Java FileOutputStream Create File if not exists

Question

It will throw a FileNotFoundException if the file doesn't exist and cannot be created (doc), but it will create it if it can. To be sure you probably should first test that the file exists before you create the FileOutputStream (and create with createNewFile() if it doesn't):

File yourFile = new File("score.txt");
yourFile.createNewFile(); // if file already exists will do nothing 
FileOutputStream oFile = new FileOutputStream(yourFile, false); 

Before creating a file, it's necessary to create all parent directories.

Use yourFile.getParentFile().mkdirs()

Update: Create all parent folders only when they are not exist. Otherwise it is not necessary.

FileUtils from apache commons is a pretty good way to achieve this in a single line.

FileOutputStream s = FileUtils.openOutputStream(new File("/home/nikhil/somedir/file.txt"))

This will create parent folders if do not exist and create a file if not exists and throw a exception if file object is a directory or cannot be written to. This is equivalent to:

File file = new File("/home/nikhil/somedir/file.txt");
file.getParentFile().mkdirs(); // Will create parent directories if not exists
file.createNewFile();
FileOutputStream s = new FileOutputStream(file,false);

All the above operations will throw an exception if the current user is not permitted to do the operation.

You can create an empty file whether it exists or not ...

new FileOutputStream("score.txt", false).close();

if you want to leave the file if it exists ...

new FileOutputStream("score.txt", true).close();

You will only get a FileNotFoundException if you try to create the file in a directory which doesn't exist.

File f = new File("Test.txt");
if(!f.exists()){
  f.createNewFile();
}else{
  System.out.println("File already exists");
}

Pass this f to your FileOutputStream constructor.

Create file if not exist. If file exits, clear its content:

/**
 * Create file if not exist.
 *
 * @param path For example: "D:\foo.xml"
 */
public static void createFile(String path) {
    try {
        File file = new File(path);
        if (!file.exists()) {
            file.createNewFile();
        } else {
            FileOutputStream writer = new FileOutputStream(path);
            writer.write(("").getBytes());
            writer.close();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}