Android Studio :: E/AndroidRuntime﹕ FATAL EXCEPTION:

Question

My app crashed the moment i run it. I need help. Thank you very much in advance.

I'm kinda new on android studio, not sure what i did wrong.

Error:

09-14 02:55:11.013 4502-4502/com.example.adrian.loginregister E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                Process: com.example.adrian.loginregister, PID: 4502
                                                                                java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.adrian.loginregister/com.example.adrian.loginregister.LoginActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
                                                                                    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                                    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                                    at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                                    at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                    at android.os.Looper.loop(Looper.java:148)
                                                                                    at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                    at java.lang.reflect.Method.invoke(Native Method)
                                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                                 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
                                                                                    at com.example.adrian.loginregister.LoginActivity.onCreate(LoginActivity.java:23)
                                                                                    at android.app.Activity.performCreate(Activity.java:6237)
                                                                                    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
                                                                                    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
                                                                                    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
                                                                                    at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                                                                                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
                                                                                    at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                    at android.os.Looper.loop(Looper.java:148) 
                                                                                    at android.app.ActivityThread.main(ActivityThread.java:5417) 
                                                                                    at java.lang.reflect.Method.invoke(Native Method) 
                                                                                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                                                                                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Below are the LoginActivity.java

package com.example.adrian.loginregister;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class LoginActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        final EditText etUsername = (EditText) findViewById(R.id.etUsername);
        final EditText etPassword = (EditText) findViewById(R.id.etPassword);
        final Button bLogin = (Button) findViewById(R.id.bLogin);
        final TextView bRegister = (TextView) findViewById(R.id.bRegister);

        bRegister.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                Intent registerIntent = new Intent(LoginActivity.this, RegisterActivity.class);
                LoginActivity.this.startActivity(registerIntent);
            }
        });
    }
}

This is the activty_login.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.adrian.loginregister.LoginActivity">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/etUsername"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:hint="Username" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/etPassword"
        android:layout_below="@+id/etUsername"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignRight="@+id/etUsername"
        android:layout_alignEnd="@+id/etUsername"
        android:hint="Password" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Login"
        android:id="@+id/bLogin"
        android:layout_below="@+id/etPassword"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Register here"
        android:id="@+id/tvRegister"
        android:layout_below="@+id/bLogin"
        android:layout_centerHorizontal="true" />
</RelativeLayout>

I've been trying to figure out for hours. Can't seem to get it to work. Crashes every time i try to run it.

Possible duplicate of [Android - Null pointer Exception - findViewById()](http://stackoverflow.com/questions/19078461/android-null-pointer-exception-findviewbyid) — OneCricketeer, Sep 14 '16 at 03:45
Are you new to Java as well? You have a NullPointerException. Also worth a look - [What is a NullPointerException](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) and [How to read a stacktrace](http://stackoverflow.com/questions/3988788/what-is-a-stack-trace-and-how-can-i-use-it-to-debug-my-application-errors) — OneCricketeer, Sep 14 '16 at 03:48
Then. `bRegister` might want to be a Button yes? You don't typically set click listeners on TextViews — OneCricketeer, Sep 14 '16 at 03:49
Hi, yes i'm fresh on Java too. bRegister is a textview. Thanks for the tip. I'll read up on NullPointerException. thanks. — Adrian Lee, Sep 14 '16 at 04:07

score 0 · Accepted Answer · answered Sep 14 '16 at 04:14

0

try to change

final TextView bRegister = (TextView) findViewById(R.id.bRegister);

line to

final TextView bRegister = (TextView) findViewById(R.id.tvRegister);

becuase in your xml file you are giving Register TextView Id to tvRegister. your are giving wrong Id in initliazation.

answered Sep 14 '16 at 04:14

Harshad Pansuriya

20,189
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Thank you so much! i didn't even realize that, it solved the problem. I still can't recall why i call for bRegister. Thanks again – Adrian Lee Sep 14 '16 at 04:19

Android Studio :: E/AndroidRuntime﹕ FATAL EXCEPTION:

1 Answers1