Spring使用CGLIB动态代理-----Spring框架

我就是我 2024-03-24 18:05 86阅读 0赞

>     package com.powernode.proxy.client;
>     
>     import com.powernode.proxy.service.TimerMethodInterceptor;
>     import com.powernode.proxy.service.UserService;
>     import net.sf.cglib.proxy.Enhancer;
>     
>     public class Client
>     {
>         public static void main(String[] args)
>         {
>             //创建字节码生成器对象
>             //这个对象是CGLIB的核心对象,就是靠它生成代理类的
>             Enhancer enhancer = new Enhancer();
>             //告诉CGLIB父类对象是谁,谁需要代理
>             enhancer.setSuperclass(UserService.class);
>             //设置回调,这一步相当于JDK动态代理的InvocationHandler(调用处理器)
>             enhancer.setCallback(new TimerMethodInterceptor());
>             //创建代理对象
>             //子类这个代理类一定是UserService对象
>             UserService userService = (UserService)enhancer.create();
>             //这一步会做两件事,在内存中生成UserService的子类,即类的字节码
>             //创建代理对象
>             //代理对象的代理方法,在CGLIB中不是InvocationHandler接口
>             //是MethodInterception接口(方法拦截器接口)
>             boolean admin = userService.login("admin", "123");
>             System.out.println(admin ? "登陆成功" : "登陆失败");
>             userService.logOut();
>             //推荐记忆CGLIB动态代理的对象名字格式
>             //根据名字可以判断是否使用了CGLIB动态代理
>             System.out.println(userService);
>             //com.powernode.proxy.service.UserService$$EnhancerByCGLIB$$82cb55e3@45385f75
>             //底层本质com.powernode.proxy.service.UserService$$EnhancerByCGLIB$$82cb55e3继承了UserService方法
>         }
>     }
> 
>     package com.powernode.proxy.client;
>     
>     import com.powernode.proxy.service.TimerMethodInterceptor;
>     import com.powernode.proxy.service.UserService;
>     import net.sf.cglib.proxy.Enhancer;
>     
>     public class Client
>     {
>         public static void main(String[] args)
>         {
>             //创建字节码生成器对象
>             //这个对象是CGLIB的核心对象,就是靠它生成代理类的
>             Enhancer enhancer = new Enhancer();
>             //告诉CGLIB父类对象是谁,谁需要代理
>             enhancer.setSuperclass(UserService.class);
>             //设置回调,这一步相当于JDK动态代理的InvocationHandler(调用处理器)
>             enhancer.setCallback(new TimerMethodInterceptor());
>             //创建代理对象
>             //子类这个代理类一定是UserService对象
>             UserService userService = (UserService)enhancer.create();
>             //这一步会做两件事,在内存中生成UserService的子类,即类的字节码
>             //创建代理对象
>             //代理对象的代理方法,在CGLIB中不是InvocationHandler接口
>             //是MethodInterception接口(方法拦截器接口)
>             boolean admin = userService.login("admin", "123");
>             System.out.println(admin ? "登陆成功" : "登陆失败");
>             userService.logOut();
>             //推荐记忆CGLIB动态代理的对象名字格式
>             //根据名字可以判断是否使用了CGLIB动态代理
>             System.out.println(userService);
>             //com.powernode.proxy.service.UserService$$EnhancerByCGLIB$$82cb55e3@45385f75
>             //底层本质com.powernode.proxy.service.UserService$$EnhancerByCGLIB$$82cb55e3继承了UserService方法
>         }
>     }

>     package com.powernode.proxy.service;
>     
>     import net.sf.cglib.proxy.MethodInterceptor;
>     import net.sf.cglib.proxy.MethodProxy;
>     import org.slf4j.Logger;
>     import org.slf4j.LoggerFactory;
>     
>     import java.lang.reflect.Method;
>     
>     public class TimerMethodInterceptor implements MethodInterceptor
>     {
>         private static final Logger logger = LoggerFactory.getLogger(TimerMethodInterceptor.class);
>         @Override
>         public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
>             //前面增强
>             //怎么调用目标对象的目标方法
>             long begin = System.currentTimeMillis();
>             Object obj = methodProxy.invokeSuper(o,objects);
>             long end = System.currentTimeMillis();
>             long time = end - begin;
>             //后面增强
>             logger.info("耗时" + time);
>             return obj;
>         }
>     }
> 
>     package com.powernode.proxy.service;
>     
>     import net.sf.cglib.proxy.MethodInterceptor;
>     import net.sf.cglib.proxy.MethodProxy;
>     import org.slf4j.Logger;
>     import org.slf4j.LoggerFactory;
>     
>     import java.lang.reflect.Method;
>     
>     public class TimerMethodInterceptor implements MethodInterceptor
>     {
>         private static final Logger logger = LoggerFactory.getLogger(TimerMethodInterceptor.class);
>         @Override
>         public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
>             //前面增强
>             //怎么调用目标对象的目标方法
>             long begin = System.currentTimeMillis();
>             Object obj = methodProxy.invokeSuper(o,objects);
>             long end = System.currentTimeMillis();
>             long time = end - begin;
>             //后面增强
>             logger.info("耗时" + time);
>             return obj;
>         }
>     }

>     package com.powernode.proxy.service;
>     
>     import org.slf4j.Logger;
>     import org.slf4j.LoggerFactory;
>     import org.springframework.stereotype.Service;
>     
>     @Service
>     public class UserService
>     {
>         private static final Logger logger = LoggerFactory.getLogger(UserService.class);
>         //目标方法
>         public boolean login(String username,String password)
>         {
>             logger.info("系统正在验证目标身份");
>             if("admin".equals(username) && "123".equals(password))
>             {
>                 return true;
>             }
>             return false;
>         }
>         public void logOut()
>         {
>             logger.info("系统正在退出当前帐号");
>         }
>     }
> 
>     package com.powernode.proxy.service;
>     
>     import org.slf4j.Logger;
>     import org.slf4j.LoggerFactory;
>     import org.springframework.stereotype.Service;
>     
>     @Service
>     public class UserService
>     {
>         private static final Logger logger = LoggerFactory.getLogger(UserService.class);
>         //目标方法
>         public boolean login(String username,String password)
>         {
>             logger.info("系统正在验证目标身份");
>             if("admin".equals(username) && "123".equals(password))
>             {
>                 return true;
>             }
>             return false;
>         }
>         public void logOut()
>         {
>             logger.info("系统正在退出当前帐号");
>         }
>     }