Pointcut with args()

There can be errors difficult to catch if you do not define the pointcut precisely specially with the args(name)

we are using args() to catch the JoinPoint with argumets.

Eg: we write a Pontcut to catch setter for Circle.java

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package org.aop.service;

import org.aop.model.Circle;
import org.aop.model.Triangle;

public class ShapeService {

 private Circle circle;
 private Triangle triangle;

 public Circle getCircle() {
  return circle;
 }

 public void setCircle(Circle circle) {
  this.circle = circle;
 }

 public Triangle getTriangle() {
  return triangle;
 }

 public void setTriangle(Triangle triangle) {
  this.triangle = triangle;
 }

}

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package org.aop.model;

public class Circle {

 private String name;

 public String getName() {
  return name;
 }

 public void setName(String name) {
  this.name = name;
 }

}

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public class AppMain {
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext(
"spring.xml");

// you need to cast if not use second parameter ShapeService.class
ShapeService shapeService = ctx.getBean("shapeService",
ShapeService.class);


shapeService.getCircle().setName("dummy name");
}

}

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package org.aop.aspect;

import org.aop.model.Circle;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;

@Aspect
public class LoginAspect {



@Before("argumentMethods(name)")
public void secondAdvice(String name) {
System.out.println("Second advice executed."+ name);
}



@Pointcut("args(name)")
public void argumentMethods(String name) {
}

}

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As shown above we have pointcut argumentMethods

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@Pointcut("args(name)")
public void argumentMethods(String name) {
}
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it is used in the advice = secondAdvice

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 @Before("argumentMethods(name)")
 public void secondAdvice(String name) {
 System.out.println("Second advice executed."+ name);
 }
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If any case we forget include parameter "name", there will be exception.It's exception in initializing the beans. Because of this simple thing, all initialization fails.

eg: we remove the name parameter from advice method
Note : parameter  missing name in the secondAdvice
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 @Before("argumentMethods(name)")
public void secondAdvice() {
System.out.println("Second advice executed.");
}
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exception will be
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Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'triangle' defined in class path resource [spring.xml]: Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: warning no match for this type name: name [Xlint:invalidAbsoluteTypeName]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:529)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:296)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:293)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.(ClassPathXmlApplicationContext.java:83)
at org.aop.main.AppMain.main(AppMain.java:9)
Caused by: java.lang.IllegalArgumentException: warning no match for this type name: name [Xlint:invalidAbsoluteTypeName]
at org.aspectj.weaver.tools.PointcutParser.parsePointcutExpression(PointcutParser.java:301)
at org.springframework.aop.aspectj.AspectJExpressionPointcut.buildPointcutExpression(AspectJExpressionPointcut.java:209)
at org.springframework.aop.aspectj.AspectJExpressionPointcut.buildPointcutExpression(AspectJExpressionPointcut.java:196)
at org.springframework.aop.aspectj.AspectJExpressionPointcut.checkReadyToMatch(AspectJExpressionPointcut.java:185)
at org.springframework.aop.aspectj.AspectJExpressionPointcut.getClassFilter(AspectJExpressionPointcut.java:166)
at org.springframework.aop.support.AopUtils.canApply(AopUtils.java:208)
at org.springframework.aop.support.AopUtils.canApply(AopUtils.java:262)
at org.springframework.aop.support.AopUtils.findAdvisorsThatCanApply(AopUtils.java:294)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findAdvisorsThatCanApply(AbstractAdvisorAutoProxyCreator.java:118)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findEligibleAdvisors(AbstractAdvisorAutoProxyCreator.java:88)
at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.getAdvicesAndAdvisorsForBean(AbstractAdvisorAutoProxyCreator.java:69)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:359)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:322)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:409)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1518)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521)
... 11 more