How to log the error/variables info in java classes

Question

We are using the third party jar and the jar is independent to the application. So this is why I am not able to see any errors in the web server log. In that file using the below sample code is using. And my problem is I am not able to print the variables info either in web page or in the terminal. Please can any one suggest how to make it possible(to print the variables info).Just fyi, the methods in this class are calling by Java bean and the java bean in turn calling by servlet.
============================
import SPSecurity.configuration.SecurityConfiguration;
import SPSecurity.exception.NoDataFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.*;
import javax.servlet.http.*;
public class BasicUserInformation
public BasicUserInformation()
//intialization
public void initialize(String s, int i)
//some code with variables
public void initialize(HttpServletRequest httpservletrequest)
// some code with variables
private void setUserIdandTypeProperties()
     //Some code with variable.
}

Answer 1

The answer is reflection
Read the following tutorial
[http://java.sun.com/docs/books/tutorial/reflect/index.html]