3.3.1增强类型
前置增强：org.springframework.aop.MethodBeforeAdvice
后置增强：org.springframework.aop.AfterReturningAdvice
环绕增强：org.aopalliance.intercept.MethodInterceptor
异常抛出增强：org.springframework.aop.ThrowsAdvice
引介增强：org.springframework.aop.support.DelegatingIntroductionInterceptor
3.3.2前置增强
就是在连接点方法执行之前执行的内容。
如：我们在UserDaoImpl的save()方法执行之前执行一些内容。
a、UserDao与UserDaoImpl:
- public interface UserDao {
- public void save();
- }
- public class UserDaoImpl implements UserDao {
- public void save() {
- System.out.println("保存用户...");
- }
- }
public class UserDaoBeforeAdvice implements MethodBeforeAdvice {
public void before(Method method, Object[] args, Object object)
throws Throwable {
System.out.println("我是前置增强");
}
}
c、配置
<!-- 把增强类交由spring管理 --> <bean id="userDaoBeforeAdvice" class="cn.framelife.spring.advice.UserDaoBeforeAdvice"></bean> <!-- 把目标类交由spring管理 --> <bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <!-- 设置代理类 p:target-ref 目标对象 p:proxyInterfaces 代理所要实现的接口，也就是目标对象的接口 p:interceptorNames 织入的增强Bean，可以是多个，用","号分开 --> <bean id="adviceUserDao" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="cn.framelife.spring.dao.UserDao" p:interceptorNames="userDaoBeforeAdvice" p:target-ref="userDao" />
d、main方法中测试
ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
//通过代理来获取userDao对象
UserDao userDao = (UserDao) context.getBean("adviceUserDao");
userDao.save();
f、结果
我是前置增强 保存用户...
3.3.3后置增强
就是在连接点方法执行之后执行的内容。
a、UserDao与UserDaoImpl:
- public interface UserDao {
- public void save();
- }
- public class UserDaoImpl implements UserDao {
- public void save() {
- System.out.println("保存用户...");
- }
- }
public class UserDaoAfterAdvice implements AfterReturningAdvice {
@Override
public void afterReturning(Object object, Method method, Object[] args,
Object arg3) throws Throwable {
System.out.println("我是后置增强");
}
}
c、配置
<bean id="userDaoBeforeAdvice" class="cn.framelife.spring.advice.UserDaoBeforeAdvice"></bean> <bean id="userDaoAfterAdvice" class="cn.framelife.spring.advice.UserDaoAfterAdvice"></bean> <bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <bean id="adviceUserDao" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="cn.framelife.spring.dao.UserDao" p:interceptorNames="userDaoBeforeAdvice,userDaoAfterAdvice" p:target-ref="userDao" />
d、main方法中测试
ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
//通过代理来获取userDao对象
UserDao userDao = (UserDao) context.getBean("adviceUserDao");
userDao.save();
f、结果
保存用户... 我是后置增强
3.3.4环绕增强
环绕增强与struts2的AOP类似。
a、UserDao与UserDaoImpl:
- public interface UserDao {
- public void save();
- }
- public class UserDaoImpl implements UserDao {
- public void save() {
- System.out.println("保存用户...");
- }
- }
public class UserDaoSurroundAdvice implements MethodInterceptor {
@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
System.out.println("环绕增强在方法前执行...");
Object object = invocation.proceed();
System.out.println("环绕增强在方法后执行...");
return object;
}
}
c、配置
<bean id="userDaoSurroundAdvice" class="cn.framelife.spring.advice.UserDaoSurroundAdvice"></bean> <bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <bean id="adviceUserDao" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="cn.framelife.spring.dao.UserDao" p:interceptorNames=" userDaoSurroundAdvice" p:target-ref="userDao" />
d、main方法中测试
ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
//通过代理来获取userDao对象
UserDao userDao = (UserDao) context.getBean("adviceUserDao");
userDao.save();
f、结果
环绕增强在方法前执行... 保存用户... 环绕增强在方法后执行...
3.3.5异常抛出增强
就是在方法出现异常之后执行的代码。
a、UserDao与UserDaoImpl:
- public interface UserDao {
- public void save();
- }
public class UserDaoImpl implements UserDao {
public void save() {
System.out.println("保存用户...");
//使方法在运行的时候抛出一个异常
throw new RuntimeException("运行时异常...");
}
}
public class UserDaoThrowsAdvice implements ThrowsAdvice {
public void afterThrowing(Method method,Object[] args,Object taglet,Exception ex)throws Throwable{
System.out.println("我是异常抛出接口");
System.out.println(method.getName());
System.out.println(ex.getMessage());
}
}
c、配置
<bean id="userDaoThrowAdvice" class="cn.framelife.spring.advice.UserDaoThrowsAdvice"></bean> <!-- p:proxyTargetClass="false" 如果目标对象是一个类，而不是一个接口，我们设置为true --> <bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <bean id="adviceUserDao" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="cn.framelife.spring.dao.UserDao" p:interceptorNames="userDaoThrowAdvice" p:target-ref="userDao" p:proxyTargetClass="false" />
d、main方法中测试
ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
//通过代理来获取userDao对象
UserDao userDao = (UserDao) context.getBean("adviceUserDao");
userDao.save();
f、结果
保存用户... Exception in thread "main" java.lang.RuntimeException: 运行时异常... at cn.framelife.spring.dao.impl.UserDaoImpl.save(UserDaoImpl.java:12) at cn.framelife.spring.dao.impl.UserDaoImpl$$FastClassByCGLIB$$18bd6dee.invoke(<generated>) at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:191) at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:688) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150) at org.springframework.aop.framework.adapter.ThrowsAdviceInterceptor.invoke(ThrowsAdviceInterceptor.java:124)我是异常抛出接口 save 运行时异常... at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172) at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:621) at cn.framelife.spring.dao.impl.UserDaoImpl$$EnhancerByCGLIB$$5bbe38b0.save(<generated>) at cn.framelife.spring.test.Test.main(Test.java:17)
3.3.6引介增强
引介增强是为目标类创建新的方法和属性，引介增强的连接点是类级别的，不是方法级别的。通过引介增强，我们可以为目标类添加一个接口的实现，即原来目标类未实现某个接口，通过引介增强可以为目标类创建实现某个接口的代理。
a、UserDao与UserDaoImpl:
- public interface UserDao {
- public void save();
- }
- public class UserDaoImpl implements UserDao {
- public void save() {
- System.out.println("保存用户...");
- }
- }
public interface AInterface {
public void say();
}
c、增强类继承
DelegatingIntroductionInterceptor实现
AInterface
public class IntroductionAdvice extends DelegatingIntroductionInterceptor implements AInterface {
/*
* 实现AInterface中的方法
*/
public void say() {
System.out.println("UserDao要说话");
}
/*
* 重写DelegatingIntroductionInterceptor的invoke方法
*/
public Object invoke(MethodInvocation mi) throws Throwable {
System.out.println("方法执行前执行");
System.out.println(mi.getClass().getName());
System.out.println(mi.getMethod().getName());
Object object = super.invoke(mi);
System.out.println("方法执行后执行");
return object;
}
}
d、配置
<bean id="userDao" class="cn.framelife.spring.dao.impl.UserDaoImpl"></bean> <bean id="introductionAdvice" class="cn.framelife.spring.advice.IntroductionAdvice"></bean> <!-- 代理类设置 p:proxyTargetClass="true" 引介增强一定要通过创建子类来生成代理，所以要设置为true。 也不需要配置p:proxyInterfaces目标类的接口 p:interfaces 引介增强所实现的接口 --> <bean id="aProxy" class="org.springframework.aop.framework.ProxyFactoryBean" p:interfaces="cn.framelife.spring.dao.AInterface" p:interceptorNames="introductionAdvice" p:target-ref="userDao" p:proxyTargetClass="true" />
e、main方法中测试
ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml"});
UserDao userDao = (UserDao) context.getBean("aProxy");
userDao.save();
System.out.println("-------------");
AInterface a = (AInterface)userDao;
a.say();
System.out.println("-------------");
userDao.save();
f、结果
方法执行前执行 org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation save 保存用户... 方法执行后执行 ------------- 方法执行前执行 org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation say UserDao要说话 方法执行后执行 ------------- 方法执行前执行 org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation save 保存用户... 方法执行后执行
