進行状況ダイアログを配置した作業中の非同期タスクがありました。問題は、進行状況ダイアログを入れるとクラッシュすることです:
public class CheckBeerJSON extends AsyncTask
<String, Void, String> {
Context c;
String b;
private ProgressDialog Dialog = new ProgressDialog(c);
public CheckBeerJSON(Context context, String beer)
{
c = context;
b = beer;
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
return readJSONFeed(arg0[0]);
}
protected void onPreExecute() {
Dialog.setMessage("Checking your portfolio");
Dialog.setTitle("Searching");
Dialog.show();
}
protected void onPostExecute(String result){
//decode json here
try{
JSONObject json = new JSONObject(result);
String status = json.getString("status");
if(status.equals("no")){
String message = "Beer not logged";
Toast.makeText(c, message, Toast.LENGTH_SHORT).show();
//clear loader image
LinearLayout ll = (LinearLayout) (LinearLayout)((Activity) c).findViewById(R.id.addBeerLayout);
ll.removeAllViews();
//Add beer add button
LayoutInflater mInflater = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout addButton = (LinearLayout)((Activity) c).findViewById(R.id.addBeerLayout);
addButton.addView(mInflater.inflate(R.layout.addbeerbutton_layout, null));
}
else{
String message = "You have the beer!!";
Toast.makeText(c, message, Toast.LENGTH_SHORT).show();
//clear loader image
LinearLayout ll = (LinearLayout) (LinearLayout)((Activity) c).findViewById(R.id.addBeerLayout);
ll.removeAllViews();
//inflate star rater
LayoutInflater mInflater = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout addButton = (LinearLayout)((Activity) c).findViewById(R.id.addBeerLayout);
addButton.addView(mInflater.inflate(R.layout.addrate_layout, null));
RatingBar r = (RatingBar) ((Activity) c).findViewById(R.id.beerRatingBar);
//get user data
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(c);
String userID = prefs.getString("userID", null);
//get beer rating with async task and update rate bar
String url = "my_other_url";
String userURLComp = "u=" + userID;
String beerID = "&b=" + b;
url = url + userURLComp + beerID;
new GetUserRating(c,r).execute(url);
//add listener to bar
addListenerOnRatingBar(c);
}
}
catch(Exception e){
}
Dialog.dismiss();
}
private void addListenerOnRatingBar(Context view) {
RatingBar ratingBar = (RatingBar) ((Activity) view).findViewById(R.id.beerRatingBar);
ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
public void onRatingChanged(RatingBar ratingBar, float rating,
boolean fromUser) {
//next async task to update online database
float stars = ratingBar.getRating();
//get user details
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(c);
String userID = prefs.getString("userID", null);
//get beer id
String beerID = b;
//get rating
String urlRate = "r=" + String.valueOf(ratingBar.getRating());
String urlUserID = "&u=" + userID;
String urlBeerID = "&b=" + beerID;
//construct url
String url2 = "my_url";
url2 = url2 + urlRate + urlUserID + urlBeerID;
Log.d("addRateing", url2);
//async task to update rating in database
new UpdateRating(c).execute(url2);
}
});
}
public String readJSONFeed(String URL) {
StringBuilder stringBuilder = new StringBuilder();
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(URL);
try {
HttpResponse response = httpClient.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream inputStream = entity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
inputStream.close();
} else {
Log.d("JSON", "Failed to download file");
}
} catch (Exception e) {
Log.d("readJSONFeed", e.getLocalizedMessage());
}
return stringBuilder.toString();
}
}
私が得るエラーは次のとおりです。
08-16 21:22:34.054 10772-10772/com.beerportfolio.beerportfoliopro E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.beerportfolio.beerportfoliopro/com.example.beerportfoliopro.BeerPage}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2332)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2368)
at android.app.ActivityThread.access$600(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1330)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:155)
at android.app.ActivityThread.main(ActivityThread.java:5536)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1074)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:841)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:142)
at android.app.AlertDialog.<init>(AlertDialog.java:98)
at android.app.ProgressDialog.<init>(ProgressDialog.java:77)
at com.example.beerportfoliopro.CheckBeerJSON.<init>(CheckBeerJSON.java:37)
at com.example.beerportfoliopro.BeerPage.onCreate(BeerPage.java:83)
at android.app.Activity.performCreate(Activity.java:5066)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2288)
... 11 more