我不断收到即使我把它扔进的AsyncTask的doInBackground方法一CalledFromWrongThreadException!谁能告诉我,为什么,以及如何解决它?
/ ** *确认在responseTexts关键词并运行相应的功能 * @参数的responseText * / 私人无效ResponseHandler所(字符串的responseText){ 如果(responseText.startsWith(注意事项,0)){ notes.add(responseText的); 新DownloadFilesTask()执行(WriteInternal,NULL,NULL); } }
这是我的AsyncTask类
私有类DownloadFilesTask扩展的AsyncTask<弦乐,太虚,字符串> { 保护字符串doInBackground(字符串...命令){ 如果(指令[0] .equals(WriteInternal){ //写内部存储 FileOutputStream中FOUT = NULL; OutputStreamWriter OSW = NULL; 尝试{ FOUT = openFileOutput(notes.txt,Context.MODE_PRIVATE); OSW =新OutputStreamWriter(FOUT); 的for(int i = 0; I< notes.size();我++){ osw.write(notes.get(ⅰ)+\\ n); } osw.close(); fOut.close(); }赶上(例外五){ e.printStackTrace(System.err的); } notesListView.setAdapter(arrayAdapter); //刷新列表视图 }其他{ sendCommand(命令[0]); 返回null;} } 保护无效onProgressUpdate(无效...进度){} 保护无效onPostExecute(字符串结果){}}
下面是我得到的堆栈跟踪:
05-22 15:14:20.370:E / AndroidRuntime(11730):致命异常:AsyncTask的#205-22 15:14:20.370:E / AndroidRuntime(11730):了java.lang.RuntimeException:执行doInBackground发生错误()05-22 15:14:20.370:E / AndroidRuntime(11730):在android.os.AsyncTask $ 3.done(AsyncTask.java:278)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.FutureTask中$ Sync.innerSetException(FutureTask.java:273)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.FutureTask.setException(FutureTask.java:124)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.FutureTask中$ Sync.innerRun(FutureTask.java:307)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.FutureTask.run(FutureTask.java:137)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.os.AsyncTask $ SerialExecutor $ 1.run(AsyncTask.java:208)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.ThreadPoolExecutor中的$ Worker.run(ThreadPoolExecutor.java:569)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.lang.Thread.run(Thread.java:856)05-22 15:14:20.370:E / AndroidRuntime(11730):$ android.view.ViewRootImpl CalledFromWrongThreadException:只有创建视图层次可以触摸其观点原来的线程所致。05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4039)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.ViewRootImpl.invalidateChild(ViewRootImpl.java:722)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:771)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.ViewGroup.invalidateChild(ViewGroup.java:4005)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.View.invalidate(View.java:8576)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.view.View.invalidate(View.java:8527)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.widget.AbsListView.resetList(AbsListView.java:1734)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.widget.ListView.resetList(ListView.java:502)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.widget.ListView.setAdapter(ListView.java:442)05-22 15:14:20.370:E / AndroidRuntime(11730):在com.nelson.jarvisclientics.Notes $ DownloadFilesTask.doInBackground(Notes.java:281)05-22 15:14:20.370:E / AndroidRuntime(11730):在com.nelson.jarvisclientics.Notes $ DownloadFilesTask.doInBackground(Notes.java:1)05-22 15:14:20.370:E / AndroidRuntime(11730):在android.os.AsyncTask $ 2.call(AsyncTask.java:264)05-22 15:14:20.370:E / AndroidRuntime(11730):在java.util.concurrent.FutureTask中$ Sync.innerRun(FutureTask.java:305)05-22 15:14:20.370:E / AndroidRuntime(11730):... 5个
解决方案
试着用 runOnUIThread包装您的文件访问code(新的Runnable {/ * code到这里* /}( ))
I keep getting a CalledFromWrongThreadException even if i throw it into AsyncTask's DoInBackground method! Can anyone tell me why and how to fix it?
/**
* Recognizes key words in responseTexts and runs the appropriate function
* @param responseText
*/
private void responseHandler(String responseText) {
if(responseText.startsWith("Notes", 0)) {
notes.add(responseText);
new DownloadFilesTask().execute("WriteInternal" , null, null);
}
}
this is my AsyncTask class
private class DownloadFilesTask extends AsyncTask<String, Void, String> {
protected String doInBackground(String... command) {
if(command[0].equals("WriteInternal") {
//write to internal storage
FileOutputStream fOut = null;
OutputStreamWriter osw = null;
try{
fOut = openFileOutput("notes.txt", Context.MODE_PRIVATE);
osw = new OutputStreamWriter(fOut);
for (int i = 0; i < notes.size(); i++){
osw.write(notes.get(i) + "\n");
}
osw.close();
fOut.close();
} catch(Exception e) {
e.printStackTrace(System.err);
}
notesListView.setAdapter(arrayAdapter); //refreshes the listView
}
else {
sendCommand(command[0]);
return null;
}
}
protected void onProgressUpdate(Void... progress) {}
protected void onPostExecute(String result) {}
}
Here's the stacktrace I got:
05-22 15:14:20.370: E/AndroidRuntime(11730): FATAL EXCEPTION: AsyncTask #2
05-22 15:14:20.370: E/AndroidRuntime(11730): java.lang.RuntimeException: An error occured while executing doInBackground()
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.os.AsyncTask$3.done(AsyncTask.java:278)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.lang.Thread.run(Thread.java:856)
05-22 15:14:20.370: E/AndroidRuntime(11730): Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4039)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.ViewRootImpl.invalidateChild(ViewRootImpl.java:722)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:771)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.ViewGroup.invalidateChild(ViewGroup.java:4005)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.View.invalidate(View.java:8576)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.view.View.invalidate(View.java:8527)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.widget.AbsListView.resetList(AbsListView.java:1734)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.widget.ListView.resetList(ListView.java:502)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.widget.ListView.setAdapter(ListView.java:442)
05-22 15:14:20.370: E/AndroidRuntime(11730): at com.nelson.jarvisclientics.Notes$DownloadFilesTask.doInBackground(Notes.java:281)
05-22 15:14:20.370: E/AndroidRuntime(11730): at com.nelson.jarvisclientics.Notes$DownloadFilesTask.doInBackground(Notes.java:1)
05-22 15:14:20.370: E/AndroidRuntime(11730): at android.os.AsyncTask$2.call(AsyncTask.java:264)
05-22 15:14:20.370: E/AndroidRuntime(11730): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
05-22 15:14:20.370: E/AndroidRuntime(11730): ... 5 more
解决方案
Try wrapping your file access code with runOnUIThread(new Runnable{/*code goes here*/}())