我的应用程序调用4个不同的asynchtask。很多时候应用程序按预期工作，但有时它会与asynchtask中的错误一起崩溃。
这是我的logcat
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: java.io.IOException: Attempted read on closed stream.
10-05 10:57:30.282 27705-27785/com.malav.holistree E/JSON Parser: Error parsing data org.json.JSONException: End of input at character 0 of
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at org.apache.http.conn.EofSensorInputStream.isReadAllowed(EofSensorInputStream.java:132)
10-05 10:57:30.282 27705-27785/com.malav.holistree W/System.err: at org.json.JSONException: End of input at character 0 of
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:162)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at java.io.InputStreamReader.read(InputStreamReader.java:233)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at java.io.BufferedReader.fillBuf(BufferedReader.java:145)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at java.io.BufferedReader.readLine(BufferedReader.java:397)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at com.malav.holistree.util.JSONfunctions.makeHttpRequest(JSONfunctions.java:126)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:492)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:476)
10-05 10:57:30.282 27705-27785/com.malav.holistree W/System.err: at org.json.JSONTokener.syntaxError(JSONTokener.java:449)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:295)
10-05 10:57:30.282 27705-27785/com.malav.holistree W/System.err: at org.json.JSONTokener.nextValue(JSONTokener.java:97)
10-05 10:57:30.282 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
10-05 10:57:30.282 27705-27785/com.malav.holistree W/System.err: at org.json.JSONObject.<init>(JSONObject.java:156)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at org.json.JSONObject.<init>(JSONObject.java:173)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at com.malav.holistree.util.JSONfunctions.makeHttpRequest(JSONfunctions.java:141)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at com.malav.holistree.notification.RegistrationIntentService.onHandleIntent(RegistrationIntentService.java:79)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at android.app.IntentService$ServiceHandler.handleMessage(IntentService.java:66)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at android.os.Looper.loop(Looper.java:148)
10-05 10:57:30.283 27705-27785/com.malav.holistree W/System.err: at android.os.HandlerThread.run(HandlerThread.java:61)
10-05 10:57:30.283 27705-27781/com.malav.holistree W/System.err: android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
10-05 10:57:30.283 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.lang.Thread.run(Thread.java:818)
10-05 10:57:30.284 27705-27781/com.malav.holistree E/JSON Parser: Error parsing data org.json.JSONException: End of input at character 0 of
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: org.json.JSONException: End of input at character 0 of
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at org.json.JSONTokener.syntaxError(JSONTokener.java:449)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at org.json.JSONTokener.nextValue(JSONTokener.java:97)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at org.json.JSONObject.<init>(JSONObject.java:156)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at org.json.JSONObject.<init>(JSONObject.java:173)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at com.malav.holistree.util.JSONfunctions.makeHttpRequest(JSONfunctions.java:141)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:492)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:476)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:295)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
10-05 10:57:30.284 27705-27781/com.malav.holistree W/System.err: at java.lang.Thread.run(Thread.java:818)
10-05 10:57:30.287 27705-27781/com.malav.holistree E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.malav.holistree, PID: 27705
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'org.json.JSONArray org.json.JSONObject.getJSONArray(java.lang.String)' on a null object reference
at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:495)
at com.malav.holistree.dashboard.DashboardFragment$fetchQuote.doInBackground(DashboardFragment.java:476)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
10-05 10:57:30.312 27705-27720/com.malav.holistree V/FA: Activity paused, time: 171909023
10-05 10:57:30.629 27705-27720/com.malav.holistree D/FA: Application backgrounded. Logging engagement
10-05 10:57:30.632 27705-27720/com.malav.holistree I/FA: Tag Manager is not found and thus will not be used
10-05 10:57:30.635 27705-27720/com.malav.holistree D/FA: Logging event (FE): _e, Bundle[{_o=auto, _et=3710}]
10-05 10:57:30.693 27705-27705/com.malav.holistree D/FirebaseApp: Notifying background state change listeners.
10-05 10:57:31.312 27705-27720/com.malav.holistree D/FA: Application backgrounded. Logging engagement
10-05 10:57:31.312 27705-27720/com.malav.holistree W/FA: Not logging non-positive engagement time: 0
这是我的Java代码
public class DashboardFragment extends Fragment {
List<SpinnerWithTag> studentList;
private Activity activity;
public Context context;
public static String filename = "MySharedString";
private SharedPreferences someData;
private ListView reminderList, upcomingMeetingList;
private EditText question;
private String s_question,l_Id;
private Button post;
private TextView hasNoMeetings,textViewTodayQuote;
ImageButton editQuote;
String todayQuote;
Spinner studentSpinner;
String selectedStudent, selectedStudentL_Id;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
activity = getActivity();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.dashboard_fragment, container, false);
someData = activity.getSharedPreferences(filename, 0);
reminderList = (ListView) view.findViewById(R.id.listReminder);
upcomingMeetingList = (ListView) view.findViewById(R.id.listMeetings);
post = (Button) view.findViewById(R.id.post);
question = (EditText) view.findViewById(R.id.question);
hasNoMeetings = (TextView) view.findViewById(R.id.textNoMeetings);
editQuote = (ImageButton) view.findViewById(R.id.editQuote);
textViewTodayQuote = (TextView) view.findViewById(R.id.todayQuote);
studentSpinner = (Spinner) view.findViewById(R.id.studentsSpinner);
l_Id = someData.getString("commonL_Id", "");
if(Utility.isOnline(activity)){
new fetchQuote().execute();
}
post.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(CommonUtils.isNotNull(question.getText().toString())){
s_question = question.getText().toString();
if(Utility.isOnline(activity)){
new PostQuestion().execute();
}
}else{
Toast.makeText(activity, "Cannot post blank question", Toast.LENGTH_LONG).show();
}
}
});
editQuote.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new MaterialDialog.Builder(activity)
.title("Update Quote")
.inputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_FLAG_MULTI_LINE)
.positiveText("Update")
.input("Type here", "", false, new MaterialDialog.InputCallback() {
@Override
public void onInput(@NonNull MaterialDialog dialog, CharSequence input) {
//showToast("Hello, " + input.toString() + "!");
todayQuote = input.toString();
new AddQuote().execute();
}
}).show();
}
});
studentSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
SpinnerWithTag s = (SpinnerWithTag) parent.getItemAtPosition(position);
selectedStudent = s.getString();
selectedStudentL_Id = s.getTag();
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
return view;
}
class GrabAllStudents extends AsyncTask<String, String, String> {
JSONArray jsonarray;
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... params) {
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("role", "Students"));
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_ALL_STUDENTS, "POST", para);
try{
studentList = new ArrayList<SpinnerWithTag>();
studentList.clear();
studentList.add(new SpinnerWithTag("Select Student", "0"));
studentList.add(new SpinnerWithTag("Select Global", "-1"));
jsonarray = jsonobject.getJSONArray("All_Students");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
String studentName = jsonobject.getString("name");
String selectedStudentL_Id = jsonobject.getString("l_Id");
studentList.add(new SpinnerWithTag(studentName,selectedStudentL_Id));
}
} catch (JSONException e) {
e.printStackTrace();
}
return "Success";
}
@Override
protected void onPostExecute(String sResponse) {
new GrabAllAdminUpcomingMeetings().execute();
ArrayAdapter<SpinnerWithTag> adapter = new ArrayAdapter<SpinnerWithTag> (activity, R.layout.spinner_item_result, studentList);
studentSpinner.setAdapter(adapter);
}
}
class GrabAllUpcomingMeetings extends AsyncTask<String, String, String> {
int flag = 0;
JSONArray jsonarray;
ArrayList<HashMap<String,String>> myAppointmentList;
MyAppointmentDashboardAdapter myAppointmentAdapter;
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("booked_l_Id", l_Id));
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_MY_APPOINTMENT, "POST", para);
try{
myAppointmentList = new ArrayList<HashMap<String,String>>();
jsonarray = jsonobject.getJSONArray("My_Appointments");
for (int i = 0; i < jsonarray.length(); i++)
{
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
map.put("startTime", jsonobject.getString("startTime"));
map.put("endTime", jsonobject.getString("endTime"));
map.put("appt_Id", jsonobject.getString("appt_Id"));
map.put("l_Id", jsonobject.getString("l_Id"));
map.put("m_Id", jsonobject.getString("m_Id"));
map.put("date", jsonobject.getString("date"));
map.put("booked", jsonobject.getString("booked"));
map.put("approved", jsonobject.getString("approved"));
map.put("booked_l_Id", jsonobject.getString("booked_l_Id"));
map.put("booked_date", jsonobject.getString("booked_date"));
map.put("color", Integer.toString(Utility.getRandomColor(activity)));
myAppointmentList.add(map);
}
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
myAppointmentAdapter = new MyAppointmentDashboardAdapter(activity, myAppointmentList);
upcomingMeetingList.setAdapter(myAppointmentAdapter);
}
}
class GrabAllAdminUpcomingMeetings extends AsyncTask<String, String, String> {
int flag = 0;
JSONArray jsonarray;
ArrayList<HashMap<String,String>> adminAllAppointmentList;
AdminBookedAppointmentDashboardAdapter AdminAppointmentAdapter;
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_BOOKED_APPOINTMENT_LIST_ADMIN_FRAGMENT, "POST", para);
try{
adminAllAppointmentList = new ArrayList<HashMap<String,String>>();
jsonarray = jsonobject.getJSONArray("Admin_Appointment_List");
for (int i = 0; i < jsonarray.length(); i++)
{
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
map.put("startTime", jsonobject.getString("startTime"));
map.put("endTime", jsonobject.getString("endTime"));
map.put("appt_Id", jsonobject.getString("appt_Id"));
map.put("l_Id", jsonobject.getString("l_Id"));
map.put("m_Id", jsonobject.getString("m_Id"));
map.put("date", jsonobject.getString("date"));
map.put("booked", jsonobject.getString("booked"));
map.put("approved", jsonobject.getString("approved"));
map.put("booked_l_Id", jsonobject.getString("booked_l_Id"));
map.put("booked_date", jsonobject.getString("booked_date"));
map.put("name", jsonobject.getString("name"));
map.put("phone", jsonobject.getString("phone"));
map.put("emailId", jsonobject.getString("emailId"));
}
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url)
{
if(adminAllAppointmentList!=null && adminAllAppointmentList.size()>0){
hasNoMeetings.setVisibility(View.GONE);
}
AdminAppointmentAdapter = new AdminBookedAppointmentDashboardAdapter(activity, adminAllAppointmentList);
upcomingMeetingList.setAdapter(AdminAppointmentAdapter);
}
}
class GrabAllReminders extends AsyncTask<String, String, String> {
int flag = 0;
JSONArray jsonarray;
ArrayList<HashMap<String,String>> myRemindersList;
ReminderAdapter reminderAdapter;
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("login_Id", l_Id));
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_GRAB_ALL_REMINDERS, "POST", para);
try{
myRemindersList = new ArrayList<HashMap<String,String>>();
jsonarray = jsonobject.getJSONArray("All_Reminders");
for (int i = 0; i < jsonarray.length(); i++)
{
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
map.put("r_date", jsonobject.getString("r_date"));
map.put("reminder", jsonobject.getString("reminder"));
map.put("r_Id", jsonobject.getString("r_Id"));
map.put("login_Id", jsonobject.getString("login_Id"));
myRemindersList.add(map);
}
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
reminderAdapter = new ReminderAdapter(activity, myRemindersList);
reminderList.setAdapter(reminderAdapter);
}
}
class PostQuestion extends AsyncTask<String, String, String> {
int flag = 0;
String success="0", message="";
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("l_Id", l_Id));
para.add(new BasicNameValuePair("question", s_question));
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_POST_QUESTION, "POST", para);
try{
success = jsonobject.getString("success");
message = jsonobject.getString("message");
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
if(!success.equalsIgnoreCase("0") && !success.equalsIgnoreCase("")){
question.setText("");
Toast.makeText(activity, "Question posted successfully", Toast.LENGTH_LONG).show();
}else{
}
}
}
class AddQuote extends AsyncTask<String, String, String> {
int flag = 0;
String success="0", message="";
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("todayQuote", todayQuote));
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_ADD_QUOTE, "POST", para);
try{
success = jsonobject.getString("success");
message = jsonobject.getString("message");
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
if(!success.equalsIgnoreCase("0") && !success.equalsIgnoreCase("")){
textViewTodayQuote.setText(todayQuote);
Toast.makeText(activity, "Quote Updates", Toast.LENGTH_LONG).show();
}else{
Toast.makeText(activity, "Quote failed to post", Toast.LENGTH_LONG).show();
}
}
}
class fetchQuote extends AsyncTask<String, String, String> {
int flag = 0;
JSONArray jsonarray;
String success="0", message="";
String quote;
protected void onPreExecute()
{
super.onPreExecute();
}
protected String doInBackground(String... params)
{
List<NameValuePair> para = new ArrayList<NameValuePair>();
para.add(new BasicNameValuePair("todayQuote", todayQuote));
Log.d("request!", "starting");
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_FETCH_QUOTE, "POST", para);
try{
jsonarray = jsonobject.getJSONArray("TodaysQuote");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
quote = jsonobject.getString("quoteText");
}
}catch(JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
textViewTodayQuote.setText(quote);
if(someData.contains("role")) {
if (Utility.isOnline(activity)) {
new GrabAllReminders().execute();
if (someData.getString("role", "").equalsIgnoreCase("Admin")) {
editQuote.setVisibility(View.VISIBLE);
studentSpinner.setVisibility(View.VISIBLE);
new GrabAllStudents().execute();
}else{
new GrabAllUpcomingMeetings().execute();
}
}else{
Toast.makeText(getActivity(), "Connectivity Issues, You are offline", Toast.LENGTH_LONG).show();
}
}
}
}
}
我的PHP文件正在以预期的方式正确返回数据。
我很困惑，应用程序不是每次都崩溃。它偶尔会崩溃。
答案 0 :(得分：2)
将此行放在try/catch。
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_MY_APPOINTMENT, "POST", para);
答案 1 :(得分：2)
logcat日志显示问题所在：
at com.malav.holistree.util.JSONfunctions.makeHttpRequest(JSONfunctions.java:126)
所以它在JSONfunctions.java和第126行。
有java.io.IOException: Attempted read on closed stream.因此您可能偶尔遇到网络或服务器问题，当您尝试从数据构建org.json.JSONException时，还会JSONObject那不是。
如果您希望有人查看它，您可以发布JSONfunctions.java，并建议改进错误处理。
您可以打包方法调用
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_ALL_STUDENTS, "POST", para);
在try catch中，应该抓住 java.io.IOException和org.json.JSONException。
但是当然你要么在try-catch之外需要JSONObject jsonobject;，要么你也可以在同一个try-catch中包含访问jsonobject的所有代码：
try {
JSONObject jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_ALL_STUDENTS, "POST", para);
studentList = new ArrayList<SpinnerWithTag>();
studentList.clear();
studentList.add(new SpinnerWithTag("Select Student", "0"));
studentList.add(new SpinnerWithTag("Select Global", "-1"));
jsonarray = jsonobject.getJSONArray("All_Students");
for (int i = 0; i < jsonarray.length(); i++) {
jsonobject = jsonarray.getJSONObject(i);
String studentName = jsonobject.getString("name");
String selectedStudentL_Id = jsonobject.getString("l_Id");
studentList.add(new SpinnerWithTag(studentName,selectedStudentL_Id));
}
} catch (JSONException|java.io.IOException e) {
e.printStackTrace();
}
或者你可以只包括麻烦的方法调用，并在catch块中返回除了＆＃34;成功＆＃34;：
之外的其他内容JSONObject jsonobject;
try {
jsonobject = JSONfunctions.makeHttpRequest(QueryMapper.URL_ALL_STUDENTS, "POST", para);
} catch (JSONException|java.io.IOException e) {
e.printStackTrace();
return "";
}
现在studentList会有一些旧数据（可能......我不详细了解您的应用程序）如果onPostExecute()您应忽略doInBackground()中的代码返回＆＃34;成功＆＃34;：
@Override
protected void onPostExecute(String sResponse) {
if (sResponse.equals("Success") {
new GrabAllAdminUpcomingMeetings().execute();
ArrayAdapter<SpinnerWithTag> adapter = new ArrayAdapter<SpinnerWithTag> (activity, R.layout.spinner_item_result, studentList);
studentSpinner.setAdapter(adapter);
}
}
如您更了解代码，您应该考虑在这种情况下studentSpinner.setAdapter(adapter);方法调用是否存在任何问题。
简单地用try-catch包装JSONfunctions.makeHttpRequest()方法调用无论如何都会留下一些问题。
答案 2 :(得分：0)
您的数据请求不正确。输入流正在关闭，因为：
require 'FastRoute/RouteCollector.php';
require 'FastRoute/Dispatcher.php';
...
这意味着您的服务器偶尔会返回一个对象的空值。检查您的PHP并验证返回的数据。具体来说，您可能希望逐行解析而不是依赖库来调试这个。