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03-spring-aop

readme.md

AOP with Spring and AspectJ

Let's play and learn more about Spring AOP

  • Step 01 - Setting up AOP Example - Part 1
  • Step 02 - Setting up AOP Example - Part 2
  • Step 03 - Defining an @Before advice
  • Step 04 - Understand AOP Terminology - Pointcut, Advice, Aspect, Join Point, Weaving and Weaver
  • Step 05 - Using @After, @AfterReturning, @AfterThrowing advices
  • Step 06 - Using @Around advice to implement performance tracing
  • Step 07 - Best Practice : Use common Pointcut Configuration
  • Step 08 - Quick summary of other Pointcuts
  • Step 09 - Creating Custom Annotation and an Aspect for Tracking Time

Complete Code Example

Complete Code Example

/pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.in28minutes.spring.aop</groupId>
	<artifactId>spring-aop</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>spring-aop</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

	<pluginRepositories>
		<pluginRepository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</pluginRepository>
		<pluginRepository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</pluginRepository>
	</pluginRepositories>


</project>

/src/main/java/com/in28minutes/spring/aop/springaop/aspect/AfterAopAspect.java

package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

//AOP
//Configuration
@Aspect
@Configuration
public class AfterAopAspect {

	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@AfterReturning(value = "com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.businessLayerExecution()", 
			returning = "result")
	public void afterReturning(JoinPoint joinPoint, Object result) {
		logger.info("{} returned with value {}", joinPoint, result);
	}
	
	@After(value = "com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.businessLayerExecution()")
	public void after(JoinPoint joinPoint) {
		logger.info("after execution of {}", joinPoint);
	}
}

/src/main/java/com/in28minutes/spring/aop/springaop/aspect/CommonJoinPointConfig.java

package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.annotation.Pointcut;

public class CommonJoinPointConfig {
	
	@Pointcut("execution(* com.in28minutes.spring.aop.springaop.data.*.*(..))")
	public void dataLayerExecution(){}
	
	@Pointcut("execution(* com.in28minutes.spring.aop.springaop.business.*.*(..))")
	public void businessLayerExecution(){}
	
	@Pointcut("dataLayerExecution() && businessLayerExecution()")
	public void allLayerExecution(){}
	
	@Pointcut("bean(*dao*)")
	public void beanContainingDao(){}
	
	@Pointcut("within(com.in28minutes.spring.aop.springaop.data..*)")
	public void dataLayerExecutionWithWithin(){}

	@Pointcut("@annotation(com.in28minutes.spring.aop.springaop.aspect.TrackTime)")
	public void trackTimeAnnotation(){}

}

/src/main/java/com/in28minutes/spring/aop/springaop/aspect/MethodExecutionCalculationAspect.java

package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

@Aspect
@Configuration
public class MethodExecutionCalculationAspect {

	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@Around("com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.trackTimeAnnotation()")
	public void around(ProceedingJoinPoint joinPoint) throws Throwable {
		long startTime = System.currentTimeMillis();

		joinPoint.proceed();

		long timeTaken = System.currentTimeMillis() - startTime;
		logger.info("Time Taken by {} is {}", joinPoint, timeTaken);
	}
}

/src/main/java/com/in28minutes/spring/aop/springaop/aspect/TrackTime.java

package com.in28minutes.spring.aop.springaop.aspect;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface TrackTime {

}

/src/main/java/com/in28minutes/spring/aop/springaop/aspect/UserAccessAspect.java

package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

//AOP
//Configuration
@Aspect
@Configuration
public class UserAccessAspect {
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());
	
	//What kind of method calls I would intercept
	//execution(* PACKAGE.*.*(..))
	//Weaving & Weaver
	@Before("com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.dataLayerExecution()")
	public void before(JoinPoint joinPoint){
		//Advice
		logger.info(" Check for user access ");
		logger.info(" Allowed execution for {}", joinPoint);
	}
}

/src/main/java/com/in28minutes/spring/aop/springaop/business/Business1.java

package com.in28minutes.spring.aop.springaop.business;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.in28minutes.spring.aop.springaop.aspect.TrackTime;
import com.in28minutes.spring.aop.springaop.data.Dao1;

@Service
public class Business1 {
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());
	
	@Autowired
	private Dao1 dao1;
	
	@TrackTime
	public String calculateSomething(){
		//Business Logic
		String value = dao1.retrieveSomething();
		logger.info("In Business - {}", value);
		return value;
	}
}

/src/main/java/com/in28minutes/spring/aop/springaop/business/Business2.java

package com.in28minutes.spring.aop.springaop.business;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.in28minutes.spring.aop.springaop.data.Dao2;

@Service
public class Business2 {
	
	@Autowired
	private Dao2 dao2;
	
	public String calculateSomething(){
		//Business Logic
		return dao2.retrieveSomething();
	}
}

/src/main/java/com/in28minutes/spring/aop/springaop/data/Dao1.java

package com.in28minutes.spring.aop.springaop.data;

import org.springframework.stereotype.Repository;

import com.in28minutes.spring.aop.springaop.aspect.TrackTime;

@Repository
public class Dao1 {
	
	@TrackTime
	public String retrieveSomething(){
		return "Dao1";
	}

}

/src/main/java/com/in28minutes/spring/aop/springaop/data/Dao2.java

package com.in28minutes.spring.aop.springaop.data;

import org.springframework.stereotype.Repository;

@Repository
public class Dao2 {

	public String retrieveSomething(){
		return "Dao2";
	}

}

/src/main/java/com/in28minutes/spring/aop/springaop/SpringAopApplication.java

package com.in28minutes.spring.aop.springaop;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.in28minutes.spring.aop.springaop.business.Business1;
import com.in28minutes.spring.aop.springaop.business.Business2;

@SpringBootApplication
public class SpringAopApplication implements CommandLineRunner{
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@Autowired
	private Business1 business1;

	@Autowired
	private Business2 business2;
	
	public static void main(String[] args) {
		SpringApplication.run(SpringAopApplication.class, args);
	}

	@Override
	public void run(String... args) throws Exception {
		logger.info(business1.calculateSomething());
		logger.info(business2.calculateSomething());
	}
}

/src/main/resources/application.properties


    
      
      
    
  




/src/test/java/com/in28minutes/spring/aop/springaop/SpringAopApplicationTests.java


package com.in28minutes.spring.aop.springaop;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringAopApplicationTests {

	@Test
	public void contextLoads() {
	}

}

    
      
      
    
  




Complete Code Example


/pom.xml


<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.in28minutes.spring.aop</groupId>
	<artifactId>spring-aop</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>spring-aop</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

	<pluginRepositories>
		<pluginRepository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</pluginRepository>
		<pluginRepository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</pluginRepository>
	</pluginRepositories>


</project>

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/aspect/AfterAopAspect.java


package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

//AOP
//Configuration
@Aspect
@Configuration
public class AfterAopAspect {

	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@AfterReturning(value = "com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.businessLayerExecution()", 
			returning = "result")
	public void afterReturning(JoinPoint joinPoint, Object result) {
		logger.info("{} returned with value {}", joinPoint, result);
	}
	
	@After(value = "com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.businessLayerExecution()")
	public void after(JoinPoint joinPoint) {
		logger.info("after execution of {}", joinPoint);
	}
}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/aspect/CommonJoinPointConfig.java


package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.annotation.Pointcut;

public class CommonJoinPointConfig {
	
	@Pointcut("execution(* com.in28minutes.spring.aop.springaop.data.*.*(..))")
	public void dataLayerExecution(){}
	
	@Pointcut("execution(* com.in28minutes.spring.aop.springaop.business.*.*(..))")
	public void businessLayerExecution(){}
	
	@Pointcut("dataLayerExecution() && businessLayerExecution()")
	public void allLayerExecution(){}
	
	@Pointcut("bean(*dao*)")
	public void beanContainingDao(){}
	
	@Pointcut("within(com.in28minutes.spring.aop.springaop.data..*)")
	public void dataLayerExecutionWithWithin(){}

	@Pointcut("@annotation(com.in28minutes.spring.aop.springaop.aspect.TrackTime)")
	public void trackTimeAnnotation(){}

}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/aspect/MethodExecutionCalculationAspect.java


package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

@Aspect
@Configuration
public class MethodExecutionCalculationAspect {

	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@Around("com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.trackTimeAnnotation()")
	public void around(ProceedingJoinPoint joinPoint) throws Throwable {
		long startTime = System.currentTimeMillis();

		joinPoint.proceed();

		long timeTaken = System.currentTimeMillis() - startTime;
		logger.info("Time Taken by {} is {}", joinPoint, timeTaken);
	}
}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/aspect/TrackTime.java


package com.in28minutes.spring.aop.springaop.aspect;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface TrackTime {

}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/aspect/UserAccessAspect.java


package com.in28minutes.spring.aop.springaop.aspect;

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;

//AOP
//Configuration
@Aspect
@Configuration
public class UserAccessAspect {
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());
	
	//What kind of method calls I would intercept
	//execution(* PACKAGE.*.*(..))
	//Weaving & Weaver
	@Before("com.in28minutes.spring.aop.springaop.aspect.CommonJoinPointConfig.dataLayerExecution()")
	public void before(JoinPoint joinPoint){
		//Advice
		logger.info(" Check for user access ");
		logger.info(" Allowed execution for {}", joinPoint);
	}
}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/business/Business1.java


package com.in28minutes.spring.aop.springaop.business;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.in28minutes.spring.aop.springaop.aspect.TrackTime;
import com.in28minutes.spring.aop.springaop.data.Dao1;

@Service
public class Business1 {
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());
	
	@Autowired
	private Dao1 dao1;
	
	@TrackTime
	public String calculateSomething(){
		//Business Logic
		String value = dao1.retrieveSomething();
		logger.info("In Business - {}", value);
		return value;
	}
}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/business/Business2.java


package com.in28minutes.spring.aop.springaop.business;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.in28minutes.spring.aop.springaop.data.Dao2;

@Service
public class Business2 {
	
	@Autowired
	private Dao2 dao2;
	
	public String calculateSomething(){
		//Business Logic
		return dao2.retrieveSomething();
	}
}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/data/Dao1.java


package com.in28minutes.spring.aop.springaop.data;

import org.springframework.stereotype.Repository;

import com.in28minutes.spring.aop.springaop.aspect.TrackTime;

@Repository
public class Dao1 {
	
	@TrackTime
	public String retrieveSomething(){
		return "Dao1";
	}

}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/data/Dao2.java


package com.in28minutes.spring.aop.springaop.data;

import org.springframework.stereotype.Repository;

@Repository
public class Dao2 {

	public String retrieveSomething(){
		return "Dao2";
	}

}

    
      
      
    
  




/src/main/java/com/in28minutes/spring/aop/springaop/SpringAopApplication.java


package com.in28minutes.spring.aop.springaop;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.in28minutes.spring.aop.springaop.business.Business1;
import com.in28minutes.spring.aop.springaop.business.Business2;

@SpringBootApplication
public class SpringAopApplication implements CommandLineRunner{
	
	private Logger logger = LoggerFactory.getLogger(this.getClass());

	@Autowired
	private Business1 business1;

	@Autowired
	private Business2 business2;
	
	public static void main(String[] args) {
		SpringApplication.run(SpringAopApplication.class, args);
	}

	@Override
	public void run(String... args) throws Exception {
		logger.info(business1.calculateSomething());
		logger.info(business2.calculateSomething());
	}
}

    
      
      
    
  




/src/main/resources/application.properties



    
      
      
    
  




/src/test/java/com/in28minutes/spring/aop/springaop/SpringAopApplicationTests.java


package com.in28minutes.spring.aop.springaop;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringAopApplicationTests {

	@Test
	public void contextLoads() {
	}

}