logging lifecyle events of servlet

[naveen yadav]

hi ranchers ,

i am new to Servlet . and i just exploring the basic things.As a part of this i want to create a small servlet program in which i log all the life cycle events of a servlet .

One idea is to just create a file using java.io api and write the event into that file .But i don't want to use that since there must be some standard way like tool aor api to do that.

please guide

[honey sachdeva]

hi,

you can use System.out.println().

this will write in web server log file .

[naveen yadav]

log(String message) in GenericServlet class :: Writes the specified message to a servlet log file, usually an event log. The name and type of the servlet log file is specific to the servlet container

but The name and type of the servlet log file is specific to the servlet container. how can i do that ?

[Bear Bibeault]

honey sachdeva wrote:you can use System.out.println().

Not the best of ideas.

Most professionals would use Common Logging with one of java.util.logging or Log4J.

[honey sachdeva]

yes you are write about java.util.logging or Log4J.

i just answer System.out.println() because he says " i am new to Servlet "

[naveen yadav]

i am currently using the GlassFish server. will Log4j work with GlassFish Server ?

[Kumaravadivel Subramani]

It's a common logging tool, work well with GlassFish.

[naveen yadav]

i am using Log4j with GlassFish Server.

i am trying to log the message that "servlet context is initialized." when the servlet of LifeCycle application is invoked

code goes as :

package org;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Logger;



public class MyServletContextListener implements ServletContextListener {

	@Override
	public void contextDestroyed(ServletContextEvent evt) {
	
	}

	
	@Override
	public void contextInitialized(ServletContextEvent evt) {
		

		Logger logger = Logger.getLogger(MyServletContextListener.class);
		BasicConfigurator.configure();
		logger.info("ServletContext is Initialized");

	}

}

i have added the required log4j-1.2.16 file to build path of application.

GlaasFish server cannot deploy the application(LifeCycle) and show following message :

cannot Deploy LifeCycle
Deployment Error for module: LifeCycle: Error occurred during deployment: Exception while loading the app : java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: java.lang.NoClassDefFoundError: org/apache/log4j/Logger.


help me out.

[Rob Spoor]

You must also add that JAR file to your web application's class path.

[Vic Hood]

Also, I would suggest you use something like SLF4J, since you say you are a beginner.

[naveen yadav]

thanks Rob.

i place the log4j-1.2.16.jar file inside WEB-INF\lib\ directory and it work fine.


one more thing it is related to Log4j :

BasicConfigurator. configure() method will log all the messages on the console. so according to this "ServletContext is Initialized" must be on console.

But the message is written into server log file and then server log file is displayed on console. how so ?

[naveen yadav]

hi ranchers ,

i created a small application in which i track all the life cycle events of LifeServlet servlet. And use the MyLogger class to log the event using the Log4j tool.

everything is working fine .But when is see the log file of server i get this :



[#|2011-12-08T11:23:06.078-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=10;_ThreadName=Thread-2;|0 [main] INFO org.MyLogger - ServletContext object is Initialized
|#]

[#|2011-12-08T11:23:06.093-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=10;_ThreadName=Thread-2;|WEB0671: Loading application [LifeCycle] at [/LifeCycle]|#]

[#|2011-12-08T11:23:06.093-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.core.com.sun.enterprise.v3.server|_ThreadID=10;_ThreadName=Thread-2;|CORE10010: Loading application LifeCycle done in 453 ms|#]

[#|2011-12-08T11:23:06.093-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.core.com.sun.enterprise.v3.server|_ThreadID=10;_ThreadName=Thread-2;|Oracle GlassFish Server 3.1.1 (12) startup time : Felix (1,219ms), startup services(3,093ms), total(4,312ms)|#]

[#|2011-12-08T11:23:06.125-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.tools.admin.com.sun.enterprise.container.common|_ThreadID=16;_ThreadName=Thread-2;|User [admin] from host localhost does not have administration access|#]

[#|2011-12-08T11:23:06.265-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.tools.admin.org.glassfish.server|_ThreadID=17;_ThreadName=Thread-2;|JMXStartupService: Started JMXConnector, JMXService URL = service:jmx:rmi://sunmicro-fe959d:8686/jndi/rmi://sunmicro-fe959d:8686/jmxrmi|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - intit() is called
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - intit() is called
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - service() is called
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - service() is called
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - ServletRequest object is Initialized
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - ServletRequest object is Initialized
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - ServletResponse object is Initialized
|#]

[#|2011-12-08T11:23:07.765-0800|INFO|oracle-glassfish3.1.1|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=18;_ThreadName=Thread-2;|1687 [http-thread-pool-8080(2)] INFO org.MyLogger - ServletResponse object is Initialized
|#]



I have two question

Q1 : why ServletContext is initialized before LifeCycle application is loaded ? shouln't be other ways around ?


Q2: why init() and service() is called twice?




for more understating here is my code of LifeServlet

package org;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.GenericServlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;



public class LifeServlet extends GenericServlet {
	
	private ServletConfig config = null;
	private ServletContext context = null;

	//MyLogger class uses the Log4j tool to log the various events of Lifecylce of servlet
	private MyLogger ob = null;
	
	
    public LifeServlet() {
        super();

      
    }

    public void init()throws ServletException{
    	  ob = new MyLogger();
  
    	ob.message("intit() is called");
    	
    	if(config!=null)
    		ob.message("ServletConfig object is Initialized");
    	
    	    	
    	
    	
    }
	public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
			
		ob.message("service() is called");
		if(request!=null)
    		ob.message("ServletRequest object is Initialized");
		if(response!=null)
    		ob.message("ServletResponse object is Initialized");
				
		
		response.setContentType("text/html");
		PrintWriter pw = response.getWriter();
		pw.println("<html><body>");
		pw.println("see server log file at "+ "C:\\glassfish3\\glassfish\\domains\\domain1\\logs");
		pw.println("<br></body></html>");
	
				
	}

}