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() methodimport 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()); } }} |
Program 2: Assume the existence of file “demo.txt”.
// Java program to illustrate// DataInputStream readInt() methodimport 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()); } }} |
References:
https://docs.oracle.com/javase/10/docs/api/java/io/DataInputStream.html#readInt()
