restartGame() method returning errors

Question

My graded unit for college is to create a Crown & Anchor dice game in Java. Without having to go to much into the rules etc, here are some of the pointers that will be relevant..

Players enter their name on startup, my program should check source folder for playerName.ser to load their game state.
Players information on this file is their name, current stake and the bankers stakes (this information should be reloaded if the players saved file exists.
If it does not exist, player is advised on this, and asked what stake they want to play with and a new Player object is created.

I'll post the code that I have for the restartGame() but I've getting errors that I have been struggling with a couple weeks now. Feel like I'm banging my head against a wall.

Any help is appreciated.

public void restartGame() throws IOException
{
    //ask player for players name and save in playerName
    String playerName = ui.getName();

    System.out.println("Your name is : " + playerName); 

            File varTmpDir = new File("saves/" + playerName.toLowerCase() + ".ser");
            boolean exists = varTmpDir.exists();

            if(exists == true)
            {
               Player tempPlayer = null;

    try    
            {
                FileInputStream fileIn = new FileInputStream(playerName + ".ser");
                ObjectInputStream in = new ObjectInputStream(fileIn);
                tempPlayer = (Player) in.readObject();
                in.close();
                fileIn.close();
                String restartYN = "";
                    while(restartYN.equals("") || (restartYN.toUpperCase().charAt(0) != 'Y' && restartYN.toUpperCase().charAt(0) != 'N'))
            {
                System.out.println("Match found with £"+ tempPlayer.getStake() +" stake and £" + tempPlayer.getBanker() +" banker do you want to continue Y/N? ");
                restartYN = input.next();
            }
            if(restartYN.toUpperCase().charAt(0) == 'Y'){
                aPlayer = new Player(playerName,tempPlayer.getStake(),tempPlayer.getBanker());
            }   
             }catch(IOException i){
            System.out.println("Save corrupt starting new game. \n");
             }catch(ClassNotFoundException c) {
            System.out.println("Save corrupt starting new game. \n");
             }
            }

            int pStake = 0;
    do{
        System.out.print("No save loaded starting new game enter stake : £");
            String input2 = input.next();**//THIS IS THE ERROR LINE
        try {
            pStake = Integer.parseInt(input2);
            if(pStake <1){
                System.out.println("ERROR: must be a number above 0 with no decimal points less than 2147483648.");
            } 
        } catch (NumberFormatException ex){
            System.out.println("ERROR: must be a number above 0 with no decimal points less than 2147483648.");
        }
    }while(pStake<1);

    aPlayer = new Player(playerName,pStake,100);      
    }

After running the console application, I am asked the players name, but then the following errors occur..

run: Please enter your name and press ENTER chris Your name is : chris Exception in thread "main" java.lang.NullPointerException at cadice.Game.restartGame(Game.java:96) at cadice.Game.play(Game.java:30) at cadice.CrownAndAnchor.main(CrownAndAnchor.java:14) No save loaded starting new game enter stake : £C:\Users\chris\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53: Java returned: 1 BUILD FAILED (total time: 7 seconds)

This line 96 code refers to the line of code in I have commented beside in the restartGame() code:

String input2 = input.next();

Pretty new to this guys bear with me...this is my variables declared at start of Game class..

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Scanner;

    public class Game 
    {
    private CADice[] dice;
    private Player aPlayer;
    private ArrayList<Bet> bets;
    public UserInterface ui = new UserInterface();
    public char option;
    public Scanner input;

This error means that the variable `input` is null. Can we see where do you instantiate this variable ? — Titouan56, Feb 14 '17 at 14:13
Your spot on mate I'm not at all...the first playerName variable is set using User Interface class's method..Ill give this a bash. — newCoder1888, Feb 14 '17 at 14:25

score 0 · Accepted Answer · answered Feb 14 '17 at 14:22

0

You're not instanciating input anywhere. You need something like

input = new Scanner(System.in)

answered Feb 14 '17 at 14:22

Steve Smith

2,244
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This fixed the problem guys...2 weeks I've been stuck on this. Absolutely over the moon thanks. – newCoder1888 Feb 14 '17 at 14:28
We've all been there. :) `NullPointerException` is probably the most common error you'll ever get in Java. – Steve Smith Feb 14 '17 at 14:35
@newCoder1888 Don't forget to accept the answer. :) – Steve Smith Feb 14 '17 at 14:39
Sorry mate, just seen that there...is that the green tick aye? – newCoder1888 Feb 14 '17 at 14:47
Yep, that's the one. Cheers! – Steve Smith Feb 14 '17 at 14:54

restartGame() method returning errors

1 Answers1