Passing Strings Between Activities in Android

Passing strings between activities in android

In your LocationActivity class:

Intent i = new Intent(this, FindAndroidActivity.class);
i.putExtra("KEY",YourData);

In FindAndroidActivity class

Bundle extras = getIntent().getExtras();
if(extras !=null) {
    String value = extras.getString("KEY");
}

Passing strings between activities in Android studio

Method invocation 'activityButton.setOnClickListener(new View.OnClickListener() { public void onClick(View... may produce java.lang.NullPointerException

This means that if in this line:

Button activityButton = (Button) findViewById(R.id.Button);

the operation findViewById(R.id.Button) returns null, the next line will throw a NullPointerException because activityButton value will be null. This could happen if the id passed to findViewById is not found in the layout.

You can check if activityButton is not null and the message will not show up:

    Button activityButton = (Button) findViewById(R.id.Button);
    if (activityButton != null){
        activityButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent startIntent = new Intent(MainActivity.this, SecondaryActivity.class);
                startIntent.putExtra("com.example.owner.Message","Hello SecondaryActivity");
                startActivity(startIntent);
            }
        });
    }

The second problem: you didn't define a variable name in this line:

 Intent = getIntent();

You need to name a variable and then use it in the next line:

 Intent intent= getIntent();
 String message = intent.getStringExtra("com.example.owner.MESSAGE");

Passing strings between activities, intents not working

You are calling launchHomeActivity() after getting Response on OnResponse() and accessToken. But you stored the token on createIntent() which is never called. So call createIntent() on OnResponse() method after getting token.

And this is not best practice to pass token from Activity to Activity. Better would be store the token on SharedPrefrence and access it from anywherer . Make a singleton SharedPreference class and you can use it on whole application.

How do I pass data between Activities in Android application?

The easiest way to do this would be to pass the session id to the signout activity in the Intent you're using to start the activity:

Intent intent = new Intent(getBaseContext(), SignoutActivity.class);
intent.putExtra("EXTRA_SESSION_ID", sessionId);
startActivity(intent);

Access that intent on the next activity:

String sessionId = getIntent().getStringExtra("EXTRA_SESSION_ID");

The docs for Intents has more information (look at the section titled "Extras").

how to pass String Value of One Activity and Can Use in Any activity in android

I suggest to use SharedPreferences
It is really easy to use and you can fetch data in any activities

here is a good explanation of it

Hope it helps you

Pass Strings through several activities

The app crashes when it should open the second activity. It's the following error that makes me believe this is related to the path: "E/AndroidRuntime(7115): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.fm/com.fm.mondev.MeanSelection}: java.lang.NullPointerException: println needs a message"

println needs a message has NOTHING to do with activity anything. Read your logcat!

I get this error when I try to Log a null value, i.e.

String foo = emptyBundle.getString("barValue");
Log.d(TAG, foo) // error, Log output functions cannot output null values.
Log.d(TAG, "barValue: " + barValue);  // outputs "barValue: null"

Make sure whatever you're Logging or System.out.printlning has a value.

How to pass strings in multiple activities

Forward all Extras

You can "forward" all extras using putExtras(intent):

Intent third = new Intent(this, ThirdActivity.class);
third.putExtras(getIntent());
third.putExtra("THIRD", myString);

This will maintain the same key at every step, so if you backtrack (Activity 5 => Activity 3) you can still extract the relevant values for that activity.

Bonus: Use constants to avoid typos

Since your extras might be read in multiple Activities, I would define constants in the final Activity in your flow (I assume a summary or confirmation activity):

public class LastActivity extends AppCompatActivity {

    public static final String EXTRA_NAME = "EXTRA_NAME"
    public static final String EXTRA_EMAIL = "EXTRA_EMAIL"
    public static final String EXTRA_BOOKING_ID = "EXTRA_BOOKING_ID"

    // rest of class
}

Then you don't risk typos when you putExtra or getXxxExtra:

String name = intent.getStringExtra(LastActivity.EXTRA_NAME);