Spring AOP's pointcut expression using @within() AspectJ Designator with Example

Open Eclipse
Click on menu New -> Others
In wizards type "Java Project" and Select "Java Project"
Click Next
Enter project name as "AOPLogBeforeAndAfterMethodUsingwithinAnnotaion", then click Next
Goto Libraries tab, then click on Add External JARs, then select Spring's 21 Framework Jars aopalliance-1.0.jar, aspectjtools-1.6.6.jar and commons-logging-1.1.jar.
Click Finish.

Step.2 Project Explorer Preview

StudentAdditionalDetails.java

package com.springexample;
 
@StudentQualifier
public class StudentAdditionalDetails extends Student {
    private String age;
    private String city;
    private String state;
     
    public String getAge() {
        return age;
    }
    public void setAge(String age) {
        this.age = age;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getState() {
        return state;
    }
    public void setState(String state) {
        this.state = state;
    }   
     
    public void display(){
        System.out.println("Age: "+age);
        System.out.println("City: "+city);
        System.out.println("State: "+state);
    }
}

RunMyProgram.java

package com.springexample;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class RunMyProgram {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        {
            StudentAdditionalDetails student = (StudentAdditionalDetails) context.getBean("studentAdditionalDetails");
            student.display();
        }
    }
}

beans.xml

<?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-3.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
    <bean id="student" class="com.springexample.Student">
        <property name="studentNo" value="1001" />
        <property name="studentName" value="John Peter" />
    </bean>
     
    <bean id="studentAdditionalDetails" class="com.springexample.StudentAdditionalDetails">
        <property name="age" value="29" />
        <property name="city" value="New york" />
        <property name="state" value="American State" />
    </bean>
     
    <bean id="mylogger" class="com.springexample.MyLogger" />
     
    <aop:config>
        <aop:aspect ref="mylogger">
            <aop:pointcut expression="@within(com.springexample.StudentQualifier)" id="studentDisplayLogsPnt"/>
             
            <aop:before pointcut-ref="studentDisplayLogsPnt" method="beforeDisplay" />
            <aop:after pointcut-ref="studentDisplayLogsPnt" method="afterDisplay" />
        </aop:aspect>
    </aop:config>
 
</beans>

StudentQualifier.java

package com.springexample;
 
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
 
@Target({ElementType.TYPE,ElementType.PARAMETER,ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface StudentQualifier {
}

MyLogger.java

package com.springexample;
 
public class MyLogger {
    public void beforeDisplay(){
        System.out.println("Before display!");
    }
    public void afterDisplay(){
        System.out.println("After display!");
    }
}

Student.java

package com.springexample;
 
public class Student {
    private int studentNo;
    private String studentName;
     
    public int getStudentNo() {
        return studentNo;
    }
    public void setStudentNo(int studentNo) {
        this.studentNo = studentNo;
    }
    public String getStudentName() {
        return studentName;
    }
    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }   
     
    public void display(){
        System.out.println("No: "+studentNo);
        System.out.println("Name: "+studentName);
    }
}