我正在开发的应用程序支持Android 2.3向上。由于下载管理器不支持2.3中的https（我无法理解为什么），我正在实现自己的版本。
我遇到的问题是如果android在下载内容时更改网络（wifi到3g等）我收到以下错误。
06-14 17:26:48.770: W/System.err(15648): javax.net.ssl.SSLException: Read error: ssl=0x270420: I/O error during system call, Connection timed out
06-14 17:26:48.770: W/System.err(15648): at org.apache.harmony.xnet.provider.jsse.NativeCrypto.SSL_read(Native Method)
06-14 17:26:48.770: W/System.err(15648): at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl$SSLInputStream.read(OpenSSLSocketImpl.java:788)
06-14 17:26:48.770: W/System.err(15648): at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:103)
06-14 17:26:48.770: W/System.err(15648): at org.apache.http.impl.io.AbstractSessionInputBuffer.read(AbstractSessionInputBuffer.java:134)
06-14 17:26:48.770: W/System.err(15648): at org.apache.http.impl.io.ContentLengthInputStream.read(ContentLengthInputStream.java:174)
06-14 17:26:48.770: W/System.err(15648): at org.apache.http.impl.io.ContentLengthInputStream.read(ContentLengthInputStream.java:188)
06-14 17:26:48.770: W/System.err(15648): at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:178)
06-14 17:26:48.770: W/System.err(15648): at java.io.BufferedInputStream.fillbuf(BufferedInputStream.java:140)
06-14 17:26:48.770: W/System.err(15648): at java.io.BufferedInputStream.read(BufferedInputStream.java:324)
06-14 17:26:48.770: W/System.err(15648): at java.io.FilterInputStream.read(FilterInputStream.java:133)
06-14 17:26:48.770: W/System.err(15648): at net.doo.download.ManualDocDownloader$AsyncDocDownloader.doInBackground(ManualDocDownloader.java:126)
06-14 17:26:48.770: W/System.err(15648): at net.doo.download.ManualDocDownloader$AsyncDocDownloader.doInBackground(ManualDocDownloader.java:86)
06-14 17:26:48.770: W/System.err(15648): at android.os.AsyncTask$2.call(AsyncTask.java:185)
06-14 17:26:48.770: W/System.err(15648): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
06-14 17:26:48.780: W/System.err(15648): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
06-14 17:26:48.780: W/System.err(15648): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
06-14 17:26:48.840: W/System.err(15648): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
06-14 17:26:48.845: W/System.err(15648): at java.lang.Thread.run(Thread.java:1019)
遇到问题的代码看起来像这样......
public class AsyncDocDownloader extends AsyncTask<String, Integer, Boolean> {
private int id;
private Notification notification;
public AsyncDocDownloader(int id, Notification notification) {
this.id = id;
this.notification = notification;
}
@Override
protected void onProgressUpdate(Integer... values) {
notification.contentView.setProgressBar(R.id.status_progress, 100, values[0], false);
notificationManager.notify(id, notification);
}
@Override
protected Boolean doInBackground(String... values) {
try {
HttpGet get = new HttpGet(values[0]);
HttpResponse resp = httpClientProvider.get().execute(get, context);
File dooDirectory = directoryProvider.get();
File fileName = new File(dooDirectory, values[1]);
InputStream input = new BufferedInputStream(resp.getEntity().getContent());
OutputStream output = new FileOutputStream(fileName);
int fileLength = Integer.valueOf(resp.getHeaders("Content-Length")[0].getValue());
int step = fileLength/20;
int counter = 0;
int progress = 0;
byte data[] = new byte[1024];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
if(total > counter){
progress = progress + 5;
publishProgress(progress);
counter = step + counter;
}
output.write(data, 0, count);
}
output.close();
input.close();
Log.d("DownloadDoc", "Completed download");
return true;
} catch (IOException e) {
Log.d("DownloadDoc", "IOException");
e.printStackTrace();
return false;
}
}
@Override
protected void onPostExecute(Boolean success) {
Log.d("DownloadDoc", "onPostExecute Called");
if (success) {
Intent i = new Intent(DownloadManager.ACTION_DOWNLOAD_COMPLETE);
application.sendBroadcast(i);
} else {
notification.flags = notification.flags | Notification.DEFAULT_ALL;
notification.contentView.setTextViewText(R.id.status_text, "failed");
notificationManager.notify(id, notification);
}
}
}
通过提供程序传递的httpClient配置如下（提供程序是因为我使用的是roboguice）
HttpParams params = new BasicHttpParams();
HttpRequestRetryHandler retryhandler = new DefaultHttpRequestRetryHandler(6, true);
// The params are read in the ctor of the pool constructed by
// ThreadSafeClientConnManager, and need to be set before constructing it.
ConnManagerParams.setMaxTotalConnections(params, 200);
ConnPerRoute cpr = new ConnPerRoute() {
@Override
public int getMaxForRoute(HttpRoute httpRoute) {
return 50;
}
};
ConnManagerParams.setMaxConnectionsPerRoute(params, cpr);
SSLSocketFactory socketFactory = SSLSocketFactory.getSocketFactory();
SchemeRegistry schemeRegistry = new SchemeRegistry();
schemeRegistry.register(
new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
schemeRegistry.register(new Scheme("https", SSLCertificateSocketFactory.getHttpSocketFactory(50000,
new SSLSessionCache(context)), 443));
ClientConnectionManager conManager = new ThreadSafeClientConnManager(params, schemeRegistry);
DefaultHttpClient httpClient = new DefaultHttpClient(conManager, new BasicHttpParams());
httpClient.setHttpRequestRetryHandler(retryhandler);
感谢您的任何建议
答案 0 :(得分：2)
06-14 17:26:48.770: W/System.err(15648): at net.doo.download.ManualDocDownloader$AsyncDocDownloader.doInBackground(ManualDocDownloader.java:126)
06-14 17:26:48.770: W/System.err(15648): at net.doo.download.ManualDocDownloader$AsyncDocDownloader.doInBackground(ManualDocDownloader.java:86)
这表示您的代码抛出了异常，然后try {} catch（）会向上传播。
您应该尝试捕获SSLException以及IOException，以便您可以优雅地恢复并重新启动AsyncTask