NULLPointer Exception

[phyzix5761]

I have a Null Pointer exception in the following code but I can't figure out why. The variable "line" has been initialized and returns a value before and after the exception.

import java.util.*;
import java.io.*;

public class chatBot
{
	static Scanner sc = new Scanner(System.in);
	static String uInput = "";
		
	public static void main(String[] args)
	{
		while(true)
			{
				System.out.println("Input text");
				uInput = sc.nextLine();
				uInput = uInput.toUpperCase();
				removePunctuation();
				System.out.println(response(uInput));				
			}		
	}
	
	static String response = "";
	
	public static String response(String uInput)
	{
			try
			{
				response = findPattern("data/" +uInput.substring(0,1) + ".txt");
			}
			catch(IOException e)
			{
				response = "I don't know what you're talking about.";
			}
		
		return response;
		
	}
	
	public static String findPattern(String filename) throws IOException
	{
		FileReader fileReader = new FileReader(filename);
		
		BufferedReader bufferedReader = new BufferedReader(fileReader);
		String line = "";
		String line2 = "";
		
		while((line = bufferedReader.readLine()) != null)
		{
			if(line.startsWith("<pattern>"))
			{ 
				int i = line.indexOf(">");
				line = line.substring(i+1);
				Random rand = new Random();
				
				List<String> responses = new ArrayList<String>();
				String[] responseHolder = {};
				
				if(uInput.equals(line))
				{
					line = bufferedReader.readLine();
					while(line.startsWith("<response>"))
					{
						i = line.indexOf(">");
						responses.add(line.substring(i+1));
						line = bufferedReader.readLine();
					}
					
					responseHolder = responses.toArray(new String
							[responses.size()]);
					line = "Rogue: "+ responseHolder[rand.nextInt
					                    (responseHolder.length)];
					break;
				
				}
			}
		}
		
		bufferedReader.close();
		
		FileReader fileReader2 = new FileReader(filename);
		BufferedReader bufferedReader2 = new BufferedReader(fileReader2);
		String star1 = "";
		
		if(line == "NULL" || line == null)
		{//open file a second time to search for * option
			while((line = bufferedReader2.readLine()) != null)
			{
				
				if(line.startsWith("<pattern>"))
				{
					int i = line.indexOf(">");
					if(line.contains("*"))
					{
						int j = line.indexOf("*");
						String divLine1 = line.substring(i+1,j);
						
						if(uInput.length() >= divLine1.length())
						{
							star1 = uInput.substring(divLine1.length());
						}
						else
							star1 = "";
						
						if(line.substring(j+1)!=null)
						{
							String divLine2 = line.substring(j+1);
							
							if(divLine2=="" || divLine2 == null)
							{
								line = divLine1.substring(i+1,j);
							}
							else
								line = divLine1;
								line2 = divLine2;
							
							List<String> responses = new ArrayList<String>();
							String[] responseHolder = {};
							Random rand = new Random();
							
							if(uInput.startsWith(line) && (uInput.contains(line2) 
									|| (divLine2 == "" || divLine2 == null)))
							{
								
								line = bufferedReader2.readLine();
								try
								{
								while(line.startsWith("<response>"))
								{
										i = line.indexOf(">");
										responses.add(line.substring(i+1));
										line = bufferedReader2.readLine();
								}
								}
								catch(NullPointerException e)
								{
									e.printStackTrace();
								}
								
								responseHolder = responses.toArray(new String
										[responses.size()]);
								
								for(int a = 0; a<responseHolder.length; a++)
								{
									if(responseHolder[a].contains("<star1>"))
									{
										responseHolder[a] =
												responseHolder[a].replace
												("<star1>", star1.toLowerCase());
									}
									
								}
								line = "Rogue: "+ responseHolder[rand.nextInt
								                    (responseHolder.length)];
								break;
							}
							else
							{
								line = "I don't know what you're talking about.";
								break;
							}
							
						}
					}
				}

			}
			
		}
		bufferedReader2.close();
		return line;
	}

	public static void removePunctuation()
	{
		uInput = uInput.replaceAll("\\?", "");
		uInput = uInput.replaceAll("\\.", "");
		uInput = uInput.replaceAll("\\!", "");
		uInput = uInput.replaceAll("\\'", "");
		uInput = uInput.replaceAll("\\,", "");
	}

}

This is the stack trace print out:

java.lang.NullPointerException
at chatBot.findPattern(chatBot.java:126)
at chatBot.response(chatBot.java:27)
at chatBot.main(chatBot.java:17)

[Fubarable]

What line causes the exception? This information is always critically important and *always* should be included in questions like these. Else we are forced to guess which isn't fair.

[phyzix5761]

I apologize I meant to put line 126.

[Fubarable]

We know it's this line number based on the exception text, but again, which line is line 126?

[phyzix5761]

while(line.startsWith("<response>"))

[Fubarable]

Now we can answer the question, thank you. You'll want to read the bufferedReader API to see what it returns when it reaches the end of input, and this will tell you why you're having your current problem.

[phyzix5761]

According to some documentation I read bufferedReader returns null at the end of a file. I've tried to add a while((line = bufferedReader2.readLine()) != null) wrapping the error line and it still gives me the error. Not sure what is wrong.

[Fubarable]

If you've made a significant change, please show the new code. Please show the new code's error message, and again indicate which line throws the exception.