FileOutputStream : FileOutputStream « File « Java Tutorial

  1. The FileOutputStream class is a subclass of OutputStream.
  2. You can construct a FileOutputStream object by passing a string containing a path name or a File object.
  3. You can also specify whether you want to append the output to an existing file.
public FileOutputStream (String path)
public FileOutputStream (String path, boolean append)
public FileOutputStream (File file)
public FileOutputStream (File file, boolean append)

With the first and third constructors, if a file by the specified name already exists, the file will be overwritten. To append to an existing file, pass true to the second or fourth constructor.


public class MainClass {
  public static void main(String[] args) {
    File originFile = new File("c:\\file1.txt");
    File destinationFile = new File("c:\\file1.txt");
    if (!originFile.exists() || destinationFile.exists()) {
    try {
      byte[] readData = new byte[1024];
      FileInputStream fis = new FileInputStream(originFile);
      FileOutputStream fos = new FileOutputStream(destinationFile);
      int i =;

      while (i != -1) {
        fos.write(readData, 0, i);
        i =;
    } catch (IOException e) {

11.14.2.Create a file output stream directly from the file name
11.14.3.Create DataOutputStream from FileOutputStream
11.14.4.Create FileOutputStream object from File object
11.14.5.Create FileOutputStream object from String file path
11.14.6.Use FileOutputStream to read integers
11.14.7.Use FileOutputStream to write the bytes to a file.
11.14.8.Get FileChannel from FileOutputStream
11.14.9.File IO
11.14.10.Write file using FileOutputStream
11.14.11.Write byte array to a file using FileOutputStream
11.14.12.Write double to a file using DataOutputStream
11.14.13.Append output to file using FileOutputStream
11.14.14.Write UTF String, integer and double with DataOutputStream
11.14.15.Copy a file with FileInputStream and FileOutputStream
11.14.16.Forcing Updates to a File to the Disk
11.14.17.serializes an object to an output stream.