code: public boolean saveJMXSettings() {
          Log log = config.getLog();
          
          // create and validate file
          File settingsFile = getSettingsFile();
          
          // create the jmx properties state
          Properties properties  = new Properties();
          
          saveSetting(properties, "EdenSpace", edenSpace);
          saveSetting(properties, "SurvivorSpace", survivorSpace);
          saveSetting(properties, "PermGen", permGen);
          saveSetting(properties, "TenuredGen", tenuredGen);
          
          saveSetting(properties, "YoungCollector", youngCollector);
          saveSetting(properties, "TenuredCollector", tenuredCollector);
          
          // save the properties
          String comment = "Saved JMX settings on " + new Date();
          FileOutputStream out = null;
          
          try {
              out = new FileOutputStream(settingsFile);
              properties.store(out, comment);
          }
          catch (IOException ioe) {
              log.error("Unable to save JMX settings: " + ioe.getMessage());
              log.error(ioe);
              return false;
          }
          finally {
              try { if (out != null) { out.close(); } }
              catch (IOException e) { /* ignore */ }
          }
          
          // success
          return true;
      }
docs: Save the configured JMX settings for memory pools and collectors so that
  the customized settings will be persisted across restarts.  The settings
  are stored in the temporary/working directory of the servlet.
  
  @return true if successfully saved, false otherwise