Spring Bean Life Cycle Example

pom.xml

<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>SpringBeanLifeCycle</groupId>
<artifactId>SpringBeanLifeCycle</artifactId>
<version>0.0.1-SNAPSHOT</version>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<java.version>1.8</java.version>
<spring-framework.version>4.3.8.RELEASE</spring-framework.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring-framework.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring-framework.version}</version>
</dependency>

</dependencies>
</project>

applicationContext.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"

xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="user" class="com.masterjee.User" />

<bean id="userService" class="com.masterjee.UserService">

<property name="user" ref="user" />

</bean>

<bean id="myService" class="com.masterjee.MyService" />

<bean

class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />

</beans>

User.java

package com.masterjee;

public class User {

    private int id;

    private String name;

    private String email;

    private String contact;

    private String password;

    private String passwordConfirm;

    public User(){

        System.out.println("Creating User instance");

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getEmail() {

        return email;

    }

    public void setEmail(String email) {

        this.email = email;

    }

    public String getPassword() {

        return password;

    }

    public void setPassword(String password) {

        this.password = password;

    }

    public String getContact() {

        return contact;

    }

    public void setContact(String contact) {

        this.contact = contact;

    }

    public String getPasswordConfirm() {

        return passwordConfirm;

    }

    public void setPasswordConfirm(String passwordConfirm) {

        this.passwordConfirm = passwordConfirm;

    }

}

UserService.java

package com.masterjee;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

public class UserService {

    private User user;

    @PostConstruct

    public void init() {

        System.out.println("init method of UserService using @PostConstruct");

        this.user.setName("Anil");

    }

    public UserService() {

        System.out.println("creating instance of UserService");

    }

    @PreDestroy

    public void destroy() {

        System.out.println("destroy method of UserService using @PreDestroy");

    }

    public User getUser() {

        return user;

    }

    public void setUser(User user) {

        this.user = user;

    }

}

MyService.java

package com.masterjee;

import javax.annotation.PostConstruct;

import javax.annotation.PreDestroy;

public class MyService {

    @PostConstruct

    public void init() {

        System.out.println("init method of UserService using @PostConstruct");

    }

    public MyService() {

        System.out.println("creating instance of UserService");

    }

    @PreDestroy

    public void destroy() {

        System.out.println("destroy method of UserService using @PreDestroy");

    }

}

MainClass.java

package com.masterjee;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainClass {

    public static void main(String[] args) {

        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        System.out.println("Spring Context started");

        UserService userService = (UserService) applicationContext.getBean("userService");

        System.out.println("Bean received from application context");

        System.out.println("name: "+userService.getUser().getName());

        applicationContext.close();

        System.out.println("Spring Context closed");

    }

}

Console

May 18, 2017 5:26:18 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh

INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@433c675d: startup date [Thu May 18 17:26:18 IST 2017]; root of context hierarchy

May 18, 2017 5:26:18 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions

INFO: Loading XML bean definitions from class path resource [applicationContext.xml]

Creating User instance

creating instance of UserService

init method of UserService using @PostConstruct

creating instance of UserService

init method of UserService using @PostConstruct

Spring Context started

Bean received from application context

name: Anil

May 18, 2017 5:26:19 PM org.springframework.context.support.ClassPathXmlApplicationContext doClose

INFO: Closing org.springframework.context.support.ClassPathXmlApplicationContext@433c675d: startup date [Thu May 18 17:26:18 IST 2017]; root of context hierarchy

destroy method of UserService using @PreDestroy

destroy method of UserService using @PreDestroy

Spring Context closed