

         log.info( "预减库存开始……" );

         super .reducestock();

         log.info( "预减库存结束……" );

     }

}

/**

  * 测试继承方式实现的静态代理

  */

@test

public void testorderserviceproxy(){

     orderservicelogproxy proxy = new orderservicelogproxy();

     proxy.reducestock();

}

/**

  * 聚合方式实现静态代理：代理类中引入业务类

  */

@slf4j

public class orderservicelogproxy2 implements orderservice {

     private orderserviceimpl orderservice;

     public orderservicelogproxy2(orderserviceimpl orderservice) {

         this .orderservice = orderservice;

     }

     @override

     public void reducestock() {

         log.info( "预减库存开始……" );

         orderservice.reducestock();

         log.info( "预减库存结束……" );

     }

}

/**

  * 测试聚合方式实现的静态代理

  */

@test

public void testorderserviceproxy2() {

     orderserviceimpl orderservice = new orderserviceimpl();

     orderservicelogproxy2 proxy2 = new orderservicelogproxy2(orderservice);

     proxy2.reducestock();

}

/**

  * 聚合方式实现静态代理--日志记录功能叠加改造

  */

@slf4j

public class orderservicelogproxy3 implements orderservice {

     //注意，这里换成了接口

     private orderservice orderservice;

     public orderservicelogproxy3(orderservice orderservice) {

         this .orderservice = orderservice;

     }

     @override

     public void reducestock() {

         log.info( "预减库存开始……" );

         orderservice.reducestock();

         log.info( "预减库存结束……" );

     }

}

/**

  * 聚合方式实现静态代理--日志记录功能叠加改造

  */

@slf4j

public class orderservicepermissionproxy implements orderservice {

     //注意，这里换成了接口

     private orderservice orderservice;

     public orderservicepermissionproxy(orderservice orderservice) {

         this .orderservice = orderservice;

     }

     @override

     public void reducestock() {

         log.info( "权限验证开始……" );

         orderservice.reducestock();

         log.info( "权限验证结束……" );

     }

}

/**

  * 测试聚合方式实现的静态代理-功能叠加

  */

@test

public void testorderserviceproxy3() {

     orderserviceimpl orderservice = new orderserviceimpl();

     orderservicelogproxy2 logproxy2 = new orderservicelogproxy2(orderservice);

     orderservicepermissionproxy permissionproxy = new orderservicepermissionproxy(logproxy2);

     permissionproxy.reducestock();

}

import lombok.extern.slf4j.slf4j;

import java.lang.reflect.invocationhandler;

import java.lang.reflect.method;

/**

  * jdk动态代理实现，必须实现invocationhandler接口

  * invocationhandler可以理解为事务处理器，所有切面级别的逻辑都在此完成

  */

@slf4j

public class dynamiclogproxy implements invocationhandler {

     //需要代理的对象类

     private object target;

     public dynamiclogproxy(object target) {

         this .target = target;

     }

     /**

      * @param obj    代理对象

      * @param method 对象方法

      * @param args   方法参数

      * @return

      * @throws throwable

      */

     @override

     public object invoke(object obj, method method, object[] args) throws throwable {

         log.info( "这里是日志记录切面，日志开始……" );

         //使用方法的反射

         object invoke = method.invoke(target, args);

         log.info( "这里是日志记录切面，日志结束……" );

         return invoke;

     }

}

/**

  * 测试jdk动态代理实现的日志代理类

  */

@test

public void testdynamiclogproxy() {

     orderserviceimpl orderservice = new orderserviceimpl();

     class <?> clazz = orderservice.getclass();

     dynamiclogproxy logproxyhandler = new dynamiclogproxy(orderservice);

     //通过proxy.newproxyinstance(类加载器, 接口s, 事务处理器handler) 加载动态代理

     orderservice os = (orderservice) proxy.newproxyinstance(clazz.getclassloader(), clazz.getinterfaces(), logproxyhandler);

     os.reducestock();

}

import lombok.extern.slf4j.slf4j;

import java.lang.reflect.invocationhandler;

import java.lang.reflect.method;

/**

  * 基于jdk动态代理实现的权限认证代理类

  */

@slf4j

public class dynamicpermissionproxy implements invocationhandler{

     private object target;

     public dynamicpermissionproxy(object target) {

         this .target = target;

     }

     /**

      * @param obj    代理对象

      * @param method 对象方法

      * @param args   方法参数

      * @return

      * @throws throwable

      */

     @override

     public object invoke(object obj, method method, object[] args) throws throwable {

         log.info( "这里是权限认证切面，开始验证……" );

         object invoke = method.invoke(target,args);

         log.info( "这里是权限认证切面，结束验证……" );

         return invoke;

     }

}

/**

  * 测试jdk动态代理实现的日志、权限功能代理类

  */

@test

public void testdynamiclogandpermissproxy() {

     orderserviceimpl orderservice = new orderserviceimpl();

     class <?> clazz = orderservice.getclass();

     dynamiclogproxy logproxyhandler = new dynamiclogproxy(orderservice);

     orderservice os = (orderservice) proxy.newproxyinstance(clazz.getclassloader(), clazz.getinterfaces(), logproxyhandler);

     //注：这里把日志代理类实例对象传入权限认证代理类中

     dynamicpermissionproxy dynamicpermissionproxy = new dynamicpermissionproxy(os);

     orderservice os2 = (orderservice)proxy.newproxyinstance(os.getclass().getclassloader(),os.getclass().getinterfaces(),dynamicpermissionproxy);

     os2.reducestock();

}

public class hashmapproxytest {

     public static void main(string[] args) {

         final hashmap<string, object> hashmap = new hashmap<>();

         map<string, object> mapproxy = (map<string, object>) proxy.newproxyinstance(hashmap. class .getclassloader(), hashmap. class .getinterfaces(), new invocationhandler() {

             @override

             public object invoke(object proxy, method method, object[] args) throws throwable {

                 return method.invoke(hashmap, args);

             }

         });

         mapproxy.put( "key1" , "value1" );

         system.out.println(mapproxy);

     }

}

<aop:aspectj-autoproxy proxy-target- class = "true" />

@enableaspectjautoproxy (proxytargetclass = true )

import lombok.extern.slf4j.slf4j;

import org.springframework.cglib.proxy.enhancer;

import org.springframework.cglib.proxy.methodinterceptor;

import org.springframework.cglib.proxy.methodproxy;

import java.lang.reflect.method;

/**

  * 基于cglib方式实现动态代理-日志功能

  * 它是针对类实现代理的，类不用实现接口，cglib对目标类产生一个子类，通过方法拦截技术拦截所有的方法调用

  */

@slf4j

public class dynamiccgliblogproxy implements methodinterceptor {

     private enhancer enhancer = new enhancer();

     public object getproxyobj( class clazz) {

         //设置父类

         enhancer.setsuperclass(clazz);

         enhancer.setcallback( this );

         enhancer.setusecache( false );

         return enhancer.create();

     }

     /**

      * 拦截所有目标类的方法调用

      *

      * @param o           目标对象

      * @param method      目标方法

      * @param args        方法参数

      * @param methodproxy 代理类实例

      * @return

      * @throws throwable

      */

     @override

     public object intercept(object o, method method, object[] args, methodproxy methodproxy) throws throwable {

         log.info( "这里是日志记录切面，日志开始……" );

         //代理类对象实例调用父类方法

         object result = methodproxy.invokesuper(o, args);

         log.info( "这里是日志记录切面，日志结束……" );

         return result ;

     }

}

/**

  * 测试cglib实现的动态代理-日志功能

  */

@test

public void testgclibdynamiclogproxy(){

     dynamiccgliblogproxy dynamiccgliblogproxy = new dynamiccgliblogproxy();

     orderserviceimpl orderservice = (orderserviceimpl)dynamiccgliblogproxy.getproxyobj(orderserviceimpl. class );

     orderservice.reducestock();

}

<dependency>

     <groupid>org.springframework</groupid>

     <artifactid>spring-core</artifactid>

     <version> 4.1 . 0 .release</version>

</dependency>

<dependency>

      <groupid>junit</groupid>

      <artifactid>junit</artifactid>

      <version> 4.11 </version>

      <scope>test</scope>

</dependency>