java - App crashes when writing to SQLite Database in Android -

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• what nullpointerexception, , how fix it? 12 answers

i have developed app, user registration seems crash app. have checked cannot find cause, if can assist. code below.

java class

public class signup extends appcompatactivity {  databasehelper helper = new databasehelper(this);  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_sign_up);  }  public void onsignupclick (view view) {     if (view.getid() == r.id.bsignup)     {         edittext name = (edittext)findviewbyid(r.id.tfusername);         edittext email = (edittext)findviewbyid(r.id.tfemail);         edittext uname = (edittext)findviewbyid(r.id.tfuname);         edittext pass1 = (edittext)findviewbyid(r.id.tfpass1);         //edittext pass2 = (edittext)findviewbyid(r.id.tfpass2);          string namestr = name.gettext().tostring();         string emailstr = email.gettext().tostring();         string unamestr = uname.gettext().tostring();         string pass1str = pass1.gettext().tostring();          contact c = new contact();         c.setname(namestr);         c.setemail(emailstr);         c.setuname(unamestr);         c.setpass(pass1str);          helper.insertcontact(c);      }   } } 

xml layout

<linearlayout     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical">  <imageview     android:layout_width="match_parent"     android:src ="@drawable/saica"     android:layout_height="120dp" />      <textview         android:text="name"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/textview2" />      <edittext         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:inputtype="textpersonname"         android:text=""         android:ems="10"         android:id="@+id/tfname" />      <textview         android:text="email address"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/textview3" />      <edittext         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:inputtype="textpersonname"         android:text=""         android:ems="10"         android:id="@+id/tfemail" />      <textview         android:text="username"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/textview4" />      <edittext         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:inputtype="textpersonname"         android:text=""         android:ems="10"         android:id="@+id/tfuname" />      <textview         android:text="password"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/textview5" />      <edittext         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:inputtype="textpersonname"         android:text=""         android:ems="10"         android:id="@+id/tfpass1"         android:password="true" />      <button         android:text="register"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:id="@+id/bsignup"         android:onclick="onsignupclick"/>   </linearlayout> 

error log

fatal exception: main process: com.example.pooveshin.saica_sgb, pid: 10321 java.lang.illegalstateexception: not execute method android:onclick @ android.support.v7.app.appcompatviewinflater$declaredonclicklistener.onclick(appcompatviewinflater.java:293) @ android.view.view.performclick(view.java:4780) @ android.view.view$performclick.run(view.java:19866) @ android.os.handler.handlecallback(handler.java:739) @ android.os.handler.dispatchmessage(handler.java:95) @ android.os.looper.loop(looper.java:135) @ android.app.activitythread.main(activitythread.java:5254) @ java.lang.reflect.method.invoke(native method) @ java.lang.reflect.method.invoke(method.java:372) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903) @ com.android.internal.os.zygoteinit.main(zygoteinit.java:698) caused by: java.lang.nullpointerexception: attempt invoke virtual method 'android.text.editable android.widget.edittext.gettext()' on null object reference @ com.example.pooveshin.saica_sgb.signup.onsignupclick(signup.java:30) @ java.lang.reflect.method.invoke(native method) 

you don't have edittext named tfusername, actual edittext id tfname. should be

edittext name = (edittext)findviewbyid(r.id.tfname);