/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.io;import java.io.*;/** * This class is a static method delete() and a standalone program that * deletes a specified file or directory. **/public class Delete {    /**      * This is the main() method of the standalone program.  After checking     * it arguments, it invokes the Delete.delete() method to do the deletion     **/    public static void main(String[] args) {        if (args.length != 1) {    // Check command-line arguments            System.err.println("Usage: java Delete <file or directory>");            System.exit(0);        }        // Call delete() and display any error messages it throws.        try { delete(args[0]); }        catch (IllegalArgumentException e) {	    System.err.println(e.getMessage());	}    }             /**     * The static method that does the deletion.  Invoked by main(), and     * designed for use by other programs as well.  It first makes sure that     * the specified file or directory is deleteable before attempting to     * delete it.  If there is a problem, it throws an     * IllegalArgumentException.     **/    public static void delete(String filename) {        // Create a File object to represent the filename        File f = new File(filename);        // Make sure the file or directory exists and isn't write protected        if (!f.exists()) fail("Delete: no such file or directory: " +filename);        if (!f.canWrite()) fail("Delete: write protected: " + filename);        // If it is a directory, make sure it is empty        if (f.isDirectory()) {            String[] files = f.list();            if (files.length > 0)		fail("Delete: directory not empty: " + filename);        }        // If we passed all the tests, then attempt to delete it        boolean success = f.delete();	        // And throw an exception if it didn't work for some (unknown) reason.        // For example, because of a bug with Java 1.1.1 on Linux,         // directory deletion always fails         if (!success) fail("Delete: deletion failed");    }    /** A convenience method to throw an exception */    protected static void fail(String msg) throws IllegalArgumentException {        throw new IllegalArgumentException(msg);    }}