NullPointerException at Java.util.StringTokenizer

[Ben Owats]

Hi Guys,

I am new to this forum seeking some help.

Here's the code :

import java.text.DateFormat;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Date;
import java.util.StringTokenizer;
import java.io.*;
import java.util.*;
import java.text.*;

public class final_exam{
public static void main(String args[])
{
	
	String Filename = "EmployeeDTR.txt";
	
	try 
	{
	
		FileReader fr = new FileReader(Filename);
		BufferedReader br = new BufferedReader(fr);
		
		String list = br.readLine();
		
		System.out.println("\n\t\t\tEmployer's Daily Time Record \n");
		date(list);
		
		while(list !=null)
		{
			list = br.readLine();
			EmployeeProfile(list);
		}
		
		fr.close();
	
	}

	catch(IOException e)
		{
			System.out.println("Problem Reading File: " + Filename);
		}

}

//---------------------get the date---------------------------------

public static void date(String list)
{
	StringTokenizer st = new StringTokenizer(list,"");	
	while(st.hasMoreTokens())
	
	{
		final String[] in = {"\t\t\t " + st.nextToken()+ " \n" };
			for ( final String s : in ) {
			System.out.println( s.replaceAll ( "\\*(\\b)","$1 " ) );
		}
			System.out.println("-----------------------------------------------------------------------------\n\n");
	}				

}

// -----------------get the employee profile-------------------------

public static void EmployeeProfile(String list)
{
	String EmployeeID,FirstName,LastName,position,rank,Am_In, Am_Out,Pm_In,Pm_Out;
	
	
	double rank1 = 26 * 380.00;
	double rank2 = 26 * 450.00;
	double rank3 = 26 * 550.00;	
	double tsalary =0;
	
	
	StringTokenizer st = new StringTokenizer(list,"*_");


	FirstName = st.nextToken();
	LastName = st.nextToken();
	EmployeeID = st.nextToken();
	position = st.nextToken();	
	rank = st.nextToken();	
	Am_In = st.nextToken(); //08:00
	Am_Out = st.nextToken();//12:00
	Pm_In = st.nextToken();
	Pm_Out = st.nextToken();
			
		
	if(rank.equals("1"))
	{
	    tsalary = rank1;
	} else if (rank.equals("2")){
		tsalary = rank2;
	}else if (rank.equals("3")){
		tsalary = rank3;
	}

	
	System.out.println("\n\tEmployee ID: " + EmployeeID);
	System.out.println("\tLast Name  : " + LastName);
	System.out.println("\tFirst Name : " + FirstName);
	System.out.println("\tPosition   : " + position);
	System.out.println("\tRank       : " + rank);
	
	NumberFormat df = new DecimalFormat("#,###.00");					
	System.out.println("\tRate       : Php " + df.format(tsalary));
	
			
	System.out.println("\n\tMorning");
	System.out.println("\t     IN    : " + Am_In);
	System.out.println("\t    OUT    : " + Am_Out);
	System.out.println("\n\tAfternoon");
	System.out.println("\t     IN    : " + Pm_In);
	System.out.println("\t    OUT    : " + Pm_Out);
	
	String tiami = Am_In;
    String tiamo = Am_Out;
    String tipmi = Pm_In;
    String tipmo = Pm_Out;

    // Custom date format
    SimpleDateFormat format = new SimpleDateFormat("HH:mm");  

    Date d1 = null;
    Date d2 = null;
    Date d3 = null;
    Date d4 = null;
    try {
            d1 = format.parse(tiami);
            d2 = format.parse(tiamo);
            d3 = format.parse(tipmi);
            d4 = format.parse(tipmo);
        } catch (ParseException e) {
            e.printStackTrace();
        }    
		
	long diff1 = d2.getTime() - d1.getTime();
	long diff2 = d4.getTime() - d3.getTime();
		 
    // Get msec from each, and subtract.
               
    long difft = diff1 + diff2 ;
    long diffMinutes = difft / (60 * 1000)% 60;         
    long diffHours = difft / (60 * 60 * 1000);                    
        
         
		
	System.out.println("\n\tTotal hours worked: " + diffHours + " hrs and " + diffMinutes + " mins \n");
	System.out.println("-----------------------------------------------------------------------------"); 

}


}

Here's the output:




This quite working. At the bottom of the output you can see the error occurred.

How can I fix it?


Any help very much appreciated.

Thanks,
Ben

[Stuart A. Burkett]

Print out the value of list after line 35 and see if it is always what you are expecting - take special note of the first and last time through the loop.

[Ben Owats]

Thanks Stuart for the reply...

Is this what you mean?

while(list !=null)  
        {  
            list = br.readLine();  
            System.out.println(list); // in this section?
            EmployeeProfile(list);  
        }  

If so, still the problem occurred. Their is a data from text file showing in the output. I don't if that's what you mean of "Print out the value of list after line 35". I'm not good in looping...

Here's the output :

[Matthew Brown]

Hi Ben. Welcome to the Ranch!

Think about the order you're doing things in that loop. You check if list is null, then you get the next token, then you create the employee profile. So when list is finally null...you still carry on. Your second version confirms this - you print out null. You need to stop as soon as that happens.

[Stuart A. Burkett]

Ben Owats wrote:If so, still the problem occurred.

That wasn't how to fix it. That was how to debug it. Look at the first result that you print out in the EmployeeProfile method. Is that the data from the first record in the input file or the second one ?

[Jo Joseph]

At line 33 you may try
while ((list = br.readLine()) != null) {
EmployeeProfile(list);
}

While we use br.readLine it will be reading the next line so the list will be null.

[Ben Owats]

Yes, Its working now....

Thank you very much Jo!

Thank you for the reply guys!

Cheer!