JAVA EE: Spring Bean Life Cycle - ApplicationContextAware Interface

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Spring Bean Life Cycle - ApplicationContextAware Interface | Spring Tutorial

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%20http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.ram.core</groupId>

    <artifactId>SpringDemo</artifactId>

    <packaging>jar</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>SpringDemo</name>

    <url>http://maven.apache.org</url>

    <properties>

        <spring.version>5.0.2.RELEASE</spring.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>3.8.1</version>

            <scope>test</scope>

        </dependency>

        <!-- Spring 5 dependencies -->

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-core</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-context</artifactId>

            <version>${spring.version}</version>

        </dependency>

    </dependencies>

</project>

Employee.java

package com.ram.model;

/**

 * Spring bean

 */

public class Employee

{

    private String name;

    public void setName(String name)

    {

        this.name = name;

    }

    @Override

    public String toString()

    {

        return "Employee [name=" + name + "]";

    }

}

ApplicationContextAwareImpl.java

package com.ram.contextaware;

import org.springframework.beans.BeansException;

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;

import com.ram.model.Employee;

public class ApplicationContextAwareImpl implements ApplicationContextAware

{

    private ApplicationContext applicationContext;

    public void setApplicationContext(ApplicationContext applicationContext)

            throws BeansException

    {

        System.out.println(

                "setApplicationContext method called by the Spring Container");

        this.applicationContext = applicationContext;

    }

    public void displayEmployeeDetails()

    {

        Employee employee = applicationContext.getBean("employee",

                Employee.class);

        System.out.println(

                "Got employee object from the ApplicationContext(Spring Container) = "

                        + employee);

        System.out.println("is employee object Singleton? = "

                + applicationContext.isSingleton("employee"));

    }

}

applicationContext.xml

<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-4.3.xsd">

    <bean id="employee" class="com.ram.model.Employee">

        <property name="name" value="Peter" />

    </bean>

    <bean id="applicationContextAware" class="com.ram.contextaware.ApplicationContextAwareImpl" />

</beans>

App.java

package com.ram.core;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.ram.contextaware.ApplicationContextAwareImpl;

public class App

{

    public static void main(String[] args)

    {

        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext(

                "applicationContext.xml");

        ApplicationContextAwareImpl applicationContextAwareImpl = applicationContext

                .getBean("applicationContextAware",

                        ApplicationContextAwareImpl.class);

        applicationContextAwareImpl.displayEmployeeDetails();

        applicationContext.close();

    }

}

Output

Aug 11, 2018 11:11:22 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh

INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@5b37e0d2: startup date [Sat Aug 11 11:11:22 IST 2018]; root of context hierarchy

Aug 11, 2018 11:11:23 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions

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

setApplicationContext method called by the Spring Container

Got employee object from the ApplicationContext(Spring Container) = Employee [name=Peter]

is employee object Singleton? = true

Aug 11, 2018 11:11:23 AM org.springframework.context.support.AbstractApplicationContext doClose

INFO: Closing org.springframework.context.support.ClassPathXmlApplicationContext@5b37e0d2: startup date [Sat Aug 11 11:11:22 IST 2018]; root of context hierarchy