How to Access System Properties by using java programming ?

How to Access System Properties by using java programming ?

use java programming  language and set/get value of a system property

import java.util.Enumeration;

import java.util.Properties;

public class ListingAllSystemProperties {

  public static void main(String[] args) {

    //List All System Properties

    Properties props = System.getProperties();

    Enumeration enumeration = props.keys();

    while (enumeration.hasMoreElements()) {

      String propName = (String) enumeration.nextElement();

      String propValue = (String)props.get(propName);

      System.out.println(propName + " = " + propValue); 

    }

      

    // Set a system property

    String previousValue = System.setProperty("myjava.version", "5.0");

    //Get a system property

    String version = System.getProperty("myjava.version");

    System.out.println("myjava.version=" + version);  

      

  }

}

Here is an example to get the working directory (which is the location in the file system from where the java command was invoked):

    String curDir = System.getProperty("user.dir");

A system property can be set or overridden by specifying the -D option to the java command when running your program.

    java -Dmyjava.version="5.0" MyApplication