将文件从URL下载到FOLDER

Question

         java.io.BufferedInputStream in = new java.io.BufferedInputStream(new

                             java.net.URL(args[1].toString()).openStream());
                             java.io.FileOutputStream fos = new java.io.FileOutputStream("WorldEdit/schematics/"+args[2].toString());
                             java.io.BufferedOutputStream bout = new BufferedOutputStream(fos,1024);
                             byte data[] = new byte[1024];

                             while(in.read(data,0,1024)>=0)
                             {
                             bout.write(data);
                             }
                             bout.close();
                             in.close();
                             }

I want this to download a file from a url, and put it into a folder. This program will be in a folder named "plugins" where I want to put the downloaded file is in "plugins/WorldEdit/schematic". Doesn't seem to work. Any suggestions?

Answer 1

in.read returns a number indicating how many bytes were actually read. You are ignoring that number and assuming 1024 bytes are read on each call.

If you are using Java 7, you can save a URL to a file this way:

try (InputStream in = new URL(args[1].toString()).openStream()) {
    Files.copy(in, Paths.get("WorldEdit", "schematics", args[2].toString()));
}

In Java 6 (and 5 and 4), you can use channels:

FileChannel fileChannel = fos.getChannel();
ReadableByteChannel urlChannel = Channels.newChannel(
    new URL(args[1].toString()).openStream());
fileChannel.transferFrom(urlChannel, 0, Long.MAX_VALUE);

Answer 2

You can refer the following program and edit according to your needs. In this program url is fetching from a table in an html file using Jsoup to parse the html file and downloading into different folder..path of the folder I took from the table(table has 3 column filename,path,download link) .

Go to downloadFile(String urlString) method,there you can find the answer for your question

    import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author nudanesh
 */
public class URLDownload {

    private Document doc;
    String url = "", folder, file;
    private final File sourceFile;
    int i = 1;
    int r = 1, c = 1;
    int anchorCol = 3;
    Library lib;

    URLDownload() {
        lib = new Library();
        sourceFile = new File("Download.html");
        try {

            doc = Jsoup.parse(sourceFile, "UTF-8");
        } catch (IOException ex) {
            Logger.getLogger(URLDownload.class.getName()).log(Level.SEVERE, null, ex);
        }
        //Elements links = doc.select("a[href]");
        Elements rows = doc.select("tr");
        System.out.println("Size=" + rows.size());
        for (Element row : rows) {


                Elements cols = row.getElementsByTag("td");
                c = 1;
                for (Element col : cols) {
                    System.out.println("Row"+r);
                    if (c == 1) {
                        file = col.text();//System.out.println("File in main"+file);
                    } else if (c == 2) {
                        folder = col.text();//System.out.println("Folder in main"+folder);
                    } else {
                        try {
                            url = col.getElementsByTag("a").attr("href");
                        } catch (Exception e) {
                            System.out.print("-");
                        }
                    }

                    c++;
                }
                if (!url.equals("")) {
                    lib.setLocation(file,folder);
                    lib.downloadFile(url);
                }
                url = "";

            i++;
            r++;
        }
    }

    public static void main(String arg[]) {

        new URLDownload();
    }
}

and following is the Library class file

    import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.file.Files;
import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
/**
 *
 * @author nudanesh
 */
public class Library  {

    boolean downloaded = false;
    Thread t;
    int waitTime = 0;
    String baseLoc = "";
    int size = 1024, ByteWritten = 0;
    URL url;
    URLConnection uCon = null;
    String folderLoc = "", file = "firstFile.csv";
    File loc;
    private OutputStream outStream;
    private InputStream is=null;
    private byte[] buf;
    private int ByteRead;
    private int FolderInUrl = 4;
    private boolean rootFolder = true;
    private File resultFile;
    private FileOutputStream fileResult;
    private XSSFWorkbook workbookResult;
    private XSSFSheet sheetResult;
    private int updateExcelRowNum = -1;
    private int updateExcelColNum = -1;
    String date;
    private int waitLimit = 900000;

    Library() {
        /*System.out.print(Calendar.getInstance().toString());
         Date d=new Date();
         String date=d.toString();
         System.out.println(date);*/

        //t = new Thread(this);
       // t.start();

        date = new SimpleDateFormat("yyyy_MM_dd_HH_mm_ss").format(Calendar.getInstance().getTime());
        System.out.print(date);
        baseLoc = date + "/";
        WriteDataToExcel();
        baseLoc += "Business Reports/";
        createRowExcel(updateExcelRowNum);
        updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Report Name");
        updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Path");
        updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Status");
        updateExcel();
    }

    public void setLocation(String a, String b) {
        file = a;
        file += ".csv";
        folderLoc = baseLoc + getFolderPath(b);

   // System.out.println("File Name: "+file);
        // System.out.println("Folder loc: "+folderLoc);
    }

    public String getFolderPath(String b) {
        String path = "";
        try {
            System.out.println("path" + b);
            path = b;
            // path = java.net.URLDecoder.decode(b, "UTF-8");
            String p[] = path.split("/");
            path = "";
            for (int i = FolderInUrl; i < p.length - 1; i++) {
                rootFolder = false;
                p[i] = removeSpacesAtEnd(p[i]);

                path = path + p[i] + "/";
            }

        } catch (Exception ex) {
            Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
        }
        return path;
    }

    public void downloadFile(String urlString) {
        // System.out.println("Started");
        try {
            url = new URL(urlString);
        } catch (MalformedURLException ex) {
            Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            loc = new File(folderLoc);
            if (!loc.exists()) {
                loc.mkdirs();
            }


            outStream = new BufferedOutputStream(new FileOutputStream(folderLoc + file));
            uCon = url.openConnection();
        uCon.setReadTimeout(waitLimit);
                is = uCon.getInputStream();
               downloaded=true;
            buf = new byte[size];

            while ((ByteRead = is.read(buf)) != -1) {
                System.out.println("while executing" + ByteRead);
                outStream.write(buf, 0, ByteRead);
                ByteWritten += ByteRead;
            }

            //System.out.println("Downloaded" + ByteWritten);
            resetCounters();
            createRowExcel(updateExcelRowNum);
            updateRowColExcel(updateExcelRowNum, updateExcelColNum, file);
            updateRowColExcel(updateExcelRowNum, updateExcelColNum, folderLoc);
            if (ByteWritten < 1000) {
                updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Downloaded ");
            } else {
                updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Downloaded ");
            }
            updateExcel();
        } catch (Exception e) {
            System.out.println("error catch" + e);
            resetCounters();
            createRowExcel(updateExcelRowNum);
            updateRowColExcel(updateExcelRowNum, updateExcelColNum, file);
            updateRowColExcel(updateExcelRowNum, updateExcelColNum, folderLoc);
            updateRowColExcel(updateExcelRowNum, updateExcelColNum, "Rejected the Download after waiting " + (waitLimit / 60000) + " minutes");
            updateExcel();
            waitTime = 0;
        } finally {
            try {
                System.out.println("Error in streams");
                if(downloaded)
                is.close();
                outStream.close();
                downloaded= false;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public void moveToFolder(String reportName, String path) {

        try {
            File repo = new File(folderLoc + "/" + reportName + ".csv");
            path = folderLoc + "/" + path;
            File pathFolder = new File(path);
            if (!pathFolder.exists()) {
                pathFolder.mkdirs();
            }
            pathFolder = new File(path + reportName + ".csv");
            System.out.println("Path=" + pathFolder.getAbsolutePath() + "\nReport path=" + repo.getAbsolutePath());
            System.out.println("Source" + repo.getAbsolutePath());

            //System.out.println("Status" + repo.renameTo(new File(pathFolder.getAbsolutePath())));
            System.out.println("Status" + Files.move(repo.toPath(), new File(pathFolder.getAbsolutePath()).toPath(), REPLACE_EXISTING));
//Files.

        } catch (Exception e) {
            System.out.println("error while moving" + e);
        }

    }

    public String changeSpecialCharacters(String report) {

        report = report.replaceAll(":", "_");
        return report;
    }

    public String removeSpacesAtEnd(String inputPath) {

        for (int i = inputPath.length() - 1; i >= 0; i--) {
            if (inputPath.charAt(i) != ' ') {
                break;
            } else {
                System.out.println("Before string is" + inputPath);
                inputPath = inputPath.substring(0, i);
                System.out.println("AFter string is" + inputPath);
            }
        }

        return inputPath;
    }

    public void WriteDataToExcel() {

        try {
            // file = new FileInputStream(new File("config.xlsx"));

            //   File resultFolder = new File("Results");
            //   if (resultFolder.exists()) {
            //       deleteDirectory(resultFolder);
            //   }
            // resultFolder.mkdirs();
            if (!new File(baseLoc).exists()) {
                new File(baseLoc).mkdirs();
            }
            resultFile = new File(baseLoc + "Reports info " + date + ".xlsx");
            System.out.println("Path" + resultFile.getAbsolutePath());
            resultFile.createNewFile();
            // rFilePath = resultFile.getAbsolutePath();

            fileResult = new FileOutputStream(resultFile);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        //Get the workbook instance for XLS file
        //      System.out.println("file success");
        XSSFWorkbook workbook = null;

        try {

            workbookResult = new XSSFWorkbook();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("Opening the browser");
        //Get first sheet from the workbook

        sheetResult = workbookResult.createSheet();
        //sheetResult.set
        //Get iterator to all the rows in current sheet

        //Get iterator to all cells of current row
        //ar.add(folderLocation);
        //  ar.add(firefoxProfileLocation);
    }

    public void updateExcel() {
        try {
            //fileResult.close();

            fileResult = new FileOutputStream(resultFile);
            workbookResult.write(fileResult);
            fileResult.close();
        } catch (Exception e) {
            System.out.println(e);
        }

    }

    public void createRowExcel(int num) {
        updateExcelRowNum++;
        num = updateExcelRowNum;
        sheetResult.createRow(num);

    }

    public void updateRowColExcel(int rnum, int cnum, String value) {
        updateExcelColNum++;
        cnum = updateExcelColNum;
        sheetResult.getRow(rnum).createCell(cnum);
        XSSFCell cell = sheetResult.getRow(rnum).getCell(cnum);
        cell.setCellValue(value);

    }

    public void updateColumn(int rnum, int cnum, String value) {
        XSSFCell cell = sheetResult.getRow(rnum).getCell(cnum);
        cell.setCellValue(value);

    }

    public void resetCounters() {
        updateExcelColNum = -1;

    }

 /*   @Override
    public void run() {
        while (true) {
            if (true) {
                waitTime += 1000;
System.out.println(waitTime);
                if (waitTime > waitLimit) {
                    try {
                        is.close();
                        outStream.close();
                    //downloaded=false;
                        // cancelDownload=true;
                    } catch (Exception ex) {
                        Logger.getLogger(Library.class.getName()).log(Level.SEVERE, null, ex);
                    }

                }
            }
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
            }

        }
    }*/

}