我正在开发一个 Android应用程序,其webview指向另一个团队的动态网站. 当我下载一个文件(主要是动态重定向的PDF和ZIP)时,我得到的是下载文件夹中的一个文件,其中包含一些HTML代码,其中包
当我下载一个文件(主要是动态重定向的PDF和ZIP)时,我得到的是下载文件夹中的一个文件,其中包含一些HTML代码,其中包含“用户不允许读取文件”的消息,无论我如何实现下载,我尝试：
> DownloadManager
>意图(让外部浏览器管理下载)
>“手工”(AsyncTask和httpconnection ……)
都具有相同的结果.
使用普通浏览器导航下载工作正常,无论是在台式PC,Android还是iOS设备上.
为什么webview不能访问文件？
可能是一个会话问题？ http端口？
我真的需要一些想法……
另一个提示：当从同一个链接下载两次文件时,该链接将重定向到同一个文件,但会产生两个不同的文件名…
编辑：我没有将webView指向网络应用程序,而是试图指向一个带有链接重定向的常见网页来下载另一个文件,好吧,只是它的工作原理.
以下是webview.setDownloadListener – onDownloadStart()参数：
userAgent=Mozilla/5.0 (Linux; Android 4.4.2; Nexus 7 Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/30.0.0.0 Safari/537.36 contentDisposition=attachment; filename=correct_filename.pdf, url=http://www.xxx.xx/site/downloadfile.wplus?REDIRECTFILE=D-507497120&ID_COUNTOBJ=ce_5_home&TYPEOBJ=CExFILE&LN=2 mimeType=application/octet-stream
这是一些代码
wv.getSettings().setSupportMultipleWindows(true);
wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
wv.getSettings().setAllowFileAccess(true);
wv.getSettings().setJavaScriptEnabled(true);
wv.getSettings().setBuiltInZoomControls(true);
wv.getSettings().setDisplayZoomControls(false);
wv.getSettings().setLoadWithOverviewMode(true);
wv.getSettings().setUseWideViewPort(true);
wv.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength){
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setDescription("Download file...");
request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimetype));
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); //Notify client once download is completed!
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(url, contentDisposition, mimetype));
DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
dm.enqueue(request);
Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
}
}
编辑二
这是我在尝试“手动”下载文件时使用的代码：
onDownloadStart()是我调用downloadFileAsync()的地方：
public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimeType, long contentLength) {
String fileName;
try {
fileName = URLUtil.guessFileName(url, contentDisposition, mimeType);
downloadFileAsync(url, fileName);
}catch (Exception e){
}
}
这是AsyncTask：
private void downloadFileAsync(String url, String filename){
new AsyncTask<String, Void, String>() {
String SDCard;
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... params) {
try {
URL url = new URL(params[0]);
HttpURLConnection urlConnection = null;
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.connect();
int lengthOfFile = urlConnection.getContentLength();
//SDCard = Environment.getExternalStorageDirectory() + File.separator + "downloads";
SDCard = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)+"";
int k = 0;
boolean file_exists;
String finalValue = params[1];
do {
if (k > 0) {
if (params[1].length() > 0) {
String s = params[1].substring(0, params[1].lastIndexOf("."));
String extension = params[1].replace(s, "");
finalValue = s + "(" + k + ")" + extension;
} else {
String fileName = params[0].substring(params[0].lastIndexOf('/') + 1);
String s = fileName.substring(0, fileName.lastIndexOf("."));
String extension = fileName.replace(s, "");
finalValue = s + "(" + k + ")" + extension;
}
}
File fileIn = new File(SDCard, finalValue);
file_exists = fileIn.exists();
k++;
} while (file_exists);
File file = new File(SDCard, finalValue);
FileOutputStream fileOutput = null;
fileOutput = new FileOutputStream(file, true);
InputStream inputStream = null;
inputStream = urlConnection.getInputStream();
byte[] buffer = new byte[1024];
int count;
long total = 0;
while ((count = inputStream.read(buffer)) != -1) {
total += count;
//publishProgress(""+(int)((total*100)/lengthOfFile));
fileOutput.write(buffer, 0, count);
}
fileOutput.flush();
fileOutput.close();
inputStream.close();
} catch (MalformedURLException e){
} catch (ProtocolException e){
} catch (FileNotFoundException e){
} catch (IOException e){
} catch (Exception e){
}
return params[1];
}
@Override
protected void onPostExecute(final String result) {
}
}.execute(url, filename);
}
取自How to download a PDF from a dynamic URL in a webview
感谢名单
最后我决定寻找DownloadHandler from the Android Stock Browser code.
我的代码中唯一明显的缺点是cookie(!!!).
这是我的最终工作版本(DownloadManager方法)：
wv.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimeType, long contentLength) {
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setMimeType(mimeType);
//------------------------COOKIE!!------------------------
String cookies = CookieManager.getInstance().getCookie(url);
request.addRequestHeader("cookie", cookies);
//------------------------COOKIE!!------------------------
request.addRequestHeader("User-Agent", userAgent);
request.setDescription("Downloading file...");
request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimeType));
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(url, contentDisposition, mimeType));
DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
dm.enqueue(request);
Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
}
});