Action Bar null pointer exception

Question

I am trying to change the title of an Action Bar but I am having the null pointer exception, I am not very expert so I don't really know how to catch the exception or do it properly, basically this is the line I am having problem with:

public class MainActivity extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getActionBar().setIcon(R.drawable.profile_banner_orange);
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    switch (id){

        case R.id.action_settings:
            return true;
        case R.id.profile_ic:
            openItemManager();
            return true;
    }

    return super.onOptionsItemSelected(item);
}

public void openItemManager(){
    Intent myIntent = new Intent(MainActivity.this, ItemManagerActivity.class);
    //myIntent.putExtra("key", value); //Optional parameters
    MainActivity.this.startActivity(myIntent);

}

Android Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.blitzar.stiktag" >

<!-- To auto-complete the email text field in the login form with the user's emails -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_PROFILE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />

<application
    android:allowBackup="true"
    android:icon="@drawable/icon_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".Activities.LoginActivity"
        android:label="@string/app_name"
        android:windowSoftInputMode="adjustResize|stateVisible" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".Activities.ItemManagerActivity"
        android:label="@string/title_activity_item_manager" >
    </activity>
    <activity
        android:name=".Activities.MainActivity"
        android:label="@string/title_activity_main"
        android:icon="@drawable/profile_banner_orange" >
    </activity>
</application>

</manifest>

and this is the activity_main XML:

<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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.blitzar.stiktag.Activities.MainActivity">

<LinearLayout
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="51dp">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/tag"
        android:id="@+id/button3" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/search"
        android:id="@+id/button4" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/found"
        android:id="@+id/button" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/lost"
        android:id="@+id/button2" />
</LinearLayout>

</RelativeLayout>

This is the log if that is any help:

08-12 21:37:39.113      450-450/com.blitzar.stiktag E/AndroidRuntime﹕ FATAL     EXCEPTION: main
Process: com.blitzar.stiktag, PID: 450
java.lang.RuntimeException: Unable to start activity   ComponentInfo{com.blitzar.stiktag/com.blitzar.stiktag.Activities.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setIcon(int)' on a null object reference
        at  android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2394)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2452)
        at android.app.ActivityThread.access$900(ActivityThread.java:172)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1302)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5586)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual  method 'void android.app.ActionBar.setIcon(int)' on a null object reference
        at  com.blitzar.stiktag.Activities.MainActivity.onCreate(MainActivity.java:20)
        at android.app.Activity.performCreate(Activity.java:5451)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2358)

Any help will be highly appreciated

yet another ... use it after super.onCreate/setContentView

Selvin
– Selvin

2015-08-12 11:12:27 +00:00
Commented Aug 12, 2015 at 11:12 — Selvin
– Selvin, Commented Aug 12, 2015 at 11:12
post your error logs

Arun Shankar
– Arun Shankar

2015-08-12 11:22:32 +00:00
Commented Aug 12, 2015 at 11:22 — Arun Shankar
– Arun Shankar, Commented Aug 12, 2015 at 11:22
Are you using AppCompatActivity or ActionBarActivity?

capt.swag
– capt.swag

2015-08-12 11:24:52 +00:00
Commented Aug 12, 2015 at 11:24 — capt.swag
– capt.swag, Commented Aug 12, 2015 at 11:24
The class extends ActionBarActivity

Jhonycage
– Jhonycage

2015-08-12 11:30:37 +00:00
Commented Aug 12, 2015 at 11:30 — Jhonycage
– Jhonycage, Commented Aug 12, 2015 at 11:30
I've updated my solution.

capt.swag
– capt.swag

2015-08-12 12:02:23 +00:00
Commented Aug 12, 2015 at 12:02 — capt.swag
– capt.swag, Commented Aug 12, 2015 at 12:02

Aritra Roy · Accepted Answer · 2015-08-12 12:26:29Z

5

Please use the actionbar only after setting the views.

First use these,

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

then this,

getSupportActionBar().setIcon(R.drawable.profile_banner_orange);

UPDATE

Thanks for updating the question. Now the problem is obvious.

See, you are using the ActionBarActivity class which has long been deprecated. You should be seeing a strike-through in Android Studio. It is RECOMMENDED to use AppCompatActivity

Just extend AppCompatActivity and use getSupportActionBar(). You will not be getting any NullPointerException anymore.

If you have any problem displaying the icon, please try this,

 getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_HOME | 
   ActionBar.DISPLAY_SHOW_TITLE | ActionBar.DISPLAY_HOME_AS_UP | ActionBar.DISPLAY_USE_LOGO);
   actionBar.setIcon(R.drawable.ic_launcher);

edited Aug 12, 2015 at 12:26

answered Aug 12, 2015 at 11:12

Aritra Roy

15.7k12 gold badges76 silver badges111 bronze badges

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9 Comments

Jhonycage Over a year ago

I use to have it that way, but still throwing an exception, I tried again but nothing changes

Aritra Roy Over a year ago

Please post your XML layout.

Jhonycage Over a year ago

Thanks I have posted the android manifest, is that what you mean?

Aritra Roy Over a year ago

No, I said the XML layout, namely activity_main

Aritra Roy Over a year ago

The layout is okay. You need to post more code from your Activity for me to debug.

|

IntelliJ Amiya · Accepted Answer · 2015-08-12 11:53:32Z

2

Before initializing any view please call setContentView()

 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 ActionBar actionBar = getActionBar();
 actionBar.setIcon(R.drawable.profile_banner_orange);

Please update your style.xml

<resources>

<style name="AppBaseTheme"  parent="@android:style/Theme.Holo.Light">


</style>

<style name="AppTheme" parent="android:Theme.Holo.Light">  </style>

edited Aug 12, 2015 at 11:53

answered Aug 12, 2015 at 11:14

IntelliJ Amiya

75.8k15 gold badges169 silver badges199 bronze badges

14 Comments

Jhonycage Over a year ago

Hi thanks for answer, I already tried either way but still throwing exception

IntelliJ Amiya Over a year ago

your class extends what ?? Actionbaractivity or other

Jhonycage Over a year ago

I tried that as well, but it still gives me the warning and the app crashes, Im getting message when I put mouse over the extends ActionBarActivity which i don't know what it is but it says: android.support.v7.app.ActionBarActivity is deprecated

Jhonycage Over a year ago

I don't have much experience so when I added a theme for the layout i added holo light dark action bar so it just automatic extended actionbaractivity

Jhonycage Over a year ago

I posted the log, I am using android Studio

|

capt.swag · Accepted Answer · 2015-08-12 12:18:44Z

1

You are using android.app.ActionBar. So you have to do the following

Remove the import statement import android.app.ActionBar;
Now import the support ActionBar class using import android.support.v7.app.ActionBar;
Then copy/paste the cody given below.
Done

getSupportActionBar() is used when your class extends from support library, ie AppCompatActivity or ActionBarActivity. In that case the proper way to get reference to ActionBar is

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getSupportActionBar().setIcon(R.drawable.profile_banner_orange);
    }

The Action Bar follows the material design guidelines and uses a Toolbar. As you can read here:

The use of application icon plus title as a standard layout is discouraged on API 21 devices and newer. If you would like an application icon, you can use the method setLogo().

edited Aug 12, 2015 at 12:18

answered Aug 12, 2015 at 11:29

capt.swag

10.7k2 gold badges45 silver badges43 bronze badges

9 Comments

Jhonycage Over a year ago

Thanks for help, but still not working, is giving me the same warning

capt.swag Over a year ago

Are you getting warning or error? Did your app crash, when you ran the code?

Jhonycage Over a year ago

yes the app is crashing I just posted the log thanks

capt.swag Over a year ago

I've updated the answer. You are using ActionBarActvity, but the import statement of ActionBar is not from the support version. So follow the steps I've given above.

Jhonycage Over a year ago

Thanks I am trying still gives me warning but the app is not crashing, however I cannot see any logo on the title :(, also any idea why i am getting this message: android.support.v7.app.ActionBarActivity is deprecated?

|

Rajesh Jadav · Accepted Answer · 2015-08-12 11:22:05Z

1

You have called

getSupportActionBar().setIcon(R.drawable.profile_banner_orange);

before initilizing your activity's view. so at that time your actionbar is null.

you must call

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

first then your actionbar method.

answered Aug 12, 2015 at 11:22

Rajesh Jadav

12.9k5 gold badges56 silver badges81 bronze badges

Comments

eriq · Accepted Answer · 2015-11-09 21:14:55Z

0

try

setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setIcon(R.drawable.profile_banner_orange);

answered Nov 9, 2015 at 21:14

eriq

1

1 Comment

Brody Over a year ago

Please explain your solution to future questioners.

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