我有一个简单的代码应该执行一项任务，当单击按钮下载文件，将其保存到SD卡，然后打开它。一切正常，除了在下载期间，对于较大的文件，连接丢失和进度条挂起 - 几乎总是在20％。我搜索并搜索过，无法弄清楚如何保持连接活动并允许下载完成。 有关如何保持连接处于活动状态的任何想法，以便下载完成而不是停滞在20％？
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class DownloadTestActivity extends Activity {
public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
private Button startBtn;
private ProgressDialog mProgressDialog;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mProgressDialog = new ProgressDialog(DownloadTestActivity.this);
mProgressDialog.setMessage("Downloading...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
startBtn = (Button) findViewById(R.id.startBtn);
startBtn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
startDownload();
}
});
}
private void startDownload() {
DownloadFile downloadFile = new DownloadFile();
downloadFile
.execute("http://www.website.com/file.pdf");
}
class DownloadFile extends AsyncTask<String, Integer, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog.show();
}
@Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
mProgressDialog.setProgress(progress[0]);
}
@Override
protected String doInBackground(String... aurl) {
try {
URL url = new URL(aurl[0]);
URLConnection connection = url.openConnection();
connection.connect();
int fileLength = connection.getContentLength();
Log.d("ANDRO_ASYNC", "Lenght of file: " + fileLength);
InputStream input = new BufferedInputStream(url.openStream());
String path = Environment.getExternalStorageDirectory()
+ "/Android/Data/"
+ getApplicationContext().getPackageName() + "/files";
File file = new File(path);
file.mkdirs();
File outputFile = new File(file, "test1.doc");
OutputStream output = new FileOutputStream(outputFile);
byte data[] = new byte[8192];
long total = 0;
int count;
while ((count = input.read(data)) != -1) {
total += count;
publishProgress((int) (total * 100 / fileLength));
output.write(data, 0, count);
}
output.flush();
output.close();
input.close();
showPdf();
} catch (Exception e) {
}
return null;
}
private void showPdf() {
// TODO Auto-generated method stub
if(mProgressDialog != null){
mProgressDialog.dismiss();
}
File file = new File(Environment.getExternalStorageDirectory()
+ "/Android/Data/"
+ getApplicationContext().getPackageName()
+ "/files/test1.doc");
PackageManager packageManager = getPackageManager();
Intent testIntent = new Intent(Intent.ACTION_VIEW);
testIntent.setType("application/msword");
List list = packageManager.queryIntentActivities(testIntent,
PackageManager.MATCH_DEFAULT_ONLY);
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(file);
intent.setDataAndType(uri, "application/msword");
startActivity(intent);
}
}
}
使用logcat信息进行编辑：
--------- beginning of /dev/log/system
W/InputManagerService( 199): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@4137b898
--------- beginning of /dev/log/main
D/AndroidRuntime(20673):
D/AndroidRuntime(20673): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
D/AndroidRuntime(20673): CheckJNI is OFF
D/AndroidRuntime(20673): Calling main entry com.android.commands.pm.Pm
D/AndroidRuntime(20673): Shutting down VM
D/dalvikvm(20673): GC_CONCURRENT freed 101K, 82% free 467K/2560K, paused 1ms+0ms
D/dalvikvm(20673): Debugger has detached; object registry had 1 entries
I/AndroidRuntime(20673): NOTE: attach of thread 'Binder Thread #3' failed
D/AndroidRuntime(20687):
D/AndroidRuntime(20687): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
D/AndroidRuntime(20687): CheckJNI is OFF
D/AndroidRuntime(20687): Calling main entry com.android.commands.am.Am
I/ActivityManager( 199): START {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.myapp/.Activity} from pid 20687
D/AndroidRuntime(20687): Shutting down VM
D/dalvikvm(20687): GC_CONCURRENT freed 102K, 81% free 489K/2560K, paused 0ms+0ms
D/jdwp (20687): Got wake-up signal, bailing out of select
D/dalvikvm(20687): Debugger has detached; object registry had 1 entries
I/AndroidRuntime(20687): NOTE: attach of thread 'Binder Thread #3' failed
D/dalvikvm(20698): Late-enabling CheckJNI
I/ActivityManager( 199): Start proc com.myapp for activity com.myapp/.Activity: pid=20698 uid=10102 gids={1015, 3003}
I/dalvikvm(20698): Turning on JNI app bug workarounds for target SDK version 10...
V/PhoneStatusBar( 271): setLightsOn(true)
D/AudioHardware( 98): AudioHardware pcm playback is going to standby.
D/AudioHardware( 98): closePcmOut_l() mPcmOpenCnt: 1
I/ActivityManager( 199): Displayed com.myapp/.Activity: +197ms
W/InputManagerService( 199): Starting input on non-focused client com.android.internal.view.IInputMethodClient$Stub$Proxy@4199ed28 (uid=10098 pid=20011)
I/ActivityManager( 199): START {cmp=com.myapp/.Choice} from pid 20698
D/AudioHardware( 98): AudioHardware pcm playback is exiting standby.
D/AudioHardware( 98): openPcmOut_l() mPcmOpenCnt: 0
V/PhoneStatusBar( 271): setLightsOn(true)
I/ActivityManager( 199): Displayed com.myapp/.Choice: +93ms
D/ANDRO_ASYNC(20698): Lenght of file: 736768
D/dalvikvm(20698): GC_CONCURRENT freed 103K, 3% free 9403K/9607K, paused 2ms+3ms
W/NetworkStats( 199): found non-monotonic values; saving to dropbox
D/dalvikvm( 199): JIT code cache reset in 5 ms (1048440 bytes 13/0)
D/dalvikvm( 199): GC_CONCURRENT freed 1472K, 13% free 24697K/28231K, paused 12ms+14ms
D/AudioHardware( 98): AudioHardware pcm playback is going to standby.
D/AudioHardware( 98): closePcmOut_l() mPcmOpenCnt: 1
I/ActivityManager( 199): Force stopping package com.myapp uid=10102
I/ActivityManager( 199): Killing proc 20698:com.myapp/10102: force stop
W/ActivityManager( 199): Force removing ActivityRecord{41eb1ec0 com.myapp/.Choice}: app died, no saved state
I/InputDispatcher( 199): Dropping event because there is no focused window or focused application.
I/ActivityManager( 199): Force finishing activity ActivityRecord{418450c8 com.myapp/.Activity}
I/InputDispatcher( 199): Dropping event because there is no focused window or focused application.
W/InputDispatcher( 199): channel '417b41f0 com.myapp/com.myapp/.Activity (server)' ~ Consumer closed input channel or an error occurred. events=0x8
E/InputDispatcher( 199): channel '417b41f0 com.myapp/com.myapp.Activity (server)' ~ Channel is unrecoverably broken and will be disposed!
W/InputDispatcher( 199): Attempted to unregister already unregistered input channel '417b41f0 com.myapp/com.myapp.Activity (server)'
W/WindowManager( 199): Failed looking up window
W/WindowManager( 199): java.lang.IllegalArgumentException: Requested window android.os.BinderProxy@41c7ffc8 does not exist
W/WindowManager( 199): at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7176)
W/WindowManager( 199): at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7167)
W/WindowManager( 199): at com.android.server.wm.WindowState$DeathRecipient.binderDied(WindowState.java:1545)
W/WindowManager( 199): at android.os.BinderProxy.sendDeathNotice(Binder.java:417)
W/WindowManager( 199): at dalvik.system.NativeStart.run(Native Method)
I/WindowManager( 199): WIN DEATH: null
I/WindowManager( 199): WIN DEATH: Window{4175b280 com.myapp/com.myapp.Choice paused=false}
W/WindowManager( 199): Failed looking up window
W/WindowManager( 199): java.lang.IllegalArgumentException: Requested window android.os.BinderProxy@41758028 does not exist
W/WindowManager( 199): at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7176)
W/WindowManager( 199): at com.android.server.wm.WindowManagerService.windowForClientLocked(WindowManagerService.java:7167)
W/WindowManager( 199): at com.android.server.wm.WindowState$DeathRecipient.binderDied(WindowState.java:1545)
W/WindowManager( 199): at android.os.BinderProxy.sendDeathNotice(Binder.java:417)
W/WindowManager( 199): at dalvik.system.NativeStart.run(Native Method)
I/WindowManager( 199): WIN DEATH: null
W/InputManagerService( 199): Got RemoteException sending setActive(false) notification to pid 20698 uid 10102
D/dalvikvm(20011): GC_CONCURRENT freed 460K, 32% free 9468K/13767K, paused 3ms+4ms
D/AudioHardware( 98): AudioHardware pcm playback is exiting standby.
D/AudioHardware( 98): openPcmOut_l() mPcmOpenCnt: 0
答案 0 :(得分：2)
我已经尝试过几次下载你的文件，看起来像是在这里和那里下载停顿几秒钟，它可能会在你的应用程序中触发超时。尝试在10-20秒范围内明确指定超时。
private DefaultHttpClient httpclient = new DefaultHttpClient();
private HttpGet get = new HttpGet("your url comes here");
protected String[] doInBackground(Void... v) {
HttpParams httpParameters = new BasicHttpParams();
// set the timeout in milliseconds until a connection is established
// the default value is zero, that means the timeout is not used
int timeoutConnection = 3000;
HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
// set the default socket timeout (SO_TIMEOUT) in milliseconds
// which is the timeout for waiting for data
int timeoutSocket = 5000;
HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
httpclient.setParams(httpParameters);
try {
HttpEntity entity = httpclient.execute( get ).getEntity();
FileOutputStream output = new FileOutputStream(outputFile);
entity.writeTo(output);
output.close();
// return something, maybe?
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
httpclient.getConnectionManager().shutdown();
}
return null;
}
答案 1 :(得分：1)
似乎问题是你的logcat中的进程199似乎是你的活动，但它显示：
I/ActivityManager( 199): Force stopping package com.viperean.atcassistant uid=10102
I/ActivityManager( 199): Killing proc 20698:com.viperean.atcassistant/10102: force stop
W/ActivityManager( 199): Force removing ActivityRecord{41eb1ec0 com.viperean.atcassistant/.atcChoice}: app died, no saved state
（第二行表明它正在杀死你的asynctask ...）。
我认为下载代码本身没有任何问题。我认为你应该更多地看一下这个活动（那个时候除了那个asynctask你在做什么，你在屏幕上显示什么......等等。）。
似乎你的堆空间也很低。
D/dalvikvm(20698): GC_CONCURRENT freed 103K, 3% free 9403K/9607K, paused 2ms+3ms
D/dalvikvm( 199): JIT code cache reset in 5 ms (1048440 bytes 13/0)
D/dalvikvm( 199): GC_CONCURRENT freed 1472K, 13% free 24697K/28231K, paused 12ms+14ms
那些来自垃圾收集并且在您的应用程序崩溃之前发生，也许这可能也是一个问题？
答案 2 :(得分：1)
onProgress并让线程保持活力