SERVLET.SOP

Minimize use of System.out.println or System.err

Description

This rule flags code that uses System.out.println or System.err.

Because System.out.prinln statements and similar constructs synchronize processing for the duration of disk I/O, they can significantly slow throughput.

Example

 package SERVLET;
 
 import javax.servlet.*;
 import javax.servlet.http.*;
 
 public class SOP extends HttpServlet {
     public void service () {
         System.out.println ("starting service");
     }
 }

Repair

 public class SOP extends HttpServlet {
     private final static boolean DEBUG_ON = false;
     public void service () {
         // activate tracing only when absolutely needed.
         if (DEBUG_ON) {
             System.out.println ("starting service");
         }
     }
 }

Reference

IBM WebSphere Application Server Standard and Advanced Editions, Harvey W. Gunther.

http://www-4.ibm.com/software/webservers/appserv/ws_bestpractices.pdf