CODEWITHSUNDEEP
java
Rumen Hristov
Rumen Hristov

Reputation: 887

ArrayIndexOutOfBoundsException: 1. What is wrong with my indexing? Java

Essentially, wrote a program that reads off values from the following .txt file

P1 0 8
P2 1 4
P3 2 9
P4 3 3
p8 4 5

each line represents a process with its attributes. p1 is a name, 0 is arr_time of p1 and 8 is burst_time of p1 as per the following class:

public class Process {

    private String name;
    private int arrive_time= 0;
    private int burst_time = 0;
    private int remain_time = 0;

    public Process (String name, int arr_time, int bur_time) {

        this.arrive_time = arr_time;
        this.burst_time = bur_time;
        this.remain_time = burst_time;
        this.name = name;
    }

    public int getArrTime() {return arrive_time;}
    public int getBurTime() {return burst_time;}
    public int getRemTime() {return remain_time;}
    public String getName() {return name;}

    public void decRemTime() {this.remain_time--;}
}

I have the following code which is supposed to read and parse the .txt file. Every time it sees a new line it has to add a new process to the priorityQueue prq. It parses and successfully stores the lines of the .txt, but throws a java.lang.ArrayIndexOutOfBoundsException: 1. And I tried tracing it and debugging for hours unsuccessfully. I don't know where it is passing a non-existent index... Here's the problematic code. The error-producing section is in the while loop and I have described it there in a comment.

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;

public class Test {

    //Priority READY_QUEUE for the accessed processes
    public static PriorityQueue<Process> prq = new PriorityQueue<Process>(5, new Comparator<Process> () {

        @Override
        public int compare(Process p1, Process p2) {
            return p1.getArrTime() - p2.getArrTime();
        }
    });

    public static void main(String[] args) throws IOException {

        BufferedReader br = null;
        String line;

        try {
            br =  new BufferedReader(new FileReader("C:\\Users\\Veni\\Desktop\\test\\test.txt\\"));
        }
        catch (FileNotFoundException fnfex) {
            System.out.println(fnfex.getMessage() + "File not found");
            System.exit(0);
        }

        /*
         * We get an error here in the ParseInt operation
         * immediately following the first while loop iteration
         */ 
        while((line = br.readLine()) != null) {

            System.out.println("reentering while loop");

            String[] params = line.split(" ");

            System.out.println(params[0]);
            System.out.println(Integer.parseInt(params[1]));
            System.out.println(Integer.parseInt(params[2]));
            System.out.println("done");

            prq.add(new Process(params[0], Integer.parseInt(params[1]), Integer.parseInt(params[2]) ));
        }
    }
}

I am pretty sure (from my tracing) that the problem arises after the first iteration through the while loop. The problem is at the ParseInt operation. And I am completely stuck and confused about it.

Upvotes: 1

Views: 97

Answers (3)

Sumit Singh
Sumit Singh

Reputation: 15886

Before using array index check the size of array like:

String[] params = line.split(" ");
if(params.length < 3){
  // your code if length is not as expected
}

Answer for comment: Before spiting you should add following condition to check if line if empty:

if("".equals(line.trim())){
  continue;
}

Upvotes: 5

nisarg109
nisarg109

Reputation: 204

I have checked your code and it runs successfully and gives output. And when I put some white space at starting it is giving me ArrayIndexOutOfBoundsException : 1 error. So, this might be a space problem. I got this output:

reentering while loop
P1
0
8
done
reentering while loop
P2
1
4
done
reentering while loop
P3
2
9
done
reentering while loop
P4
3
3
done
reentering while loop
p8
4
5
done

Upvotes: 2

Pumphouse
Pumphouse

Reputation: 2053

Wondering if a non-visible /n is throwing you off.

Maybe put a if(params.length > 3) check before you index into it.

If you had a /n you couldn't see, that may cause your array to be smaller.

Upvotes: 1

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