第六种方式
-
自动代理
IUserService.java
public interface IUserService {
/**
* 获取所有的用户对象列表
* @return
*/
List<Object> getAllUser();
/**
* 保存用户
* @param user
* @return
*/
boolean saveUser(Object user);
/**
* 根据用户uid删除该uid对应的用户信息
* @param uid
* @return
*/
boolean deleteUser(int uid);
/**
* 更新指定用户信息
* @param obj
* @return
*/
boolean updateUser(Object obj);
void getUserByUid();
}
UserServiceImpl.java
@Component("us")
public class UserServiceImpl implements IUserService {
@Override
public List<Object> getAllUser() {
System.out.println("--------getAllUser----------");
return new ArrayList<>();
}
@Override
public boolean saveUser(Object user) {
System.out.println("--------saveUser----------");
return true;
}
@Override
public boolean deleteUser(int uid) {
System.out.println("--------deleteUser----------");
return false;
}
@Override
public boolean updateUser(Object obj) {
System.out.println("--------updateUser----------");
return true;
}
@Override
public void getUserByUid() {
System.out.println("--------getUserByUid----------");
String str = null;
System.out.println(str.length());
}
}
MyAspect.java
/**
* 以注解的方式实现的切面类MyAspect
* 当前类中的五种通知方式均以注解方式完成
*/
@Component// 标注当前类为一个组件
@Aspect// 标注当前类为一个切面类
public class MyAspect {
/**
* @Pointcut 注解为了避免相同的匹配规则被定义多处，专门定义该方法设置执行的匹配规则，各个自行调用即可
* write once， only once
*/
@Pointcut(value = "execution(* com.aop6.*.*(..))")
public void setAll(){}
/**
* @Before 表示该方法为一个前置通知
* @param jp 连接点
*/
@Before("setAll()")
public void myBefore(JoinPoint jp){
//System.out.println(jp.getArgs());
System.out.println("this is before.");
}
/**
* @After 表示该方法为一个后置通知
* @param jp 连接点
*/
@After("setAll()")
public void myAfter(JoinPoint jp){
//System.out.println(jp.getArgs());
System.out.println("this is after.");
}
/**
* @Around 表示该方法为一个环绕通知
* @param pjp 处理连接点
* @return 返回每个业务方法的返回值
*/
@Around("setAll()")
public Object myAround(ProceedingJoinPoint pjp){
Object obj = null;
try {
System.out.println("this is around before");
obj = pjp.proceed();
System.out.println("this is around after");
} catch (Throwable throwable) {
throwable.printStackTrace();
}
return obj;
}
/**
* @AfterReturning 表示该方法为一个带有返回值的通知
* @param jp 连接点
* @param obj 业务方法的返回值
*/
@AfterReturning(value = "setAll()", returning = "obj")
public void myReturn(JoinPoint jp, Object obj){
System.out.println("this is after returnning " + obj);
}
/**
* @AfterThrowing 表示该方法为一个带有异常的通知
* @param jp 连接点
* @param e Throwable对象
*/
@AfterThrowing(value = "setAll()", throwing = "e")
public void myThrowing(JoinPoint jp, Throwable e){
System.out.println("this is after throwing " + e.getMessage());
}
}
TestAOP6.java
public class TestAOP6 {
@Test
public void testAOP6(){
ApplicationContext ac = new ClassPathXmlApplicationContext("com/aop6/beans.xml");
IUserService us = ac.getBean("us", IUserService.class);
us.getAllUser();
us.deleteUser(1);
us.saveUser("LKT");
us.updateUser("GOD");
us.getUserByUid();
}
}
beans.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.aop6" />
<aop:aspectj-autoproxy />
</beans>
- context:component-scan 组件扫描
- base-package指定要扫描的包的路径
- aop:aspectj-autoproxy标签实现自动代理
第七种方式
-
使用BeanPostProcessor方式实现Spring的AOP
IUserService.java
public interface IUserService {
/**
* 获取所有的用户对象列表
* @return
*/
List<Object> getAllUser();
/**
* 保存用户
* @param user
* @return
*/
boolean saveUser(Object user);
/**
* 根据用户uid删除该uid对应的用户信息
* @param uid
* @return
*/
boolean deleteUser(int uid);
/**
* 更新指定用户信息
* @param obj
* @return
*/
boolean updateUser(Object obj);
void getUserByUid();
}
UserServiceImpl.java
@Component("us")
public class UserServiceImpl implements IUserService {
@Override
public List<Object> getAllUser() {
System.out.println("--------getAllUser----------");
return new ArrayList<>();
}
@Override
public boolean saveUser(Object user) {
System.out.println("--------saveUser----------");
return true;
}
@Override
public boolean deleteUser(int uid) {
System.out.println("--------deleteUser----------");
return false;
}
@Override
public boolean updateUser(Object obj) {
System.out.println("--------updateUser----------");
return true;
}
@Override
public void getUserByUid() {
System.out.println("--------getUserByUid----------");
String str = null;
System.out.println(str.length());
}
}
UserServiceImpl2.java
//@Component("us2")
public class UserServiceImpl2 implements IUserService {
@Override
public List<Object> getAllUser() {
System.out.println("--------getAllUser----------");
return new ArrayList<>();
}
@Override
public boolean saveUser(Object user) {
System.out.println("--------saveUser----------");
return true;
}
@Override
public boolean deleteUser(int uid) {
System.out.println("--------deleteUser----------");
return false;
}
@Override
public boolean updateUser(Object obj) {
System.out.println("--------updateUser----------");
return true;
}
@Override
public void getUserByUid() {
System.out.println("--------getUserByUid----------");
System.out.println(1 / 0);
String str = null;
System.out.println(str.length());
}
}
MyBeanPostProcessor.java
- 配置了包扫描之后，该类会初始化两个对象EventListenerMethodProcessor和DefaultEventListenerFactory，再外加组件对象，所以会发现有三个before打印
public class MyBeanPostProcessor implements BeanPostProcessor {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
System.out.println("this is before " + bean);
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
System.out.println("this is after");
return Proxy.newProxyInstance(MyBeanPostProcessor.class.getClassLoader(), bean.getClass().getInterfaces(), new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
MyAspect ma = new MyAspect();
ma.before();
Object obj = method.invoke(bean, args);
ma.after();
return obj;
}
});
}
}
MyAspect.java - 自定义切面类
/**
* 分别有前置方法和后置方法
*/
public class MyAspect {
public void before(){
System.out.println("this is my aspect before");
}
public void after(){
System.out.println("this is my aspect after");
}
}
beans.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!--<bean id="us" class="com.aop7.UserServiceImpl" />-->
<!-- base-package指定要扫描的包为com.aop7 -->
<context:component-scan base-package="com.aop7" />
<bean class="com.aop7.MyBeanPostProcessor" />
</beans>
- context:component-scan上下文的组件扫描 base-package指定要扫描的包
指定BeanPostProcessor的Factory hook，让每个bean对象初始化是自动回调该对象中的回调方法
用良心做教育的qianfen学员
