NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

Question

I am getting this error at runtime.

java.lang.RuntimeException: Unable to start activity ComponentInfo java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

StackTrace:

01-12 03:44:54.270: E/AndroidRuntime(1437): FATAL EXCEPTION: main
01-12 03:44:54.270: E/AndroidRuntime(1437): Process: home.saket, PID: 1437
01-12 03:44:54.270: E/AndroidRuntime(1437): java.lang.RuntimeException: Unable to start activity ComponentInfo{home.saket/home.saket.addmember.Add_Update_User}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread.access$800(ActivityThread.java:144)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.os.Handler.dispatchMessage(Handler.java:102)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.os.Looper.loop(Looper.java:135)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread.main(ActivityThread.java:5221)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at java.lang.reflect.Method.invoke(Native Method)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at java.lang.reflect.Method.invoke(Method.java:372)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
01-12 03:44:54.270: E/AndroidRuntime(1437): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference
01-12 03:44:54.270: E/AndroidRuntime(1437):     at home.saket.addmember.Add_Update_User.onCreate(Add_Update_User.java:38)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.Activity.performCreate(Activity.java:5933)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
01-12 03:44:54.270: E/AndroidRuntime(1437):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
01-12 03:44:54.270: E/AndroidRuntime(1437):     ... 10 more
01-12 03:44:54.272: W/ActivityManager(472):   Force finishing activity home.saket/.addmember.Add_Update_User
01-12 03:44:54.273: E/ActivityManager(472): Invalid thumbnail dimensions: 384x384

Below I am posted the codes and pointed out the error line.

Add_Update_User.java:

@Override
    protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_update_screen);

    // set screen
    Set_Add_Update_Screen();

    // set visibility of view as per calling activity
    String called_from = getIntent().getStringExtra("called");

    if (called_from.equalsIgnoreCase("add")) {  --->38th error line
        add_view.setVisibility(View.VISIBLE);
        update_view.setVisibility(View.GONE);
    } else {

        update_view.setVisibility(View.VISIBLE);
        add_view.setVisibility(View.GONE);
        USER_ID = Integer.parseInt(getIntent().getStringExtra("USER_ID"));

        Contact c = dbHandler.Get_Contact(USER_ID);  

        add_name.setText(c.getName());
        add_mobile.setText(c.getPhoneNumber());
        add_email.setText(c.getEmail());
        // dbHandler.close();
    }
    }

can you try this for me plz? if("add".equalsIgnoreCase(called_from)){ — Kick Buttowski, Jan 12 '15 at 04:01
@KickButtowski I tried yours.works fine.can you post your answer and explain it? — Steve, Jan 12 '15 at 04:07
I cannot post my answer since your post has been marked as duplicate. :( — Kick Buttowski, Jan 12 '15 at 04:11
Everybody told me to suggest for null check.your answer was solved me.But now you can't post your answer because it is closed.sorry for that. @KickButtowski — Steve, Jan 12 '15 at 04:11
it was a good question anyway. I am sure what I suggested is right but I cannot remember the reason. hope you found that — Kick Buttowski, Jan 12 '15 at 04:21
I didn't have skype.I am accepted Elliott Frisch.this is the only answer I am looking for other than yours. @KickButtowski — Steve, Jan 12 '15 at 04:23
@KickButtowski I am not worried for marked this as duplicate.But I couldn't accept your answer. — Steve, Jan 12 '15 at 04:25
it is totally fine as long as you are happy. thank you so much :) — Kick Buttowski, Jan 12 '15 at 04:25
take a look at my answer in this post for more info if you like http://stackoverflow.com/questions/27392935/checking-if-a-jtextfield-contains-correct-string/27392947#27392947 — Kick Buttowski, Jan 12 '15 at 04:29
you may wanna see this discussion as well http://chat.stackoverflow.com/rooms/68625/madandi — Kick Buttowski, Jan 12 '15 at 05:16

Elliott Frisch · Accepted Answer · 2015-01-12T04:26:47.587

66

called_from must be null. Add a test against that condition like

if (called_from != null && called_from.equalsIgnoreCase("add")) {

or you could use Yoda conditions (per the Advantages in the linked Wikipedia article it can also solve some types of unsafe null behavior they can be described as placing the constant portion of the expression on the left side of the conditional statement)

if ("add".equalsIgnoreCase(called_from)) { // <-- safe if called_from is null

edited Jan 12 '15 at 04:26

answered Jan 12 '15 at 04:04

Elliott Frisch

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I love Yoda conditions...+1 for that idea! – Alex K Jan 12 '15 at 04:05
can you explain the Yoda Conditions here plz? – Kick Buttowski Jan 12 '15 at 04:22
@KickButtowski Edited to include some explanation. – Elliott Frisch Jan 12 '15 at 04:27
@ElliottFrisch I still do not understand how it throws NPE. how ? – Kick Buttowski Jan 12 '15 at 04:44
@Kick The Yoda conditions don't throw NPE, that is the point of using them. What are you asking? – Elliott Frisch Jan 12 '15 at 04:50
@ElliottFrisch if we forget about youda condition, why it throws npe when we do not use youda condition? – Kick Buttowski Jan 12 '15 at 04:51
Because `called_from` is `null`; it must be. OP indicated the line in source, and it was `if (called_from.equalsIgnoreCase("add")) { --->38th error line` if you say `null.equalsIgnoreCase("add")` you get a NPE. – Elliott Frisch Jan 12 '15 at 04:53
Saved my day! I can't believe this simple thing will spare me a sleep.. – mboy Feb 22 '16 at 13:22

Alex K · Answer 2 · 2021-10-10T15:09:30.327

This is the error line:

if (called_from.equalsIgnoreCase("add")) {  --->38th error line

This means that called_from is null. Simple check if it is null before using it:

String called_from = getIntent().getStringExtra("called");

if (called_from != null && called_from.equalsIgnoreCase("add")) {
    // do whatever
} else {
    // do whatever
}

That way, if called_from is null, it'll execute the else part of your conditional.

score 4 · Answer 3 · answered Jan 12 '15 at 04:05

The exception occurs due to this statement,

called_from.equalsIgnoreCase("add")

It seem that the previous statement

String called_from = getIntent().getStringExtra("called");

returned a null reference.

You can check whether the intent to start this activity contains such a key "called".

NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.equalsIgnoreCase(java.lang.String)' on a null object reference

3 Answers3

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