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Thread: Java Password Saver Problem

  1. #1
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    Default Java Password Saver Problem

    Help
    Last edited by chesspro13; January 18th, 2013 at 06:31 PM. Reason: did not format


  2. #2
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    Exclamation Java Password Saver Problem

    I am working on a simple password saver that makes a text file and then i can add a website username and password, but whenever i try to add new information it says

    [COLOR="#FF0000"]Exception in thread "main" java.lang.NullPointerException
    at password.createFile.addRecords(createFile.java:32)
    at password.apple.main(apple.java:21)[COLOR]

    Can anyone help me understand why it does not work?

    here is the code
    --------------------------------------------------------------------------------------------
    package password;
    import java.util.*;
     
    public class apple {
    	public static void main(String[] args){
     
    		@SuppressWarnings("resource")
    		Scanner input = new Scanner(System.in);
    		System.out.print("what would you like to do? 'add' or 'see'?");
    		String option = input.nextLine();
     
    		if(option.equals("see")){
    			readFile r = new readFile(); 
    			r.openFile();
    			r.readFile();
    			r.closeFile();
    		}
    		if(option.equals("add")){
    			createFile g = new createFile();
    			//g.openFile();
    			g.addRecords();
    			g.closeFile();
    		}
    	}
    }
    --------------------------------------------------------------------------------------------
    package password;
    import java.io.File;
    import java.io.File.*;
    import java.util.*;
     
    public class createFile {
     
    	public static String web;
    	public static String user;
    	public static String pass;
    	private Formatter y;
    	public Scanner x;
     
    	public void openFile(){
    	try{
    		x = new Scanner(new File("test.txt"));
    		System.out.println("You crested a file");
    	}
    	catch(Exception e){
    		System.out.println("you have an error");
    	}
    	}
    	public void addRecords(){
    		@SuppressWarnings("resource")
    		Scanner input = new Scanner(System.in);
    		System.out.print("Website: ");
    		String web1 = input.nextLine();
    		System.out.print("Username: ");
    		String user = input.nextLine();
    		System.out.print("Password: ");
    		String pass = input.nextLine();
    		y.format("%s %s %s", web1, user, pass);
    	}
     
    		public void closeFile(){
    			x.close();
    		}
     
    }
    --------------------------------------------------------------------------------------------
    package password;
    import java.io.*;
    import java.util.*;
     
    public class readFile {
     
    	public Scanner z;
    	public static int one = 1;
     
    	public void openFile(){
    		try{
    			z = new Scanner(new File("test.txt"));
    		}
    		catch(Exception e){
    			System.out.println("Could not find file");
    		}
    	}
     
    	public void readFile() {
    		if(one == 1){
    			String a = z.next(); 
    			String b = z.next();
    			String c = z.next();
     
    			System.out.printf("%s %s %s", a, b, c);
     
    		}
    	}
    		public void closeFile(){
    			z.close();
    		}	
    }

  3. #3
    Super Moderator Norm's Avatar
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    Default Re: Java Password Saver Problem

    Exception in thread "main" java.lang.NullPointerException
    at password.createFile.addRecords(createFile.java:32)
    Look at line 32 in the your source and see what variable is null. Then backtrack in the code to see why that variable does not have a valid value.
    If you can not tell which variable it is, add a println just before line 32 and print out the values of all the variables on that line.

    Please edit your post and wrap your code with
    [code=java]
    <YOUR CODE HERE>
    [/code]
    to get highlighting and preserve formatting.
    If you don't understand my answer, don't ignore it, ask a question.

  4. #4
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    Default Re: Java Password Saver Problem

    I added the println and they all print, but it is still saying there is an error.

    this is what prints:

    what would you like to do? 'add' or 'see'?add
    Website: www.facebook.com
    Username: chesspro13
    Password: password
    www.facebook.com chesspro13 password
    Exception in thread "main" java.lang.NullPointerException
    at password.createFile.addRecords(createFile.java:30)
    at password.apple.main(apple.java:21)

  5. #5
    Super Moderator Norm's Avatar
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    Default Re: Java Password Saver Problem

    it is still saying there is an error.
    Printing out values won't fix the problem. It will tell you what is causing the problem so you can fix it.

    Exception in thread "main" java.lang.NullPointerException
    at password.createFile.addRecords(createFile.java:30)
    Look at line 30 and find the variable with the null value.
    If you don't understand my answer, don't ignore it, ask a question.

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