Spring3.x教程(二) Spring AOP

public class User {
    private Integer id;
    private String name;
}

public class UserDao {
    public void save(User user){
        System.out.println("save user....");
    }
    
    public void delete(int id){
        System.out.println("delete user....");
    }
    
    public void update(User user) {
        System.out.println("update user ....");
    }
    
    public User query(String name) {
        System.out.println("getUser ....");
        return new User();
    }
}

<?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-3.2.xsd">
    <bean id="userDaoTarget" class="com.boya.spring.dao.UserDao" />
    <bean id="userBeforeAdvice" class="com.boya.spring.aop.UserBeforeAdvice" />
    <bean id="userAfterAdvice" class="com.boya.spring.aop.UserAfterAdvice" />
    <bean id="userAroundAdvice" class="com.boya.spring.aop.UserAroundAdvice" />
    <bean id="userDao" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="interceptorNames">
            <list><value>userAroundAdvice</value></list>
        </property>
        <property name="target" ref="userDaoTarget"></property>
    </bean>
</beans>

public static void main(String[] args) {
    ApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
    UserDao userDao = context.getBean("userDao", UserDao.class);
    userDao.save(new User());
}

public interface SignInterface {
    public Object sign(String nameList);
}

public   class  Teacher  implements  SignInterface {
     public  Object sign(String nameList) {
        System. out .println( "Teacher sign..." );
         return   new  Object();
    }
}

public class Leader implements SignInterface {
    private Teacher teacher;
    public Object sign(String nameList) {
        if (teacher == null) {
            teacher = new Teacher();
        }
        Object o = teacher.sign(nameList);
        return o;
    }
}

public static void main(String[] args) {
    SignInterface s = new Leader();
    s.sign("names");
}

public class ProxyObject implements InvocationHandler {
    private Object proxy_obj;
    ProxyObject(Object obj) {
        this.proxy_obj = obj;
    }
    public static Object getProxy(Object obj) {
        Class cls = obj.getClass();
        // 通过Proxy类的newProxyInstance方法来返回代理对象
        return Proxy.newProxyInstance(cls.getClassLoader(), cls.getInterfaces(), new ProxyObject(obj));
    }
    /**
     * 实现InvocationHandler接口的invoke
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("调用方法:" + method + "()之前拦截处理");
        if (args != null) {
            System.out.println("方法有" + args.length + "个参数");
            for (int i = 0; i < args.length; i++) {
                System.out.println(args[i]);
            }
        }
        // 利用反射机制动态调用真实对象的方法
        Object o = method.invoke(proxy_obj, args);
        System.out.println("调用方法:" + method + "()之后拦截处理");
        return o;
    }
    // 测试代码
    public static void main(String agr[]) {
        SignInterface si = (SignInterface) getProxy(new Teacher());
        si.sign("names");
    }
}

public class CGLibTeacher {
    public Object sign(String nameList) {
        System.out.println("Teacher sign...");
        return new Object();
    }
}

public class CGLibAop implements MethodInterceptor {
        public Object intercept(Object arg0, Method arg1, Object[] arg2,   
                MethodProxy arg3) throws Throwable {   
            System.out.println("before...");
            Object o = arg3.invokeSuper(arg0, arg2);
            System.out.println("after...");
            return o;
        }   
}

public class CGLibProxy {
    public static CGLibTeacher create(CGLibAop aop){
        Enhancer en = new Enhancer();   
        //进行代理  
        en.setSuperclass(CGLibTeacher.class);   
        en.setCallback(aop);   
        //生成代理实例  
        return (CGLibTeacher)en.create();   
    }
    
    public static void main(String[] args) {
        CGLibTeacher t = CGLibProxy.create(new CGLibAop());
        t.sign("names");
    }
}