CODEWITHSUNDEEP
java
ravelinx
ravelinx

Reputation: 1795

Can't figured out the error of this RandomAccessFile code in Java

Im learning java and currently studying Streams (Byte and Character), I wrote this code that writes an array in an .txt and then read's and prints the value written before. When compiling I have and error in the line 22 that says 

method readInt in class RandomAccessFile cannot be applied to given types; 
d = rand.readInt(4*i);

required: no arguments 
foung: int
reason: actual and formal argument lists differ int length

heres the code: 

 import java.io.*;

        class Prueba7
        {
            public static void main(String args[])
            {
                int array[] = {2,5,3,6,4,7,4,8};
                int d;


                try(RandomAccessFile rand = new RandomAccessFile("prueba7.txt", "rw"))
                {
        for(int i: array)
                {
                    System.out.println("Writing: " +i);
                    rand.writeInt(i);
                }           

                for(int i = 0; i < array.length; i++)
                {

                    d = rand.readInt(4*i);
                    System.out.println("Reading file: ");
                    System.out.print(d);
                }
                }
                catch(IOException exc)
                {
                    System.out.println("Exception: " +exc);
                }
            }
        }

As I read the error, tried to delete the argument in readInt but I got an exception and not the output expected.

import java.io.*;

    class Prueba7
    {
        public static void main(String args[])
        {
            int array[] = {2,5,3,6,4,7,4,8};
            int d;


            try(RandomAccessFile rand = new RandomAccessFile("prueba7.txt", "rw"))
            {
    for(int i: array)
            {
                System.out.println("Writing: " +i);
                rand.writeInt(i);
            }           

            for(int i = 0; i < array.length; i++)
            {
                d = rand.readInt();
                System.out.println("Reading file: ");
                System.out.print(d);
            }
            }
            catch(IOException exc)
            {
                System.out.println("Exception: " +exc);
            }
        }
    }

with this I got this output:

writing: 2
writing: 5
writing: 3
writing: 6
writing: 4
writing: 7
writing: 4
writing: 8
Exception: java.io.EOFException

this is the output I want:

writing: 2
writing: 5
writing: 3
writing: 6
writing: 4
writing: 7
writing: 4
writing: 8
Reading: 2 5 3 6 4 7 4 8

Upvotes: 1

Views: 394

Answers (1)

dkatzel
dkatzel

Reputation: 31658

After you finish writing the file, you have to reset the file pointer back to the beginning.

..//write code for loop
rand.seek(0)

..//read code for loop

Upvotes: 2

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