我在OnCreate（）中执行了3个异步调用我正在执行所有3个获取数据并更新列表视图。这在移动网络上完美运行但在Wifi上它不能正常工作。此外，我猜它正在发生并行。
请让我知道为什么它在wifi上不能完美运行。如果这对于一次执行3个异步调用是完美的，请告诉我。我非常感谢任何帮助。谢谢你。
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mContext = this;
setContentView(R.layout.activity_main);
listview1 = new ListView(mContext);
listview2 = new ListView(mContext);
listview3 = new ListView(mContext);
////
arraylist1 = new ArrayList<HashMap<String, String>>();
new LoadInbox1().execute();
arraylist2 = new ArrayList<HashMap<String, String>>();
new LoadInbox2().execute();
arraylist3 = new ArrayList<HashMap<String, String>>();
new LoadInbox3().execute();
}
class LoadInbox1 extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Loading Inbox ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting Inbox JSON
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jsonParser.makeHttpRequest(INBOX_URL, "GET",
params);
// Check your log cat for JSON reponse
Log.d("Inbox JSON: ", json.toString());
try {
inbox = json.getJSONArray(TAG_MESSAGES);
// looping through All messages
for (int i = 0; i < inbox.length(); i++) {
JSONObject c = inbox.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String from = c.getString(TAG_FROM);
String subject = c.getString(TAG_SUBJECT);
String date = c.getString(TAG_DATE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_FROM, from);
map.put(TAG_SUBJECT, subject);
map.put(TAG_DATE, date);
// adding HashList to ArrayList
arraylist1.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
listview1.setAdapter(new SimpleAdapter(
MainActivity.this, arraylist1,
R.layout.inbox_list_item, new String[] { TAG_FROM, TAG_SUBJECT, TAG_DATE },
new int[] { R.id.from, R.id.subject, R.id.date }));
}
});
}
}
class LoadInbox2 extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Loading Inbox ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting Inbox JSON
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jsonParser.makeHttpRequest(INBOX_URL, "GET",
params);
// Check your log cat for JSON reponse
Log.d("Inbox JSON: ", json.toString());
try {
inbox = json.getJSONArray(TAG_MESSAGES);
// looping through All messages
for (int i = 0; i < inbox.length(); i++) {
JSONObject c = inbox.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String from = c.getString(TAG_FROM);
String subject = c.getString(TAG_SUBJECT);
String date = c.getString(TAG_DATE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_FROM, from);
map.put(TAG_SUBJECT, subject);
map.put(TAG_DATE, date);
// adding HashList to ArrayList
arraylist2.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
listview2.setAdapter(new SimpleAdapter(
MainActivity.this, arraylist2,
R.layout.inbox_list_item, new String[] { TAG_FROM, TAG_SUBJECT, TAG_DATE },
new int[] { R.id.from, R.id.subject, R.id.date }));
}
});
}
}
class LoadInbox3 extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Loading Inbox ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting Inbox JSON
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jsonParser.makeHttpRequest(INBOX_URL, "GET",
params);
// Check your log cat for JSON reponse
Log.d("Inbox JSON: ", json.toString());
try {
inbox = json.getJSONArray(TAG_MESSAGES);
// looping through All messages
for (int i = 0; i < inbox.length(); i++) {
JSONObject c = inbox.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String from = c.getString(TAG_FROM);
String subject = c.getString(TAG_SUBJECT);
String date = c.getString(TAG_DATE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_FROM, from);
map.put(TAG_SUBJECT, subject);
map.put(TAG_DATE, date);
// adding HashList to ArrayList
arraylist3.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
listview3.setAdapter(new SimpleAdapter(
MainActivity.this, arraylist3,
R.layout.inbox_list_item, new String[] { TAG_FROM, TAG_SUBJECT, TAG_DATE },
new int[] { R.id.from, R.id.subject, R.id.date }));
}
});
}
}
logcat的
02-19 01:54:46.574: W/System.err(32377): java.net.SocketException: recvfrom failed: ETIMEDOUT (Connection timed out)
02-19 01:54:46.584: W/System.err(32377): at libcore.io.IoBridge.maybeThrowAfterRecvfrom(IoBridge.java:545)
02-19 01:54:46.584: W/System.err(32377): at libcore.io.IoBridge.recvfrom(IoBridge.java:509)
02-19 01:54:46.584: W/System.err(32377): at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
02-19 01:54:46.584: W/System.err(32377): at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:46)
02-19 01:54:46.584: W/System.err(32377): at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:240)
02-19 01:54:46.584: W/System.err(32377): at org.apache.http.impl.io.AbstractSessionInputBuffer.fillBuffer(AbstractSessionInputBuffer.java:103)
02-19 01:54:46.584: W/System.err(32377): at org.apache.http.impl.io.AbstractSessionInputBuffer.read(AbstractSessionInputBuffer.java:134)
02-19 01:54:46.584: W/System.err(32377): at org.apache.http.impl.io.ChunkedInputStream.read(ChunkedInputStream.java:161)
02-19 01:54:46.594: W/System.err(32377): at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:159)
02-19 01:54:46.594: W/System.err(32377): at java.io.InputStreamReader.read(InputStreamReader.java:233)
02-19 01:54:46.594: W/System.err(32377): at java.io.BufferedReader.fillBuf(BufferedReader.java:145)
02-19 01:54:46.594: W/System.err(32377): at java.io.BufferedReader.readLine(BufferedReader.java:397)
02-19 01:54:46.594: W/System.err(32377): at com.example.example.MainActivity$list3.doInBackground(MainActivity.java:776)
02-19 01:54:46.594: W/System.err(32377): at com.example.example.MainActivity$list3.doInBackground(MainActivity.java:1)
02-19 01:54:46.594: W/System.err(32377): at android.os.AsyncTask$2.call(AsyncTask.java:288)
02-19 01:54:46.604: W/System.err(32377): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
02-19 01:54:46.604: W/System.err(32377): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
02-19 01:54:46.604: W/System.err(32377): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
02-19 01:54:46.604: W/System.err(32377): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
02-19 01:54:46.604: W/System.err(32377): at java.lang.Thread.run(Thread.java:841)
02-19 01:54:46.604: W/System.err(32377): Caused by: libcore.io.ErrnoException: recvfrom failed: ETIMEDOUT (Connection timed out)
02-19 01:54:46.614: W/System.err(32377): at libcore.io.Posix.recvfromBytes(Native Method)
02-19 01:54:46.614: W/System.err(32377): at libcore.io.Posix.recvfrom(Posix.java:141)
02-19 01:54:46.614: W/System.err(32377): at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:164)
02-19 01:54:46.614: W/System.err(32377): at libcore.io.IoBridge.recvfrom(IoBridge.java:506)
答案 0 :(得分：0)
从LogCat我看到你的连接超时，所以你不应该期待列表中的任何数据。相反，您应该处理此错误情况以通知用户存在错误。