从广播接收器android调用AsyncTask [英] call AsyncTask from Broadcast receiver android
问题描述
所以目前我有一个AsyncTask类，当我单击一个按钮时，该类将运行并将POST的数据发送到我的服务器(效果很好).
SO currently i have an AsyncTask class that runs and POST's data to my server when I click a button(which works great).
我现在想做的是处理用户未连接到互联网时发生的情况.因此，我已经设置了这些类，以便在互联网已连接时通知应用程序，以便可以将数据自动发送到服务器.
What im trying to do now is handle what happens when the user is not connected to the internet. so i have set up these classes to notify the app when internet has connected so that the data can be sent automatically to the server.
AsyncTask类(内部类)
AsyncTask class(inner class)
private class HttpAsyncTask extends AsyncTask<String, Void, String> {
ProgressDialog dialog = new ProgressDialog(getActivity());
final AlertDialog finishedDialog = new AlertDialog.Builder(getActivity())
.setCancelable(false)
.setPositiveButton(android.R.string.ok, null)
.create();
@Override
protected String doInBackground(String... urls) {
onProgressUpdate("Uploading Data...");
return POST(urls[0]);
}
@Override
protected void onPreExecute() {
this.dialog.show();
finishedDialog.setOnShowListener(new DialogInterface.OnShowListener(){
@Override
public void onShow(DialogInterface dialog) {
Button b = finishedDialog.getButton(AlertDialog.BUTTON_POSITIVE);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// navigate to match summary.....
finishedDialog.dismiss();
}
});
}
});
}
protected void onProgressUpdate(String msg) {
dialog.setMessage(msg);
}
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
if (result != ""){
finishedDialog.setTitle("Upload Complete!");
finishedDialog.setMessage("Data Sent Successfully");
finishedDialog.show();
dialog.dismiss();
editor.clear();
editor.commit();
//Toast.makeText(getActivity().getBaseContext(), result, Toast.LENGTH_LONG).show();
}else
{
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
finishedDialog.setTitle("Upload Failed!");
finishedDialog.setMessage("Data Will Automatically Be Uploaded When Internet Connection Is Available");
finishedDialog.show();
dialog.dismiss();
}}, 1000);
setFlag(true);
}
}
}
public static boolean getFlag() {
return flag;
}
public void setFlag(boolean flag) {
this.flag = flag;
}
public String POST(String url){
InputStream inputStream = null;
String result = "";
try {
// 1. create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// 2. make POST request to the given URL
HttpPost httpPost = new HttpPost(url);
if(adapter.updateNeeded()){
JSONObject main = new JSONObject(exmaplePrefs.getString("jsonString", "cant find json"));
JSONObject dbUpdates = new JSONObject(exmaplePrefs.getString("ChangesJSON", "cant find Changejson"));
main.put("Team_Updates", dbUpdates);
json = main.toString();
}else{
json = exmaplePrefs.getString("jsonString", "cant find json");
// String json = "{\"twitter\":\"test\",\"country\":\"test\",\"name\":\"test\"}";
}
// 5. set json to StringEntity
StringEntity se = new StringEntity(json);
se.setContentType("application/json;charset=UTF-8");
// 6. set httpPost Entity
httpPost.setEntity(se);
// 7. Set some headers to inform server about the type of the content
// httpPost.setHeader("Accept", "application/json");
// httpPost.setHeader("Content-type", "application/json");
// httpPost.setHeader("json", json);
// 8. Execute POST request to the given URL
HttpResponse httpResponse = httpclient.execute(httpPost);
// 9. receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
String status = httpResponse.getStatusLine().toString();
// 10. convert inputstream to string
if (!status.equals("HTTP/1.1 500 Internal Server Error")){
if(inputStream != null){
result = convertInputStreamToString(inputStream);
}
else{
result = "Did not work!";
}
}else{
System.out.println("500 Error");
}
} catch (Exception e) {
Log.d("InputStream", e.getLocalizedMessage());
System.out.println("eerroorr "+e);
}
// 11. return result
System.out.println(result);
return result;
}
private static String convertInputStreamToString(InputStream inputStream) throws IOException{
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
}
NetworkUtil类
NetworkUtil class
public class NetworkUtil {
public static int TYPE_WIFI = 1;
public static int TYPE_MOBILE = 2;
public static int TYPE_NOT_CONNECTED = 0;
public static int getConnectivityStatus(Context context) {
ConnectivityManager cm = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
if (null != activeNetwork) {
if(activeNetwork.getType() == ConnectivityManager.TYPE_WIFI)
return TYPE_WIFI;
if(activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE)
return TYPE_MOBILE;
}
return TYPE_NOT_CONNECTED;
}
public static String getConnectivityStatusString(Context context) {
int conn = NetworkUtil.getConnectivityStatus(context);
String status = null;
if (conn == NetworkUtil.TYPE_WIFI) {
status = "Wifi enabled";
} else if (conn == NetworkUtil.TYPE_MOBILE) {
status = "Mobile data enabled";
} else if (conn == NetworkUtil.TYPE_NOT_CONNECTED) {
status = "Not connected to Internet";
}
return status;
}
}
BroadcastReceiver类
BroadcastReceiver class
public class NetworkChangeReceiver extends BroadcastReceiver {
@Override
public void onReceive(final Context context, final Intent intent) {
intent.getExtras();
String status = NetworkUtil.getConnectivityStatusString(context);
Toast.makeText(context, status, Toast.LENGTH_LONG).show();
if(MatchFragment.getFlag()){
//send data
}
}
}
因此，在BroadcastReceiver类中，当应用尝试发送数据但没有互联网时，我检查设置为true的标志(AsyncTask类中的onPostExecute).
So in the BroadcastReceiver class I check the flag that gets set to true when the app attempts to send data but there is not internet (onPostExecute in AsyncTask Class).
所以要做的是一些如何调用POST方法.我必须创建一个新的异步任务类吗?我在这里有些难过.
so what want to do is some how call the POST method. do i have to create a new Async task class? Im a bit stumped here .
谢谢
推荐答案
在BroadcastReceiver中使用AsyncTask是不好的做法.
您应该使用Service，因为Android操作系统可能会终止您的进程，或者onReceive()可能会在asyncTask返回结果之前运行完成，因此无法保证您将获得预期的结果.
You should use Service because Android OS may kill your process or onReceive() may run to completion before asyncTask will return result, so there is no guarantee you will get the expected result.
这篇关于从广播接收器android调用AsyncTask的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
