CODEWITHSUNDEEP
javaandroidandroid-intentandroid-activitynullpointerexception
iqueqiorio
iqueqiorio

Reputation: 1187

Android - Pass Data Between Two Activities get NullPointerException

I have 3 activities we will call them A, B and C. A and B both have intents that send the view to C. And design on which one C came from different things happen on C's activity. I pass the data like this from A to C:

Intent intent = new Intent(this, C.class);
    intent.putExtra("Action", "A");
    startActivity(intent);

Then in C's onCreate method I have something like this:

Bundle extras = getIntent().getExtras();
if (extras.getString("Action").equals("A")) {
//DO SOMETHING
}

Then I from B to C I have 

 Intent intent = new Intent(this, C.class);
 startActivity(intent);

And then I get the NullPointerException, I am guessing this is because i have not specifed a String "Action" when going from B to C.

Now I could just add one line for B in this case but, if there were for more activities or a large project this would not be good, because for each activity going to one I would need this.

How can I have it so I don't get this exception without adding an "Action" sting to activity B?

Thanks for the help in advance.

EDIT

If I have this from A to C

Intent intent = new Intent(this, C.class);
    intent.putExtra("Action", "A");
    intent.putExtra("Action2", "A");
    startActivity(intent);

And this from B to C

 Intent intent = new Intent(this, C.class);
    intent.putExtra("Action", "B");
    startActivity(intent);

And then this in onCreate of C it fails when going from B to C:

Bundle extras = getIntent().getExtras();
if (extras != null) {
    if (extras.getString("Action").equals("A")) {
    //DO SOMETHING
    }
    else if (extras.getString("Action2").equals("A")) {
     //DO Stuuf
    }
}

Upvotes: 0

Views: 1888

Answers (7)

Remees M Syde
Remees M Syde

Reputation: 2609

Change the code in C class like this for checking the bundle is null or not.

Bundle extras = getIntent().getExtras();
if(extras != null){
   if(extras.getString("Action") != null)
      if (extras.getString("Action").equals("A")) {
        //DO SOMETHING
      }
   }  
 if(extras.getString("Action2") != null)
      if (extras.getString("Action2").equals("A2")) {
        //DO SOMETHING
      }
   }  
}

Upvotes: 2

havish
havish

Reputation: 373

You are starting the Activity C twice( whenever you call startActivity(intent) ). First time from A and second time from B. Both times you are checking this

Bundle extras = getIntent().getExtras();
if (extras.getString("Action").equals("A")) {
//DO SOMETHING
}

Which is bound to give you a null pointer exception. Put up a break point in your IDE and verify it. why don't you use some static variable to share the info between the activities in case you don't want to instantiate the class C more than once.

Upvotes: 0

W I Z A R D
W I Z A R D

Reputation: 1224

NullPointerException This will Happen because When you are moving from Activity A to C you are passing intent with value and in activity C you are getting that value using Bundle. But When you Move From Activity B to C you are not passing values through intent and in Activity C you have Written this

Bundle extras = getIntent().getExtras();
if (extras.getString("Action").equals("A")) {
//DO SOMETHING
}

at this tme the extra is null So you will get Error.

DO like this

Bundle extras = getIntent().getExtras();
if(extras != null)//This one will check for null
if (extras.getString("Action").equals("A")) {
    //DO SOMETHING
}

EDIT For passing Multiple values from activity

Intent intent= new Intent(this,NextActivity.class);
Bundle extra = new Bundle();
extra.putString("Action1","Value1");
extra.putString("Action2","Value2");
intent.putExtras(extra);
startActivity(intent);

In NextActivity 

Intent i = getIntent();
Bundle extras = i.getExtras();
String strAction1 = extras.getString("Action1");
String strAction2 = extras.getString("Action2");

Upvotes: 0

Naveen
Naveen

Reputation: 830

you are always creating new Intent object when ever you are moving to new activity. Hence this issue. Try to copy required data in new intent and access, them.

Upvotes: 0

incr3dible noob
incr3dible noob

Reputation: 441

Hope this solves

Bundle extras = getIntent().getExtras();
if (extras != null && extras.getString("Action").equals("A")) {
//DO SOMETHING
}

Upvotes: 0

Zeeshan Ahmed
Zeeshan Ahmed

Reputation: 1187

Try this...

Bundle extras = getIntent().getExtras();
if(extras != null){
if (extras.getString("Action").toString().equals("A") || extras.getString("Action").toString() == "A") {
//DO SOMETHING
}
}

Upvotes: 0

Ravi
Ravi

Reputation: 35549

check below code : 

if(getIntent().hasExtra("Action"))
    //if you have passed "Action" from activity
else
   //if you did not pass "Action" from activity

Upvotes: 0

Related Questions