Question

我能够解析xml文件，我想通过xml下载给定url的文件。我有以下代码：

    try{
        /* Create a URL we want to load some xml-data from. */
        URL url = new URL("http://dev2.eacomm.com/tabletcms/tablets/sync_login/jayem30/jayem");
        url.openConnection();
        /* Get a SAXParser from the SAXPArserFactory. */
        SAXParserFactory spf = SAXParserFactory.newInstance();
        SAXParser sp = spf.newSAXParser();

        /* Get the XMLReader of the SAXParser we created. */
        XMLReader xr = sp.getXMLReader();
        /* Create a new ContentHandler and apply it to the XML-Reader*/
        ExampleHandler myExampleHandler = new ExampleHandler();
        xr.setContentHandler(myExampleHandler);

        /* Parse the xml-data from our URL. */
        xr.parse(new InputSource(url.openStream()));
        /* Parsing has finished. */

        /* Our ExampleHandler now provides the parsed data to us. */
        List<ParsedExampleDataSet> parsedExampleDataSet = myExampleHandler.getParsedData();

        Iterator i;
        i = parsedExampleDataSet.iterator();
        ParsedExampleDataSet dataItem;

        while(i.hasNext()){
                dataItem = (ParsedExampleDataSet) i.next();
                String folder = dataItem.getParentTag();

                if( folder == "Videos"  ){

                    String [] videoName = dataItem.getName().split("/");
                    String currentFile = videoName[0] + "." + videoName[1];
                    String currentFileURL = dataItem.getUrl() + videoName[0] + "." + videoName[1];
                    tv.append("\nURL: " + currentFileURL);


                    new DownloadFileAsync().execute(currentFile , currentFileURL, "Videos");
                    this.videoCount++;
                    tv.append("\nVideo Count: " + this.videoCount );
                }

                if( folder == "Slideshows" ){
                    //processSlideshows(dataItem, folder);   
                }      
        }

    }catch(Exception e){
        Toast.makeText(getBaseContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
    }

下载代码在异步任务上。但是，当我运行它时，我下载的两个文件（126kb和98kb）被下载，文件在那里，但它们的大小都只有1kb。该文件无法播放。

当我更改行

时

**new DownloadFileAsync().execute(currentFile , currentFileURL, "Videos");** 
to 
**new DownloadFileAsync().execute("hehe.flv", "http://dev2.eacomm.com/tabletcms/app/webroot/files/000002/videos/27.flv", "Videos");**

文件大小正常，但只返回一个文件。

编辑：

//---------------------------- START DownloadFileAsync -----------------------//
class DownloadFileAsync extends AsyncTask<String, String, String>{

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

    @Override
    protected String doInBackground(String... strings) {

        try {
            String currentFile = strings[0];
            String currentFileURL = strings[1];
            String folder = strings[2];

            File root = Environment.getExternalStorageDirectory();
            URL u = new URL(currentFileURL);
            HttpURLConnection c = (HttpURLConnection) u.openConnection();
            c.setRequestMethod("GET");
            c.setDoOutput(true);
            c.connect();

            int lenghtOfFile = c.getContentLength();

            FileOutputStream f = new FileOutputStream(new File(root + "/Engagia/Downloads/" + folder, currentFile));

            InputStream in = c.getInputStream();

            byte[] buffer = new byte[1024];
            int len1 = 0;
            long total = 0;

            while ((len1 = in.read(buffer)) > 0) {
                total += len1; //total = total + len1
                publishProgress("" + (int)((total*100)/lenghtOfFile));
                f.write(buffer, 0, len1);
            }
            f.close();
        }catch (Exception e){
            Log.d("Downloader", e.getMessage());
        }
        return null;
    }

    protected void onProgressUpdate(String... progress) {
        Log.d("ANDRO_ASYNC",progress[0]);
        mProgressDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String unused) {
        dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

}
//---------------------------- END DownloadFileAsync -----------------------//

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
        case DIALOG_DOWNLOAD_PROGRESS:
            mProgressDialog = new ProgressDialog(this);
            mProgressDialog.setMessage("Downloading files...");
            mProgressDialog.setIndeterminate(false);
            mProgressDialog.setMax(100);
            mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            mProgressDialog.setCancelable(true);
            mProgressDialog.show();
            return mProgressDialog;
        default:
            return null;
    }

}

编辑:(感谢Haphazard）

我的不好，我重新检查了我的网址，发现我的XML流没有返回正确的下载网址，所以我不得不重新构建一个URL供下载。我做了类似的事情：

tv.append("\nCurrent File URL: " + currentFileURL);
String downloadFileURL = currentFileURL.replace( "tablets/tablet_content", "app/webroot/files" );

Answer 1

确保您的网址形式正确。您确认currentFile和currentFileURL都正确吗？

Answer 2

您可以发布异步任务中的代码吗？我觉得问题是从网址下载文件。

请参阅以下网址以了解如何下载文件。

ANDROID: How do I download a video file to SD card?

由于迪帕克

Answer 3

请尝试以下代码。

package com.endeavour.sampleprograms;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.util.ByteArrayBuffer;

import android.os.AsyncTask;
import android.os.Environment;

class DownloadFileAsync extends AsyncTask<String, String, String>{

    private static final String DIALOG_DOWNLOAD_PROGRESS = null;
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
//        showDialog(DIALOG_DOWNLOAD_PROGRESS);
    }

    @Override
    protected String doInBackground(String... strings) {

        try {
            String currentFile = strings[0];
            String currentFileURL = strings[1];
            String folder = strings[2];
*emphasized text*
            String fileName = Environment.getExternalStorageDirectory() + "/Engagia/Downloads/" + folder+"/";
            File wallpaperDirectory = new File(fileName);
            if (!wallpaperDirectory.exists())
                wallpaperDirectory.mkdirs();
            fileName = fileName+currentFile;
            downloadFromUrl(currentFileURL, fileName);
            //            FileOutputStream f = new FileOutputStream(new File(root + "/Engagia/Downloads/" + folder, currentFile));

        }catch (Exception e){

        }
        return null;
    }


    public void downloadFromUrl(String VideoURL, String fileName) {  //this is the downloader method
        try {
            System.out.println("....Url....."+VideoURL);
                URL url = new URL(VideoURL); //you can write here any link
                File file = new File(fileName);

                long startTime = System.currentTimeMillis();
                              /* Open a connection to that URL. */
                URLConnection ucon = url.openConnection();

                /*
                 * Define InputStreams to read from the URLConnection.
                 */
                InputStream is = ucon.getInputStream();
                BufferedInputStream bis = new BufferedInputStream(is);

                /*
                 * Read bytes to the Buffer until there is nothing more to read(-1).
                 */
                ByteArrayBuffer baf = new ByteArrayBuffer(50);
                int current = 0;
                while ((current = bis.read()) != -1) {
                        baf.append((byte) current);
                }

                /* Convert the Bytes read to a String. */
                FileOutputStream fos = new FileOutputStream(file);
                fos.write(baf.toByteArray());
                fos.close();


        } catch (IOException e) {
               e.printStackTrace();
        }
    }




}

谢谢Deepak

Android：100+ KB的文件下载变为1 KB

3 个答案: