Android Directory Clean cleanDirectory(File directory)

Description

Cleans a directory without deleting it.

Parameter

Parameter	Description
directory	directory to clean

Exception

Parameter	Description
IOException	in case cleaning is unsuccessful

Declaration

public static void cleanDirectory(File directory) throws IOException 

Method Source Code

//package com.java2s;

import java.io.File;
import java.io.FileNotFoundException;

import java.io.IOException;

public class Main {
    /**/*  w w  w  . ja v a2s. co m*/
     * Cleans a directory without deleting it.
     *
     * @param directory directory to clean
     * @throws IOException in case cleaning is unsuccessful
     */
    public static void cleanDirectory(File directory) throws IOException {
        if (!directory.exists()) {
            String message = directory + " does not exist";
            throw new IllegalArgumentException(message);
        }

        if (!directory.isDirectory()) {
            String message = directory + " is not a directory";
            throw new IllegalArgumentException(message);
        }

        File[] files = directory.listFiles();
        if (files == null) { // null if security restricted
            throw new IOException("Failed to list contents of " + directory);
        }

        IOException exception = null;
        for (int i = 0; i < files.length; i++) {
            File file = files[i];
            try {
                forceDelete(file);
            } catch (IOException ioe) {
                exception = ioe;
            }
        }

        if (null != exception) {
            throw exception;
        }
    }

    /**
     * Deletes a file. If file is a directory, delete it and all sub-directories.
     * <p>
     * The difference between File.delete() and this method are:
     * <ul>
     * <li>A directory to be deleted does not have to be empty.</li>
     * <li>You get exceptions when a file or directory cannot be deleted.
     *      (java.io.File methods returns a boolean)</li>
     * </ul>
     *
     * @param file  file or directory to delete, must not be <code>null</code>
     * @throws NullPointerException if the directory is <code>null</code>
     * @throws FileNotFoundException if the file was not found
     * @throws IOException in case deletion is unsuccessful
     */
    public static void forceDelete(File file) throws IOException {
        if (file.isDirectory()) {
            deleteDirectory(file);
        } else {
            boolean filePresent = file.exists();
            if (!file.delete()) {
                if (!filePresent) {
                    throw new FileNotFoundException("File does not exist: "
                            + file);
                }
                String message = "Unable to delete file: " + file;
                throw new IOException(message);
            }
        }
    }

    /**
     * Deletes a directory recursively. 
     *
     * @param directory  directory to delete
     * @throws IOException in case deletion is unsuccessful
     */
    public static void deleteDirectory(File directory) throws IOException {
        if (!directory.exists()) {
            return;
        }

        cleanDirectory(directory);
        if (!directory.delete()) {
            String message = "Unable to delete directory " + directory
                    + ".";
            throw new IOException(message);
        }
    }
}

Related

1. cleanDirectory(File directory)
2. cleanDirectory(String directory)
3. cleanDirectory(final File directory)
4. clearDir(String dirPath)