Hello Friends, The below code will show you how you can read System Environments Variables and System Properties by Using Spring applicationContext.

We have to create SystemVariables Class and create the property systemVariables

SystemVariables.java

package com.manish;

public class SystemVariables {

    private String systemVariables;

    public String getSystemVariables() {
        return systemVariables;
    }

    public void setSystemVariables(String systemVariables) {
        this.systemVariables = systemVariables;
    }



}

In below appContext.xml we can insert the values of System Variables and Environment Variables.

appContext.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: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/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">


    <context:property-placeholder location="classpath*:prop.properties" />

   <context:annotation-config/>

       <bean id="systemVar" class="com.manish.SystemVariables">
           <property name="systemVariables" value="#{systemEnvironment['HOME']}" />

       </bean>

       <bean id="systemVar1" class="com.manish.SystemVariables">
           <property name="systemVariables" value="#{systemProperties['os.name']}" />

       </bean>
       <bean id="systemVar2" class="com.manish.SystemVariables">
           <property name="systemVariables" value="#{systemProperties['user.dir']}" />
       </bean>
</beans>

Finally We have print the values of System Variables in App.java.

App.java

package com.app;

import java.util.Properties;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.manish.Course;
import com.manish.Student;
import com.manish.SystemVariables;
import com.sun.org.apache.bcel.internal.generic.GETSTATIC;

public class App {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        AbstractApplicationContext ctx=new ClassPathXmlApplicationContext(new String[]{"app-context.xml"});


        SystemVariables sysVar=(SystemVariables)ctx.getBean("systemVar");
        SystemVariables sysVar1=(SystemVariables)ctx.getBean("systemVar1");
        SystemVariables sysVar2=(SystemVariables)ctx.getBean("systemVar2");

        System.out.println("System Enviornment  : "+sysVar.getSystemVariables());
        System.out.println("Operating System : "+sysVar1.getSystemVariables());
        System.out.println("User Directory : "+sysVar2.getSystemVariables());




    }

}