Java IO Tutorial - Java DataInputStream

DataInputStream can read Java primitive data type values from an input stream.

The DataInputStream class contains read methods to read a value of a data type. For example, to read an int value, it contains a readInt() method; to read a char value, it has a readChar() method, etc. It also supports reading strings using the readUTF() method.

Example

The following code shows how to read primitive values and Strings from a File.

import java.io.DataInputStream;
import java.io.FileInputStream;
//www.java2s.com
public class Main {
 public static void main(String[] args) {
 String srcFile = "primitives.dat";
 try (DataInputStream dis = new DataInputStream(new FileInputStream(srcFile))) {
 // Read the data in the same order they were written 
 int intValue = dis.readInt();
 double doubleValue = dis.readDouble();
 boolean booleanValue = dis.readBoolean();
 String msg = dis.readUTF();
 System.out.println(intValue);
 System.out.println(doubleValue);
 System.out.println(booleanValue);
 System.out.println(msg);
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
}

The code above generates the following result.