Java URL Download downloadDirectory(URL dirUrl, File destDir)

Description

Downloads url directory to target directory (url directory will be subdirectory of target directory); example: dowloadDirectory(new URL("http://dir0/dir1/dir2"), new File("/home/junk")) behaves like cp -r dir2 /home/junk/dir2 such that the directory /home/junk/dir2 exists with all its sub dirs and files.

License

Apache License

Parameter

Parameter	Description
dirUrl	a parameter
destDir	a parameter

Exception

Parameter	Description
IOException	an exception

Declaration

public static void downloadDirectory(URL dirUrl, File destDir) throws IOException

Method Source Code

//package com.java2s;
/*/*from  ww  w  .  ja  v  a 2 s  .c o  m*/
 * Copyright 2009 the original author or authors.
 * Copyright 2009 SorcerSoft.org.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.BufferedReader;

import java.io.File;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.io.Reader;

import java.net.URL;

import java.net.URLConnection;

import java.util.Scanner;

import java.util.Vector;

public class Main {
    /**
     * Downloads url directory to target directory (url directory will be 
     * subdirectory of target directory); example:
     * 
     * dowloadDirectory(new URL("http://dir0/dir1/dir2"), new File("/home/junk"))
     * 
     * behaves like
     * 
     * cp -r dir2 /home/junk/dir2
     * 
     * such that the directory /home/junk/dir2 exists with all its sub dirs and 
     * files.
     * 
     * 
     * @param dirUrl
     * @param destDir
     * @throws IOException
     */
    public static void downloadDirectory(URL dirUrl, File destDir) throws IOException {

        if (!destDir.exists())
            throw new IOException(destDir + " does not exist.");
        if (!destDir.isDirectory())
            throw new IOException(destDir + " is not a directory.");

        Vector<String> dirListing = getFileContents(dirUrl);
        //printVect(dirListing);

        String urlDirName = (new File(dirUrl.getFile()).getName());
        File destDir2 = new File(destDir, urlDirName);
        //System.out.println("destDir2 = " + destDir2);

        for (String line : dirListing) {
            String[] fields = line.split("\\s");
            //System.out.println("==============================");
            //printArray(fields);

            //System.out.println("fields[0] = " +  fields[0]);
            //System.out.println("dirUrl.getFile() = " +  dirUrl.getFile());

            String fileField = fields[0].replace("\\", "/");
            String[] fileFieldArray = fileField.split("/");

            String filename = fileFieldArray[fileFieldArray.length - 1];
            //System.out.println("filename = " +  filename);
            URL fileUrl = new URL(dirUrl.toString() + "/" + filename);
            //System.out.println("fileUrl = " + fileUrl);

            boolean madeDirs = destDir2.mkdirs();
            //System.out.println(madeDirs + ": made " + destDir2);
            destDir2.setWritable(true);
            destDir2.setReadable(true);
            destDir2.setExecutable(true);

            if (fields[1].equals("f")) {
                File fileTarget = new File(destDir2, new File(fileUrl.getFile()).getName());
                //System.out.println("downloading " + fileUrl + " to " + fileTarget);
                download(fileUrl, fileTarget);
            }
            if (fields[1].equals("d")) {
                downloadDirectory(fileUrl, destDir2);
            }
        }

    }

    /**
     * This method was originally implemented by S. A. Burton, but has been
     * rewritten by E. D. Thompson in a a cleaner more efficient syntax. The
     * function gets the path to a file with the path file as an argument and
     * returns the file's contents in a vector of strings where each element of
     * the vector corresponds to a line in the file.
     * 
     * @param file
     *            Path to the file
     * @return Vector containing the file at the path file contents
     * 
     * @author E. D. Thompson, S. A. Burton
     * @throws FileNotFoundException
     */
    public static Vector<String> getFileContents(File file) throws FileNotFoundException {
        Vector<String> fileContents = null;
        // Check if file exist
        if (file.exists()) {
            // Creating a vector of strings
            fileContents = new Vector<String>();
            // Creating a input stream
            Scanner fin = new Scanner(new FileReader(file));
            String line;
            // Looping over files lines while there are lines to loop over
            while (fin.hasNext()) {
                line = fin.nextLine();
                fileContents.add(line);
            }
            // Closing file input stream
            fin.close();
        } else {
            // File not found
            System.out.printf("getFileContents:\nFile, %s, does not exist. Returning a NULL vector of strings\n",
                    file.getAbsolutePath());
        }
        return fileContents;
    }

    public static Vector<String> getFileContents(URL url) throws IOException {
        URLConnection myConnect = url.openConnection();
        myConnect.setDoInput(true);
        myConnect.setDoOutput(true);
        myConnect.setUseCaches(false);
        InputStreamReader iSR = new InputStreamReader(myConnect.getInputStream());

        BufferedReader bR = new BufferedReader((Reader) iSR);
        boolean eof = false;
        Vector<String> fileContents = new Vector<String>();

        while (!eof) {
            String line = bR.readLine();
            if (line == null) {
                eof = true;
            } else {
                fileContents.add(line);
            }
        }
        bR.close();
        return fileContents;
    }

    /**
     * This method given a URL sourceURL and file path destinationFile writes
     * the contents of the URL to file.
     * 
     * @param sourceUrl
     *            Source URL
     * @param destinationFile
     *            Destination file
     * @see writeUrlToFile
     * @throws IOException
     */
    public static void download(URL sourceUrl, File destinationFile) throws IOException {
        writeUrlToFile(sourceUrl, destinationFile);
    }

    /**
     * Method that writes the content of URL inputURL to file path
     * locatlInputFile
     * 
     * @param inputUrl
     *            Input URL
     * @param localInputFile
     *            File path
     * @throws IOException
     */
    public static void writeUrlToFile(URL inputUrl, File localInputFile) throws IOException {
        InputStream is = inputUrl.openStream();
        redirectInputStream2File(is, localInputFile);
    }

    /**
     * This method redirects an input stream to a file
     * 
     * @param is Input stream
     * @param file File
     * @throws IOException
     */
    public static void redirectInputStream2File(InputStream is, File file) throws IOException {
        int bufferSize = 4096;
        FileOutputStream fos = new FileOutputStream(file);
        byte[] buffer = new byte[bufferSize];
        int bytesRead;
        while ((bytesRead = is.read(buffer)) != -1) { // EOF
            fos.write(buffer, 0, bytesRead);
        }
        fos.close();
        is.close();
    }
}