我想从Android的Zippyshare网站下载文件。
问题是返回的内容长度为-1。因此，我无法下载有效的文件。
这是我的代码
public class DownloadFileDemo1 extends Activity {
ProgressBar pb;
Dialog dialog;
int downloadedSize = 0;
int totalSize = 0;
TextView cur_val;
String dwnload_file_path = "http://www17.zippyshare.com/i/95748527/55444/image.jpeg";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
showProgress(dwnload_file_path);
new Thread(new Runnable() {
public void run() {
downloadFile();
}
}).start();
}
void downloadFile(){
try {
URL url = new URL(dwnload_file_path);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestProperty("Accept-Encoding", "gzip");
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//connect
urlConnection.connect();
//set the path where we want to save the file
File SDCardRoot = Environment.getExternalStorageDirectory();
//create a new file, to save the downloaded file
File file = new File(SDCardRoot,"downloaded_file.png");
FileOutputStream fileOutput = new FileOutputStream(file);
//Stream used for reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
System.out.println("ENCODING"+urlConnection.getContentEncoding());
if ("gzip".equals(urlConnection.getContentEncoding())) {
inputStream = new GZIPInputStream(inputStream);
}
InputSource is = new InputSource(inputStream);
//this is the total size of the file which we are downloading
totalSize = urlConnection.getContentLength();
runOnUiThread(new Runnable() {
public void run() {
pb.setMax(totalSize);
}
});
//create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
fileOutput.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
// update the progressbar //
runOnUiThread(new Runnable() {
public void run() {
pb.setProgress(downloadedSize);
float per = ((float)downloadedSize/totalSize) * 100;
cur_val.setText("Downloaded " + downloadedSize + "KB / " + totalSize + "KB (" + (int)per + "%)" );
}
});
}
//close the output stream when complete //
fileOutput.close();
runOnUiThread(new Runnable() {
public void run() {
// pb.dismiss(); // if you want close it..
}
});
} catch (final MalformedURLException e) {
showError("Error : MalformedURLException " + e);
e.printStackTrace();
} catch (final IOException e) {
showError("Error : IOException " + e);
e.printStackTrace();
}
catch (final Exception e) {
showError("Error : Please check your internet connection " + e);
}
}
void showError(final String err){
runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(DownloadFileDemo1.this, err, Toast.LENGTH_LONG).show();
}
});
}
void showProgress(String file_path){
dialog = new Dialog(DownloadFileDemo1.this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.myprogressdialog);
dialog.setTitle("Download Progress");
TextView text = (TextView) dialog.findViewById(R.id.tv1);
text.setText("Downloading file from ... " + file_path);
cur_val = (TextView) dialog.findViewById(R.id.cur_pg_tv);
cur_val.setText("Starting download...");
dialog.show();
pb = (ProgressBar)dialog.findViewById(R.id.progress_bar);
pb.setProgress(0);
pb.setProgressDrawable(getResources().getDrawable(R.drawable.green_progress));
}
}
我怎么解决这个问题？
最佳答案
根据getContentLength的文档：
返回响应头指定的内容长度（以字节为单位）
字段content-length；如果未设置或不能设置为-1，则为-1
表示为int。
如果您将检查链接here，则会发现未设置“内容长度”。
（我要补充一点，我没有完全检查您的代码，但是通常在带有缓冲区的主下载循环中-正在下载某些内容，但是我没有检查它是否正确）
编辑：我要'讨厌'家伙，那给了我'-1'。我正在帮助详细链接以及如何进行检查，为什么内容长度返回-1，并且有人给我否定的信息。我更改了一点downloadFile函数，仅用于下载文件，而不更新UI，然后我们得到了：
void downloadFile(){
try {
URL url = new URL(dwnload_file_path);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestProperty("Accept-Encoding", "gzip");
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
//connect
urlConnection.connect();
//set the path where we want to save the file
//create a new file, to save the downloaded file
File file = new File("downloaded_file.png");
FileOutputStream fileOutput = new FileOutputStream(file);
//Stream used for reading the data from the internet
InputStream inputStream = urlConnection.getInputStream();
System.out.println("ENCODING"+urlConnection.getContentEncoding());
if ("gzip".equals(urlConnection.getContentEncoding())) {
inputStream = new GZIPInputStream(inputStream);
}
InputSource is = new InputSource(inputStream);
//this is the total size of the file which we are downloading
totalSize = urlConnection.getContentLength();
//create a buffer...
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
fileOutput.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
// update the progressbar //
}
//close the output stream when complete //
fileOutput.close();
} catch (final MalformedURLException e) {
e.printStackTrace();
} catch (final IOException e) {
e.printStackTrace();
}
catch (final Exception e) {
e.printStackTrace();
}
}
当我检查此代码正在下载文件时，但这不是此图像，而是zippyshare的html页面，因为zippy具有某种保护作用，可以从其站点下载文件。