Java IO Tutorial - Java DataOutputStream

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DataOutputStream can write Java primitive data type values to an output stream.

The DataOutputStream class contains a write method to write a data type. It supports writing a string to an output stream using the writeUTF(String text) method.

To write Java primitive data type values to a file named primitives.dat, we construct an object of DataOutputStream as follows:

DataOutputStream dos = new DataOutputStream(new FileOutputStream("primitives.dat"));

Example

The following code writes an int value, a double value, a boolean value, and a string to a file named primitives.dat.

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
/*www.java2s.com*/
public class Main {
 public static void main(String[] args) {
 String destFile = "primitives.dat";
 try (DataOutputStream dos = new DataOutputStream(new FileOutputStream(
 destFile))) {
 dos.writeInt(765);
 dos.writeDouble(6789.50);
 dos.writeBoolean(true);
 dos.writeUTF("Java Input/Output is cool!");
 dos.flush();
 System.out.println("Data has been written to "
 + (new File(destFile)).getAbsolutePath());
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
}

The code above generates the following result.

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