Java Cookbook

Deleting a File

Problem

You need to delete one or more files from disk.

Solution

Use a java.io.File object’s delete( ) method; it will delete files (subject to permissions) and directories (subject to permissions and to the directory being empty).

Discussion

This is not very complicated. Simply construct a File object for the file you wish to delete, and call its delete( ) method:

import java.io.*;

/**
 * Delete a file from within Java
 */
public class Delete {
    public static void main(String[] argv) throws IOException {

        // Construct a File object for the backup created by editing
        // this source file. The file probably already exists.
        // My editor creates backups by putting ~ at the end of the name.
        File bkup = new File("Delete.java~");
        // Quick, now, delete it immediately:
        bkup.delete(  );
    }
}

Just recall the caveat about permissions in the Introduction to this chapter: if you don’t have permission, you can get a return value of false or, possibly, a SecurityException. Note also that there are some differences between platforms. Windows 95 allows Java to remove a file that has the read-only bit, but Unix does not allow you to remove a file that you don’t have permission on or to remove a directory that isn’t empty. Here is a version of Delete with error checking (and reporting of success, too):

import java.io.*; /** * Delete a file from within Java, with error handling. */ public class Delete2 { public static void main(String argv[]) { for (int i=0; i<argv.length; i++) delete(argv[i]); ...