android button causing crash

Question

I am trying to pass login details to another class so that it can be used to login on my MySQL db (using php) but it is crashing giving me the exception: java.lang.IllegalStateException: Could not execute method for android:onClick

stack trace: {StackTraceElement[0]@5692}

658 10752-10752/uk.ac.abertay.contactslist E/AndroidRuntime: FATAL EXCEPTION: main Process: uk.ac.abertay.contactslist, PID: 10752 java.lang.IllegalStateException: Could not execute method for android:onClick at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293) at android.view.View.performClick(View.java:6294) at android.view.View$PerformClick.run(View.java:24770) at android.os.Handler.handleCallback(Handler.java:790) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:6294) at android.view.View$PerformClick.run(View.java:24770) at android.os.Handler.handleCallback(Handler.java:790) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void uk.ac.abertay.contactslist.Login.Logino(uk.ac.abertay.contactslist.LoginDetails)' on a null object reference at uk.ac.abertay.contactslist.LoginActivity.Loginbutton(LoginActivity.java:40) at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:6294) at android.view.View$PerformClick.run(View.java:24770) at android.os.Handler.handleCallback(Handler.java:790) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807) 04-26 15:39:34.761 1384-3633/? I/chatty: uid=1041(audioserver) writer identical 8 lines

this is the code for the button

    private Login login;


   public void Loginbutton(View v) {

    /* Get entered fields data. */
    String email = field_email.getText().toString();
    String password = field_password.getText().toString();


         login.Logino(new LoginDetails(email,password));



    }

when debugging it will run this and go back to the button and after that it will give the exception and crash

public class LoginDetails {

   public String email = "";
   public String password = "";

   LoginDetails(String e, String p) {
       email = e;
       password = p;
   }
}

this is the code I'm trying to run with the button above

public void Logino(LoginDetails loginDetails) {
    LoginTask task = new LoginTask();
    task.execute(loginDetails);
}

That doesn't help, copy the stacktrace printed in the logcat — Marcos Vasconcelos, Apr 26 '18 at 19:35
@MarcosVasconcelos sorry i never showed it but i did declare it, put in on now — the pro-gramer, Apr 26 '18 at 20:08
@MarcosVasconcelos actually i got it, thanks for the help ill add an answer — the pro-gramer, Apr 26 '18 at 20:15

score 0 · Answer 1 · answered Apr 26 '18 at 19:46

0

From your StackTrace

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void uk.ac.abertay.contactslist.Login.Logino(uk.ac.abertay.contactslist.LoginDetails)

The line login.Logino the object login is null, you have to initialize it.

Obs:Please use Java naming conventions with method names starting with low case char.

answered Apr 26 '18 at 19:46

Marcos Vasconcelos

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Please don't post answers on questions that you vote to close. Closing means no answers can be posted, so that's basically you trying to prevent others from answering after you have. – Mike M. Apr 26 '18 at 20:19
Haaa.. good point Mike, next time only comments – Marcos Vasconcelos Apr 26 '18 at 20:40

android button causing crash

1 Answers1