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基于注解的AOP 方式
1.加入jar包
com.springsource.org.aopalliance-1.0.0.jar
com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar
commons-logging-1.1.3.jar
spring-aop-4.1.0.RELEASE.jar
spring-aspects-4.1.0.RELEASE.jar
spring-beans-4.1.0.RELEASE.jar
spring-context-4.1.0.RELEASE.jar
spring-core-4.1.0.RELEASE.jar
spring-expression-4.1.0.RELEASE.jar
2.在配置文件中加入AOP的命名空间
3.基于注解的方式
①在配置文件中加入如下配置
<aop:aspectj-autoproxy></aop:aspectj-autoproxy>
②把横切关注点的代码抽象到切面的类中
切面首先是一个IOC中的bean,即加入@Component注解
切面还需要加入@Aspect注解
③在类中声明各种通知
@Before 前置通知,在方法执行之前执行
@After 后置通知,在方法执行之后执行
@AfterRunning 返回通知,在方法返回结果之后执行
@AfterThrowing 异常通知,在方法抛出异常之后执行
@Around 环绕通知,围绕着方法执行
③在方法中声明一个类型为JoinPoint的参数就可以访问链接细节
ArithmeticCalculator接口
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package com.spring.aop.impl;public interface ArithmeticCalculator { public int add(int i, int j); public int sub(int i, int j); public int mul(int i, int j); public int div(int i, int j);} |
接口实现类 ArithmeticCalculatorImpl.java
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package com.spring.aop.impl;import org.springframework.stereotype.Component;@Componentpublic class ArithmeticCalculatorImpl implements ArithmeticCalculator{ @Override public int add(int i, int j) { int result = i + j; return result; } @Override public int sub(int i, int j) { int result = i - j; return result; } @Override public int mul(int i, int j) { int result = i * j; return result; } @Override public int div(int i, int j) { int result = i / j; return result; }} |
切面类 LoggingAspect.java
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package com.spring.aop.impl;import java.util.ArrayList;import java.util.Arrays;import java.util.List;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;import org.springframework.core.annotation.Order;import org.springframework.stereotype.Component;//指定切面的优先级,当有多个切面时,数值越小优先级越高@Order(1)//把这个类声明为一个切面:需要把该类放入到IOC容器中。再声明为一个切面.@Aspect@Componentpublic class LoggingAspect { /** * 声明切入点表达式,一般在该方法中不再添加其他代码。 * 使用@Pointcut来声明切入点表达式。 * 后面的通知直接使用方法名来引用当前的切入点表达式。 */ @Pointcut("execution(public int com.spring.aop.impl.ArithmeticCalculator.*(..))") public void declareJoinPointExpression() {} /** *前置通知,在目标方法开始之前执行。 *@Before("execution(public int com.spring.aop.impl.ArithmeticCalculator.add(int, int))")这样写可以指定特定的方法。 * @param joinpoint */ @Before("declareJoinPointExpression()") //这里使用切入点表达式即可。后面的可以都改成切入点表达式。如果这个切入点表达式在别的包中,在前面加上包名和类名即可。 public void beforeMethod(JoinPoint joinpoint) { String methodName = joinpoint.getSignature().getName(); List<Object>args = Arrays.asList(joinpoint.getArgs()); System.out.println("前置通知:The method "+ methodName +" begins with " + args); } /** *后置通知,在目标方法执行之后开始执行,无论目标方法是否抛出异常。 *在后置通知中不能访问目标方法执行的结果。 * @param joinpoint */ @After("execution(public int com.spring.aop.impl.ArithmeticCalculator.*(int, int))") public void afterMethod(JoinPoint joinpoint) { String methodName = joinpoint.getSignature().getName(); //List<Object>args = Arrays.asList(joinpoint.getArgs()); 后置通知方法中可以获取到参数 System.out.println("后置通知:The method "+ methodName +" ends "); } /** *返回通知,在方法正常结束之后执行。 *可以访问到方法的返回值。 * @param joinpoint * @param result 目标方法的返回值 */ @AfterReturning(value="execution(public int com.spring.aop.impl.ArithmeticCalculator.*(..))", returning="result") public void afterReturnning(JoinPoint joinpoint, Object result) { String methodName = joinpoint.getSignature().getName(); System.out.println("返回通知:The method "+ methodName +" ends with " + result); } /** *异常通知。目标方法出现异常的时候执行,可以访问到异常对象,可以指定在出现特定异常时才执行。 *假如把参数写成NullPointerException则只在出现空指针异常的时候执行。 * @param joinpoint * @param e */ @AfterThrowing(value="execution(public int com.spring.aop.impl.ArithmeticCalculator.*(..))", throwing="e") public void afterThrowing(JoinPoint joinpoint, Exception e) { String methodName = joinpoint.getSignature().getName(); System.out.println("异常通知:The method "+ methodName +" occurs exception " + e); } /** * 环绕通知类似于动态代理的全过程,ProceedingJoinPoint类型的参数可以决定是否执行目标方法。 * @param point 环绕通知需要携带ProceedingJoinPoint类型的参数。 * @return 目标方法的返回值。必须有返回值。 */ /*不常用 @Around("execution(public int com.spring.aop.impl.ArithmeticCalculator.*(..))") public Object aroundMethod(ProceedingJoinPoint point) { Object result = null; String methodName = point.getSignature().getName(); try { //前置通知 System.out.println("The method "+ methodName +" begins with " + Arrays.asList(point.getArgs())); //执行目标方法 result = point.proceed(); //翻译通知 System.out.println("The method "+ methodName +" ends with " + result); } catch (Throwable e) { //异常通知 System.out.println("The method "+ methodName +" occurs exception " + e); throw new RuntimeException(e); } //后置通知 System.out.println("The method "+ methodName +" ends"); return result; } */} |
applicationContext.xml
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<?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-4.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd"> <!-- 配置自动扫描包 --> <context:component-scan base-package="com.spring.aop.impl"></context:component-scan> <!-- 使AspectJ注解起作用:自动为匹配的类生产代理对象 --> <aop:aspectj-autoproxy></aop:aspectj-autoproxy></beans> |
Main.java
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package com.spring.aop.impl;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Main {public static void main(String[] args) { //创建spring IOC容器 ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml"); //从IOC容器中获取bean实例 ArithmeticCalculator arithmeticCalculator = applicationContext.getBean(ArithmeticCalculator.class); int result = arithmeticCalculator.add(4, 6); System.out.println(result); result = arithmeticCalculator.sub(4, 6); System.out.println(result); System.out.println(result); result = arithmeticCalculator.mul(4, 6); System.out.println(result); System.out.println(result); result = arithmeticCalculator.div(4, 0); System.out.println(result);}} |
基于配置文件的AOP 方式
引入的jar包与基于注解的方式引入的jar包相同
ArithmeticCalculator接口
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package com.spring.aop.impl.xml;public interface ArithmeticCalculator { public int add(int i, int j); public int sub(int i, int j); public int mul(int i, int j); public int div(int i, int j);} |
接口实现类 ArithmeticCalculatorImpl.java
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package com.spring.aop.impl.xml;public class ArithmeticCalculatorImpl implements ArithmeticCalculator{ @Override public int add(int i, int j) { int result = i + j; return result; } @Override public int sub(int i, int j) { int result = i - j; return result; } @Override public int mul(int i, int j) { int result = i * j; return result; } @Override public int div(int i, int j) { int result = i / j; return result; }} |
切面类 LoggingAspect.java
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package com.spring.aop.impl.xml;import java.util.Arrays;import java.util.List;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.ProceedingJoinPoint;public class LoggingAspect { public void beforeMethod(JoinPoint joinpoint) { String methodName = joinpoint.getSignature().getName(); List<Object>args = Arrays.asList(joinpoint.getArgs()); System.out.println("前置通知:The method "+ methodName +" begins with " + args); } public void afterMethod(JoinPoint joinpoint) { String methodName = joinpoint.getSignature().getName(); //List<Object>args = Arrays.asList(joinpoint.getArgs()); 后置通知方法中可以获取到参数 System.out.println("后置通知:The method "+ methodName +" ends "); } public void afterReturnning(JoinPoint joinpoint, Object result) { String methodName = joinpoint.getSignature().getName(); System.out.println("返回通知:The method "+ methodName +" ends with " + result); } public void afterThrowing(JoinPoint joinpoint, Exception e) { String methodName = joinpoint.getSignature().getName(); System.out.println("异常通知:The method "+ methodName +" occurs exception " + e); } public Object aroundMethod(ProceedingJoinPoint point) { Object result = null; String methodName = point.getSignature().getName(); try { //前置通知 System.out.println("The method "+ methodName +" begins with " + Arrays.asList(point.getArgs())); //执行目标方法 result = point.proceed(); //翻译通知 System.out.println("The method "+ methodName +" ends with " + result); } catch (Throwable e) { //异常通知 System.out.println("The method "+ methodName +" occurs exception " + e); throw new RuntimeException(e); } //后置通知 System.out.println("The method "+ methodName +" ends"); return result; }} |
切面类 ValidationAspect.java
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package com.spring.aop.impl.xml;import java.util.Arrays;import org.aspectj.lang.JoinPoint;public class ValidationAspect { public void validateArgs(JoinPoint joinPoint) { System.out.println("validate:" + Arrays.asList(joinPoint.getArgs())); }} |
applicationContext-xml.xml
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<?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" 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-4.1.xsd"> <!-- 配置bean --> <bean id="arithmeticCalculator" class="com.spring.aop.impl.xml.ArithmeticCalculatorImpl"></bean> <!-- 配置切面的bean --> <bean id="loggingAspect" class="com.spring.aop.impl.xml.LoggingAspect"></bean> <bean id="validationAspect" class="com.spring.aop.impl.xml.ValidationAspect"></bean> <!-- 配置AOP --> <aop:config> <!-- 配置切点表达式 --> <aop:pointcut expression="execution(* com.spring.aop.impl.xml.ArithmeticCalculator.*(..))" id="pointcut"/> <!-- 配置切面及通知,使用order指定优先级 --> <aop:aspect ref="loggingAspect" order="1"> <!-- 环绕通知 --> <!-- <aop:around method="aroundMethod" pointcut-ref="pointcut"/> --> <!-- 前置通知 --> <aop:before method="beforeMethod" pointcut-ref="pointcut"/> <!-- 后置通知 --> <aop:after method="afterMethod" pointcut-ref="pointcut"/> <!-- 异常通知 --> <aop:after-throwing method="afterThrowing" pointcut-ref="pointcut" throwing="e"/> <!-- 返回通知 --> <aop:after-returning method="afterReturnning" pointcut-ref="pointcut" returning="result"/> </aop:aspect> <aop:aspect ref="validationAspect" order="2"> <!-- 前置通知 --> <aop:before method="validateArgs" pointcut-ref="pointcut"/> </aop:aspect> </aop:config></beans> |
Main.java
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package com.spring.aop.impl.xml;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class Main {public static void main(String[] args) { //创建spring IOC容器 ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext-xml.xml"); //从IOC容器中获取bean实例 ArithmeticCalculator arithmeticCalculator = applicationContext.getBean(ArithmeticCalculator.class); int result = arithmeticCalculator.add(4, 6); System.out.println(result); result = arithmeticCalculator.sub(4, 6); System.out.println(result); System.out.println(result); result = arithmeticCalculator.mul(4, 6); System.out.println(result); System.out.println(result); result = arithmeticCalculator.div(4, 0); System.out.println(result);}}
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原文地址:http://www.cnblogs.com/yudar/p/4601563.html