Java-动态代理

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1.代码

package com.che.carcheck.ui.helper;import com.che.carcheck.support.util.LogUtil;import net.sf.cglib.proxy.Enhancer;import net.sf.cglib.proxy.MethodInterceptor;import net.sf.cglib.proxy.MethodProxy;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import java.lang.reflect.Proxy;/** * 代理模式学习 * <p> * 作者：余天然 on 16/5/6 下午2:30 */public class ProxyStudy {    //使用场景    public static void main() {        //被代理类        UserImpl target = new UserImpl("小明");        target.login();        target.updateInfo();        //静态代理        testStaticProxy(target);        //JDK动态代理        testJdkProxy(target);        //Cglib动态代理        testCglibProxy(target);    }    private static void testStaticProxy(UserImpl target) {        LogUtil.print("静态代理:开始");        UserStaticProxy staticProxy = new UserStaticProxy(target);        staticProxy.login();        staticProxy.updateInfo();    }    private static void testJdkProxy(UserImpl target) {        LogUtil.print("JDK动态代理:开始");        JdkProxyFactory jdkFactory = new JdkProxyFactory();        User jdkProxy = (User) jdkFactory.createProxy(target);        jdkProxy.login();        jdkProxy.updateInfo();    }    /**     * 测试Cglib动态代理     * <p>     * 注意：此代码在Java环境可运行，但在Android环境会报错！     * 原因：Java是JVM虚拟器,Android是DarvikVM虚拟机,类加载机制有区别，而Cglib是基于继承的字节码生成技术，所有有问题。     *     * @param target     */    private static void testCglibProxy(UserImpl target) {        LogUtil.print("Cglib动态代理:开始");        CglibProxyFactory cglibFactory = new CglibProxyFactory();        User cglibProxy = (User) cglibFactory.createProxy(target);        cglibProxy.login();        cglibProxy.updateInfo();    }    //接口    public interface User {        void login();        void updateInfo();    }    //被代理类    public static class UserImpl implements User {        private String name;        public UserImpl(String name) {            this.name = name;        }        @Override        public void login() {            LogUtil.print(this.name + "登录……");        }        @Override        public void updateInfo() {            LogUtil.print(this.name + "更新信息……");        }    }    //静态代理    public static class UserStaticProxy implements User {        private UserImpl userImpl;        public UserStaticProxy(UserImpl userImpl) {            this.userImpl = userImpl;        }        @Override        public void login() {            doBefore();            this.userImpl.login();        }        @Override        public void updateInfo() {            doBefore();            this.userImpl.updateInfo();            doAfter();        }        private void doBefore() {            LogUtil.print("静态代理:前置动作……");        }        private void doAfter() {            LogUtil.print("静态代理:后置动作……");        }    }    //JDK动态代理    public static class JdkProxyFactory implements InvocationHandler {        private Object target;        //创建代理类        public Object createProxy(Object target) {            this.target = target;            //取得代理对象            return Proxy.newProxyInstance(                    target.getClass().getClassLoader(), target.getClass().getInterfaces(), this);        }        //改变委托类方法的调用逻辑        @Override        public Object invoke(Object proxy, Method method, Object[] args)                throws Throwable {            Object result = null;            if (method.getName().equals("login")) {                doBefore();                result = method.invoke(target, args);            }            if (method.getName().equals("updateInfo")) {                doBefore();                result = method.invoke(target, args);                doAfter();            }            return result;        }        private void doBefore() {            LogUtil.print("JDK动态代理:前置动作……");        }        private void doAfter() {            LogUtil.print("JDK动态代理:后置动作……");        }    }    //Cglib动态代理    public static class CglibProxyFactory implements MethodInterceptor {        private Object target;        //创建代理类        public Object createProxy(Object target) {            this.target = target;            Enhancer enhancer = new Enhancer();            enhancer.setSuperclass(this.target.getClass());            enhancer.setCallback(this);            return enhancer.create();        }        //改变委托类方法的调用逻辑        @Override        public Object intercept(Object target, Method method, Object[] args, MethodProxy proxy) throws Throwable {            Object result = null;            if (method.getName().equals("login")) {                doBefore();                result = proxy.invokeSuper(target, args);            }            if (method.getName().equals("updateInfo")) {                doBefore();                result = proxy.invokeSuper(target, args);                doAfter();            }            return result;        }        private void doBefore() {            LogUtil.print("Cglib动态代理:前置动作……");        }        private void doAfter() {            LogUtil.print("Cglib动态代理:后置动作……");        }    }}
2.日志

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