Open In App

DataInputStream readInt() method in Java with Examples

Improve
Improve
Like Article
Like
Save
Share
Report

The readInt() method of DataInputStream class in Java is used to read four input bytes and returns a integer value. This method reads the next four bytes from the input stream and interprets it into integer type and returns.

Syntax:

public final int readInt()
             throws IOException

Specified By: This method is specified by readInt() method of DataInput interface.

Parameters: This method does not accept any parameter.

Return value: This method returns the int value interpreted by the next four bytes of the input stream.

Exceptions:

  • EOFException – It throws EOFException if the input stream is ended before four bytes can be read.
  • IOException – This method throws IOException if the stream is closed or some other I/O error occurs.

Below programs illustrate readInt() method in DataInputStream class in IO package:

Program 1: Assume the existence of file “demo.txt”.




// Java program to illustrate
// DataInputStream readInt() method
import java.io.*;
public class GFG {
    public static void main(String[] args)
        throws IOException
    {
  
        // Create integer array
        int[] buf = { 10, 20, 30, 40, 50 };
  
        // Create file output stream
        FileOutputStream outputStream
            = new FileOutputStream("c:\\demo.txt");
  
        // Create data output stream
        DataOutputStream dataOutputStr
            = new DataOutputStream(outputStream);
  
        for (int b : buf) {
            // Write integer value to
            // the dataOutputStream
            dataOutputStr.writeInt(b);
        }
  
        dataOutputStr.flush();
  
        // Create file input stream
        FileInputStream inputStream
            = new FileInputStream("c:\\demo.txt");
  
        // Create data input stream
        DataInputStream dataInputStr
            = new DataInputStream(inputStream);
  
        while (dataInputStr.available() > 0) {
            // Print integer values
            System.out.println(
                dataInputStr.readInt());
        }
    }
}


Output:

Program 2: Assume the existence of file “demo.txt”.




// Java program to illustrate
// DataInputStream readInt() method
import java.io.*;
public class GFG {
    public static void main(String[] args)
        throws IOException
    {
  
        // Create integer array
        int[] buf = { 191, 225, 480, 763, 500 };
  
        // Create file output stream
        FileOutputStream outputStream
            = new FileOutputStream("c:\\demo.txt");
  
        // Create data output stream
        DataOutputStream dataOutputStr
            = new DataOutputStream(outputStream);
  
        for (int b : buf) {
            // Write integer value to
            // the dataOutputStream
            dataOutputStr.writeInt(b);
        }
  
        dataOutputStr.flush();
  
        // Create file input stream
        FileInputStream inputStream
            = new FileInputStream("c:\\demo.txt");
  
        // Create data input stream
        DataInputStream dataInputStr
            = new DataInputStream(inputStream);
  
        while (dataInputStr.available() > 0) {
            // Print integer values
            System.out.println(
                dataInputStr.readInt());
        }
    }
}


Output:

References:
https://docs.oracle.com/javase/10/docs/api/java/io/DataInputStream.html#readInt()



Last Updated : 05 Jun, 2020
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads