title: setting value inside property file at run time
body: <p>is it possible to set the value inside property file at runtime.</p>
  
  <p>I tried this and it changes while reading property back, but when I check in file that changes are not reflected.</p>
  
  <pre><code>       try {
              Properties props = new Properties();
              props.setProperty("ServerAddress", "ee");
              props.setProperty("ServerPort", "123");
              props.setProperty("ThreadCount", "456");
              File f = new File("myApp.properties");
  
              OutputStream out = new FileOutputStream( f );
              props.store(out, "This is an optional header comment string");
  
              System.out.println(props.get("ServerPort"));
              out.close();
         }
          catch (Exception e ) {
              e.printStackTrace();
          }
  </code></pre>
  
  <p>output:
  123.</p>
  
  <p>my need is to have one property file application wide and through GUI web page that configuration can be change. </p>