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