在本教程中，我们将向你展示如何将AspectJ注解集成到Spring AOP框架。在这个Spring AOP+ AspectJ 示例中，让您轻松实现拦截方法。
常见AspectJ的注解：
1 @Before – 方法执行前运行
2 @After – 运行在方法返回结果后
3 @AfterReturning – 运行在方法返回一个结果后，在拦截器返回结果。
4 @AfterThrowing – 运行方法在抛出异常后，
5 @Around – 围绕方法执行运行，结合以上这三个通知。
注意
Spring AOP 中没有 AspectJ 支持，请阅读 内置 Spring AOP 例子。
1 公用类
package com.gp6.aop.aspectJ.annotation;
public interface CustomerBo {
void addCustomer();
String addCustomerReturnValue();
void addCustomerThrowException() throws Exception;
void addCustomerAround(String name);
}
package com.gp6.aop.aspectJ.annotation;
public class CustomerBoImpl implements CustomerBo {
public void addCustomer(){
System.out.println("addCustomer() is running ");
}
public String addCustomerReturnValue(){
System.out.println("addCustomerReturnValue() is running ");
return "abc";
}
public void addCustomerThrowException() throws Exception {
System.out.println("addCustomerThrowException() is running ");
throw new Exception("Generic Error");
}
public void addCustomerAround(String name){
System.out.println("addCustomerAround() is running, args : " + name);
}
}
2 公用配置文件----启用AspectJ
<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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">
<!-- 在 Spring 配置文件，把“<aop:aspectj-autoproxy />”，并定义Aspect(拦截)和普通的bean -->
<aop:aspectj-autoproxy />
<bean id="customerBo" class="com.gp6.aop.aspectJ.annotation.CustomerBoImpl" />
<!-- Aspect -->
<bean id="logAspect" class="com.gp6.aop.aspectJ.annotation.LoggingAspect" />
</beans>
3. AspectJ @Before
在下面例子中，logBefore()方法将在 customerBo接口的 addCustomer()方法的执行之前被执行。
AspectJ的“切入点”是用来声明哪种方法将被拦截，应该参考Spring AOP切入点指南，支持切入点表达式的完整列表。
package com.gp6.aop.aspectJ.annotation;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@Before("execution(* com.gp6.aop.aspectJ.annotation.CustomerBo.addCustomer(..))")
public void logBefore(JoinPoint joinPoint) {
System.out.println("logBefore() is running!================START");
System.out.println("hijacked : " + joinPoint.getSignature().getName());
System.out.println("logBefore() is running!================END");
}
}
package com.gp6.aop.aspectJ.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) throws Exception {
ApplicationContext appContext = new ClassPathXmlApplicationContext("com/gp6/aop/aspectJ/annotation/applicationContext.xml");
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
customer.addCustomer();
//customer.addCustomerReturnValue();
//customer.addCustomerThrowException();
//customer.addCustomerAround("gp6");
}
}
运行
logBefore() is running!================START
hijacked : addCustomer
logBefore() is running!================END
addCustomer() is running
4 . AspectJ @After
在下面例子中，logAfter()方法将在 customerBo 接口的 addCustomer()方法的执行之后执行。
File : LoggingAspect.java
package com.gp6.aop.aspectJ.annotation;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@After("execution(* com.gp6.aop.aspectJ.annotation.CustomerBo.addCustomer(..))")
public void logAfter(JoinPoint joinPoint) {
System.out.println("logAfter() is running!================START");
System.out.println("hijacked : " + joinPoint.getSignature().getName());
System.out.println("logAfter() is running!================END");
}
}
运行
addCustomer() is running
logAfter() is running!================START
hijacked : addCustomer
logAfter() is running!================END
5 . AspectJ @AfterReturning
在下面例子中，logAfterReturning()方法将在 customerBo 接口的addCustomerReturnValue()方法执行之后执行。此外，还可以截取返回的值使用“returning”属性。
要截取返回的值，对“returning”属性(结果)的值必须用相同的方法参数(结果)。
File : LoggingAspect.java
package com.gp6.aop.aspectJ.annotation;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@AfterReturning(pointcut = "execution(* com.gp6.aop.aspectJ.annotation.CustomerBo.addCustomerReturnValue(..))", returning= "result")
public void logAfterReturning(JoinPoint joinPoint, Object result) {
System.out.println("logAfterReturning() is running!================START");
System.out.println("hijacked : " + joinPoint.getSignature().getName());
System.out.println("Method returned value is : " + result);
System.out.println("logAfterReturning() is running!================END");
}
}
package com.gp6.aop.aspectJ.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) throws Exception {
ApplicationContext appContext = new ClassPathXmlApplicationContext("com/gp6/aop/aspectJ/annotation/applicationContext.xml");
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
//customer.addCustomer();
customer.addCustomerReturnValue();
//customer.addCustomerThrowException();
//customer.addCustomerAround("gp6");
}
}
运行
addCustomerReturnValue() is running
logAfterReturning() is running!================START
hijacked : addCustomerReturnValue
Method returned value is : abc
logAfterReturning() is running!================END
6. AspectJ @AfterThrowing
在下面的例子中，如果 customerBo 接口的addCustomerThrowException()方法抛出异常logAfterThrowing()方法将被执行。
File : LoggingAspect.java
package com.gp6.aop.aspectJ.annotation;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@AfterThrowing(pointcut = "execution(* com.gp6.aop.aspectJ.annotation.CustomerBo.addCustomerThrowException(..))",throwing= "error")
public void logAfterThrowing(JoinPoint joinPoint, Throwable error) {
System.out.println("logAfterThrowing() is running!================Start");
System.out.println("hijacked : " + joinPoint.getSignature().getName());
System.out.println("Exception : " + error);
System.out.println("logAfterThrowing() is running!================END");
}
}
package com.gp6.aop.aspectJ.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) throws Exception {
ApplicationContext appContext = new ClassPathXmlApplicationContext("com/gp6/aop/aspectJ/annotation/applicationContext.xml");
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
//customer.addCustomer();
//customer.addCustomerReturnValue();
customer.addCustomerThrowException();
//customer.addCustomerAround("gp6");
}
}
运行
addCustomerThrowException() is running
logAfterThrowing() is running!================Start
hijacked : addCustomerThrowException
Exception : java.lang.Exception: Generic Error
logAfterThrowing() is running!================END
Exception in thread "main" java.lang.Exception: Generic Error
at com.gp6.aop.aspectJ.annotation.CustomerBoImpl.addCustomerThrowException(CustomerBoImpl.java:15)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:318)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:55)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:90)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy5.addCustomerThrowException(Unknown Source)
at com.gp6.aop.aspectJ.annotation.Test.main(Test.java:16)
7 . AspectJ @Around
在下面例子中，logAround()方法将在customerBo接口的addCustomerAround()方法执行之前执行， 必须定义“joinPoint.proceed();” 控制何时拦截器返回控制到原来的addCustomerAround()方法。
File : LoggingAspect.java
package com.gp6.aop.aspectJ.annotation;
import java.util.Arrays;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
@Aspect
public class LoggingAspect {
@Around("execution(* com.gp6.aop.aspectJ.annotation.CustomerBo.addCustomerAround(..))")
public void logAround(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("logAround() is running!================START");
System.out.println("hijacked method : " + joinPoint.getSignature().getName());
System.out.println("hijacked arguments : " + Arrays.toString(joinPoint.getArgs()));
System.out.println("Around before is running!================START");
joinPoint.proceed(); //continue on the intercepted method
System.out.println("Around after is running!================START");
System.out.println("******");
}
}
package com.gp6.aop.aspectJ.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) throws Exception {
ApplicationContext appContext = new ClassPathXmlApplicationContext("com/gp6/aop/aspectJ/annotation/applicationContext.xml");
CustomerBo customer = (CustomerBo) appContext.getBean("customerBo");
//customer.addCustomer();
//customer.addCustomerReturnValue();
//customer.addCustomerThrowException();
customer.addCustomerAround("gp6");
}
}
运行
logAround() is running!================START
hijacked method : addCustomerAround
hijacked arguments : [gp6]
Around before is running!================START
addCustomerAround() is running, args : gp6
Around after is running!================START
******
总结
建议采用最少 AspectJ 注解。这是关于Spring AspectJ 的一篇相当长的文章。
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