Rename a File Using Java

How to rename a file without making another file (Java)

The File class doesn't represent the physic file in the hard drive, it is just an abstract representation. Creating a new instance of File class doesn't mean you are creating a physical file.

By knowing this, you can rename your file using a new File without worrying about creating new physical files. Code adapted from Rename a file using Java:

public static void renameFile(File toBeRenamed, String new_name)
throws IOException {
//need to be in the same path
File fileWithNewName = new File(toBeRenamed.getParent(), new_name);
if (fileWithNewName.exists()) {
throw new IOException("file exists");
}
// Rename file (or directory)
boolean success = toBeRenamed.renameTo(fileWithNewName);
if (!success) {
// File was not successfully renamed
}
}

EDIT: Based on your question update and on this comment:

I took a pic of the error. "Unhandled Exception Type IO Exception"

Looks one of these:

  1. You don't know how to handle checked exceptions.

    To do this, you should wrap the method that throws the Exception (or subclass) in a try-catch statement:

    String new_name = getFilename(file);
    try {
    renameFiles(files[i], new_name);
    } catch (IOException e) {
    //handle the exception
    //using a basic approach
    e.printStacktrace();
    }

    More info: Java Tutorial. Lesson: Exceptions.

  2. You don't want your method to throw a checked exception. In this case, it would be better to throw an unchecked exception instead, so you don't need to handle the exception manually. This can be done by throwing a new instance of RuntimeException or a subclass of this:

    public static void renameFile(File toBeRenamed, String new_name) {
    File fileWithNewName = new File(new_name);
    if (fileWithNewName.exists()) {
    throw new RuntimeException("file exists.");
    }
    // Rename file (or directory)
    boolean success = toBeRenamed.renameTo(fileWithNewName);
    if (!success) {
    // File was not successfully renamed
    }
    }

    More info in the link posted in the above section.

  3. You don't want to throw an exception at all. In this case, it would be better to at least return a value to know if the file was exactly renamed:

    public static boolean renameFile(File toBeRenamed, String new_name) {
    //need to be in the same path
    File fileWithNewName = new File(toBeRenamed.getParent(), new_name);
    if (fileWithNewName.exists()) {
    return false;
    }
    // Rename file (or directory)
    return toBeRenamed.renameTo(fileWithNewName);
    }

    And update your code accordingly:

    String new_name = getFilename(file);
    boolean result = renameFiles(files[i], new_name);
    if (!result) {
    //the file couldn't be renamed
    //notify user about this
    System.out.println("File " + files[i].getName() + " couldn't be updated.");
    }

Which one to choose? Will depend entirely on your taste. If I were you, I would use the third option for a quick dirty or learning phase work, but for a real world application I would use second option but using my own custom exception that extends from RuntimeException.

How to rename an existing file?

Try doing:

new File("loc/xyz1.mp3").renameTo(new File("loc/xyz.mp3"));

This should automatically overwrite the original file. This answer was taken from here: How to rename an existing file

How to rename file java ?

As @Pshemo pointed out you might be moving the file to the current directory. Try doing this instead. This will tell it to create the file under the given parent directory:

filesArray[i].renameTo(new File(thisFolder, "test" + i + ".pdf"));//thisFolder is your parent directory


Related Topics



Leave a reply



Submit