Android Studio New Activity Causes Crash

Question

Further adventures into Android Studio!

I did have this working. I have a log in activity when then passes to another one. Quite simple at the moment. Worked perfectly on the emulator. Tried it with my phone attached and it threw a NetworkOnMainException... So, researched that and put the internet log in check into a separate Async thread.

When I execute my app now, when it starts the new activity, it crashes. The odd thing is, if I debug this and step through the code, it works and the second activity is displayed. If I let the app run at it's own speed, it crashes.

My log in button method is:

public void signInButtonClick(View v) throws InterruptedException {

       // Button button=(Button) v;

        String loginSql;

        Globals.userName =   loginID.getText().toString();

        Globals.passWord = loginPW.getText().toString();
        //www.myarraydata.com/app/androidlogin.php?username=X&password=Y
        loginSql = "http://www.mywebsite.com/app/loginscript.php?username="+Globals.userName+"&password="+Globals.passWord ;
        ((Button) v).setText("Signing in...");
        System.out.println(loginSql);
        //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        try {
            url = new URL(loginSql);

            new loginTask().execute();

            System.out.println(readStream);

        if(readStream.equals("FAIL"))
            {
                loggedIn = false;
            }
            else
            {
                loggedIn = true;
                //Store the list of arrays for this customer in the arrayList global variable
                Globals.arrayList = Arrays.asList(readStream.split("\\s*#\\s*"));

            }

        } catch (Exception e) {
            System.out.println(e);
            e.printStackTrace();
        }



    if (loggedIn==true)
    {

        startActivity(new Intent(MainActivity.this,LiveStatus.class));
        Thread.sleep(1000);
        finish();
    }
        else
    {
        new AlertDialog.Builder(this)
                .setTitle("Oops...")
                .setMessage("Sign in failed. Please try again.")
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                    }
                })
                .setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        System.exit(0);
                    }
                })
                .setIcon(android.R.drawable.ic_dialog_alert)
                .show();
    }

Logcat shows it caused by InvocationTargetExcecption at signInButtonClick and a NullPointerException.

10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime: FATAL EXCEPTION: main
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime: java.lang.IllegalStateException: Could not execute method of the activity
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2072)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:  Caused by: java.lang.reflect.InvocationTargetException
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at app.ictis.com.myarraydaya.MainActivity.signInButtonClick(MainActivity.java:133)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2067)
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:  Caused by: java.lang.NullPointerException
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at app.ictis.com.myarraydaya.MainActivity.signInButtonClick(MainActivity.java:133) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$1.onClick(View.java:2067) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View.performClick(View.java:2408) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:8816) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:587) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:92) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:123) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:4627) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:521) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
10-11 08:09:07.224 6589-6589/app.ictis.com.myarraydaya E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)

Any ideas please?

Possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Phantômaxx, Oct 11 '15 at 12:16
But how does that relate to the fact then when I debug it line by line it works... — Tym, Oct 11 '15 at 12:25
... until you arrive to `at app.ictis.com.myarraydaya.MainActivity.signInButtonClick(MainActivity.java:133)` — Phantômaxx, Oct 11 '15 at 12:27

score 1 · Answer 1 · answered Oct 11 '15 at 12:43

Discovered that the loggedIn variable needs assigning when I declare it. That's the null pointer. My

new loginTask().execute();

doesn't seem to be executed properly when in normal mode, only when setpping though... which is odd.

Thatnks to Frank for the pointer (no pun inteneded!)

Android Studio New Activity Causes Crash

1 Answers1