java.lang.InstantiationException: java.lang.Class<com.wavedevelopers.eventsplanning.BookingForm> has no zero argument constructor

Question

I am trying to make a form using timepicker and datepicker but stuck on this error. I am just a beginner so please make it simple. I have created 2 inner classes DateDialogs and TimeDialogs.

Here is the java class.

 package com.wavedevelopers.eventsplanning; import android.app.DatePickerDialog; import android.app.Dialog; import android.app.TimePickerDialog; import android.content.Context; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v4.app.DialogFragment; import android.support.v4.app.FragmentActivity; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.text.format.DateFormat; import android.view.View; import android.widget.Button; import android.widget.DatePicker; import android.widget.EditText; import android.widget.TimePicker; import android.widget.Toast; import java.util.Calendar; public class BookingForm extends AppCompatActivity implements DatePickerDialog.OnDateSetListener,TimePickerDialog.OnTimeSetListener { BackgroundWorker backgroundWorker; Context ctx; public BookingForm(Context ctx) { this.ctx = ctx; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_booking_form); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) .setAction("Action", null).show(); } }); Button doneButton = (Button) findViewById(R.id.doneButton); Button datePickerButton = (Button) findViewById(R.id.datePickerButton); Button timePickerButton = (Button) findViewById(R.id.timePickerButton); final EditText name = (EditText) findViewById(R.id.userNameEditText); final EditText cnic = (EditText) findViewById(R.id.userCNICEditText); final EditText phone = (EditText) findViewById(R.id.userPhoneEditText); doneButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { backgroundWorker = new BackgroundWorker(ctx); backgroundWorker.doInBackground(name.getText().toString(),cnic.getText().toString(),phone.getText().toString()); backgroundWorker.execute(); } }); datePickerButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { DateDialogs pickerDialogs = new DateDialogs(); pickerDialogs.show(getSupportFragmentManager(),"date_picker"); } }); timePickerButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { TimeDialogs timeDialogs = new TimeDialogs(); timeDialogs.show(getSupportFragmentManager(),"time_picker"); } }); } @Override public void onDateSet(DatePicker datePicker, int year, int monthOfYear, int dayOfMonth) { Toast.makeText(this,"Selected Date: " + monthOfYear + " / " + dayOfMonth + " / " + year,Toast.LENGTH_LONG).show(); } @Override public void onTimeSet(TimePicker timePicker, int hourOfDay, int minute) { Toast.makeText(this,"Selected Time: " + hourOfDay + " : " + minute ,Toast.LENGTH_LONG).show(); } public static class DateDialogs extends DialogFragment { @Override public Dialog onCreateDialog(Bundle savedInstanceState) { BookingForm bookingForm = new BookingForm(getActivity()); Calendar calendar = Calendar.getInstance(); int year = calendar.get(Calendar.YEAR); int month = calendar.get(Calendar.MONTH); int day = calendar.get(Calendar.DAY_OF_MONTH); DatePickerDialog datePickerDialog; datePickerDialog = new DatePickerDialog(getActivity(), bookingForm,year,month,day); return datePickerDialog; } } public static class TimeDialogs extends DialogFragment { @Override public Dialog onCreateDialog(Bundle savedInstanceState) { BookingForm bookingForm = new BookingForm(getActivity()); Calendar calendar = Calendar.getInstance(); int hour = calendar.get(Calendar.HOUR_OF_DAY); int min = calendar.get(Calendar.MINUTE); TimePickerDialog timePickerDialog; timePickerDialog = new TimePickerDialog(getActivity(),bookingForm,hour,min, DateFormat.is24HourFormat(getActivity())); return timePickerDialog; } } }

And this is the error log.

 10-04 19:28:28.278 32605-32605/com.wavedevelopers.eventsplanning E/AndroidRuntime: FATAL EXCEPTION: main Process: com.wavedevelopers.eventsplanning, PID: 32605 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.wavedevelopers.eventsplanning/com.wavedevelopers.eventsplanning.BookingForm}: java.lang.InstantiationException: java.lang.Class<com.wavedevelopers.eventsplanning.BookingForm> has no zero argument constructor at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2337) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5443) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) Caused by: java.lang.InstantiationException: java.lang.Class<com.wavedevelopers.eventsplanning.BookingForm> has no zero argument constructor at java.lang.Class.newInstance(Native Method) at android.app.Instrumentation.newActivity(Instrumentation.java:1090) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5443) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 10-04 19:28:30.855 32605-32605/com.wavedevelopers.eventsplanning I/Process: Sending signal. PID: 32605 SIG: 9

Answer 1

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.wavedevelopers.eventsplanning/com.wavedevelopers.eventsplanning.BookingForm}: java.lang.InstantiationException: java.lang.Class<com.wavedevelopers.eventsplanning.BookingForm> has no zero argument constructor

This line tells me that the program expects you to make a constructor of your class BookingForm which takes no arguments.

You might want to add something like :

// Constructor with no arguments.
public BookingForm() {
    this.ctx = null;
}