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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; @Component 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; 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 @Component public 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