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How do I pass data between Activities in Android application?

I have a scenario where, after logging in through a login page, there will be a sign-out button on each activity.

On clicking sign-out, I will be passing the session id of the signed in user to sign-out. Can anyone guide me on how to keep session id available to all activities?

Any alternative to this case

i used sharedpreference its useful also to keep login data on remeber password feature
This works for me. stackoverflow.com/a/7325248/2125322 Thanks Darshan Computing
for such cases try making commomUtils class with sharedprefereces Method... this will keep the code clean and related data at a place . And you will easily be able to Clear specific set of data with just one method of clearing that specific prefrencesFile,without clearing any of default app data...

A
ADM

In your current Activity, create a new Intent:

String value="Hello world";
Intent i = new Intent(CurrentActivity.this, NewActivity.class);    
i.putExtra("key",value);
startActivity(i);

Then in the new Activity, retrieve those values:

Bundle extras = getIntent().getExtras();
if (extras != null) {
    String value = extras.getString("key");
    //The key argument here must match that used in the other activity
}

Use this technique to pass variables from one Activity to the other.


Just an info for those who are so blind like me: if you put an integer in your current activity, you have to get it in the new one via extras.getInt("new_variable_name"). If you try to get it via getString() android see's that a int was given and returns null!
what if the activity is already running, is there need to do startActivity(i); ? I mean, can I make activity A call activity B, and that returns data to activity A ? am I confused ?
I prefer string variable. You can always convert a string to integer or float later.
@FranciscoCorralesMorales did you find anything?
J
Jens Piegsa

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 next activity:

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

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


ok if i pass session id to signout acitivity on successful login and will it work on any activity page to signout or manually i will have to assign it value on each activity??? using above procedure??
Yes, you'd have to make the session ID available to every activity where you want to allow the user to signout. Alternatively, you could store it in the Application object, but then you'd have to manage the state of the session (check if it's valid before using, etc).
Please be aware that the documentation points the following: Add extended data to the intent. The name must include a package prefix, for example the app com.android.contacts would use names like "com.android.contacts.ShowAll".
And to read data from other Activity use Long session_ids=getIntent().getExtras().getLong("EXTRA_SESSION_IDS");
How can we pass data using setData and what is difference between theses two approaches? Which one is better?
J
Jeremy Logan

Passing Intent extras is a good approach as Erich noted.

The Application object is another way though, and it is sometimes easier when dealing with the same state across multiple activities (as opposed to having to get/put it everywhere), or objects more complex than primitives and Strings.

You can extend Application, and then set/get whatever you want there and access it from any Activity (in the same application) with getApplication().

Also keep in mind that other approaches you might see, like statics, can be problematic because they can lead to memory leaks. Application helps solve this too.


+1 for the statics problem. probably the clean up can be resolved by combining a singleton with onCreate/onTerminate method Application class.
Hey, I know this thread was quite a while back, but the link provided is now a dead end. Is there anywhere I can find the example?
@JuiCe The Android Developers blog post on memory leaks is no longer invalid.
P
Peter Mortensen

Source class:

Intent myIntent = new Intent(this, NewActivity.class);
myIntent.putExtra("firstName", "Your First Name Here");
myIntent.putExtra("lastName", "Your Last Name Here");
startActivity(myIntent)

Destination Class (NewActivity class):

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view);

    Intent intent = getIntent();

    String fName = intent.getStringExtra("firstName");
    String lName = intent.getStringExtra("lastName");
}

Can the intent ever be null? Should we check that it is not null?
This is a duplicate of the 3 years older top most voted answer and of Sahil Mahajan Mj's answer and of Mayank Saini's answer
V
Vasily Kabunov

You just have to send extras while calling your intent.

Like this:

Intent intent = new Intent(getApplicationContext(), SecondActivity.class);
intent.putExtra("Variable name", "Value you want to pass");
startActivity(intent);

Now on the OnCreate method of your SecondActivity you can fetch the extras like this.

If the value you sent was in long:

long value = getIntent().getLongExtra("Variable name which you sent as an extra", defaultValue(you can give it anything));

If the value you sent was a String:

String value = getIntent().getStringExtra("Variable name which you sent as an extra");

If the value you sent was a Boolean:

Boolean value = getIntent().getBooleanExtra("Variable name which you sent as an extra", defaultValue);

Please be aware that the documentation points the following: Add extended data to the intent. The name must include a package prefix, for example the app com.android.contacts would use names like "com.android.contacts.ShowAll".
This is a duplicate of the top most voted answer which has been there for 2 years before this answer and of Sahil Mahajan Mj's answer which is 1 year older. Only difference: examples for boolean and long getters which is worth a comment IMO, not an answer.
S
Suragch

It helps me to see things in context. Here are two examples.

Passing Data Forward

https://i.stack.imgur.com/1bUb2.png

Main Activity

Put the data you want to send in an Intent with a key-value pair. See this answer for naming conventions for the key.

Start the Second Activity with startActivity.

MainActivity.java

public class MainActivity extends AppCompatActivity {

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

    // "Go to Second Activity" button click
    public void onButtonClick(View view) {

        // get the text to pass
        EditText editText = (EditText) findViewById(R.id.editText);
        String textToPass = editText.getText().toString();

        // start the SecondActivity
        Intent intent = new Intent(this, SecondActivity.class);
        intent.putExtra(Intent.EXTRA_TEXT, textToPass);
        startActivity(intent);
    }
}

Second Activity

You use getIntent() to get the Intent that started the second activity. Then you can extract the data with getExtras() and the key you defined in the first activity. Since our data is a String we will just use getStringExtra here.

SecondActivity.java

public class SecondActivity extends AppCompatActivity {

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

        // get the text from MainActivity
        Intent intent = getIntent();
        String text = intent.getStringExtra(Intent.EXTRA_TEXT);

        // use the text in a TextView
        TextView textView = (TextView) findViewById(R.id.textView);
        textView.setText(text);
    }
}

Passing Data Back

https://i.stack.imgur.com/sMric.png

Main Activity

Start the Second Activity with startActivityForResult, providing it an arbitrary result code.

Override onActivityResult. This is called when the Second Activity finishes. You can make sure that it is actually the Second Activity by checking the result code. (This is useful when you are starting multiple different activities from the same main activity.)

Extract the data you got from the return Intent. The data is extracted using a key-value pair. I could use any string for the key but I'll use the predefined Intent.EXTRA_TEXT since I'm sending text.

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private static final int SECOND_ACTIVITY_REQUEST_CODE = 0;

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

    // "Go to Second Activity" button click
    public void onButtonClick(View view) {

        // Start the SecondActivity
        Intent intent = new Intent(this, SecondActivity.class);
        startActivityForResult(intent, SECOND_ACTIVITY_REQUEST_CODE);
    }

    // This method is called when the second activity finishes
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // check that it is the SecondActivity with an OK result
        if (requestCode == SECOND_ACTIVITY_REQUEST_CODE) {
            if (resultCode == RESULT_OK) {

                // get String data from Intent
                String returnString = data.getStringExtra(Intent.EXTRA_TEXT);

                // set text view with string
                TextView textView = (TextView) findViewById(R.id.textView);
                textView.setText(returnString);
            }
        }
    }
}

Second Activity

Put the data that you want to send back to the previous activity into an Intent. The data is stored in the Intent using a key-value pair. I chose to use Intent.EXTRA_TEXT for my key.

Set the result to RESULT_OK and add the intent holding your data.

Call finish() to close the Second Activity.

SecondActivity.java

public class SecondActivity extends AppCompatActivity {

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

    // "Send text back" button click
    public void onButtonClick(View view) {

        // get the text from the EditText
        EditText editText = (EditText) findViewById(R.id.editText);
        String stringToPassBack = editText.getText().toString();

        // put the String to pass back into an Intent and close this activity
        Intent intent = new Intent();
        intent.putExtra(Intent.EXTRA_TEXT, stringToPassBack);
        setResult(RESULT_OK, intent);
        finish();
    }
}

Wow, thank you! This was quite what I was looking for. It is quite clear when using camera or other externals that I expect results back, but I didn't think to use it internally. You're the first to put it quite so openly.
a
angryITguy

Updated Note that I had mentioned the use of SharedPreference. It has a simple API and is accessible across an application's activities. But this is a clumsy solution, and is a security risk if you pass around sensitive data. It's best to use intents. It has an extensive list of overloaded methods that can be used to better transfer many different data types between activities. Have a look at intent.putExtra. This link presents the use of putExtra quite well.

In passing data between activities, my preferred approach is to create a static method for the relevant activity that includes the required parameters launch the intent. Which then provides easily setup and retrieve parameters. So it can look like this

public class MyActivity extends Activity {
    public static final String ARG_PARAM1 = "arg_param1";
...
public static getIntent(Activity from, String param1, Long param2...) {
    Intent intent = new Intent(from, MyActivity.class);
        intent.putExtra(ARG_PARAM1, param1);
        intent.putExtra(ARG_PARAM2, param2);
        return intent;
}

....
// Use it like this.
startActivity(MyActvitiy.getIntent(FromActivity.this, varA, varB, ...));
...

Then you can create an intent for the intended activity and ensure you have all the parameters. You can adapt for fragments to. A simple example above, but you get the idea.


I like your answer best... Passing it via the intent means that almost everywhere I start an activity you will have to remember to include the sessionId. By putting it in the SharedPreferences you can get it anytime from any activity. :0)
@bytebender I know this is a bit late for the response, I appreciate that you like my original answer for its simlpicity, but I would be careful to storing session ID in shared preferences. If you must store it on hard storage then use encryption. If you can use an authentication frameworks that employs JWT, it will include refreshTokens which are safer for long term storage, and then keep the current session token as a public property of a custom Application object to easily access authentication tokens, and reduce overhead on activity intent signatures.
p
ponkin

Try to do the following:

Create a simple "helper" class (factory for your Intents), like this:

import android.content.Intent;

public class IntentHelper {
    public static final Intent createYourSpecialIntent(Intent src) {
          return new Intent("YourSpecialIntent").addCategory("YourSpecialCategory").putExtras(src);
    }
}

This will be the factory for all your Intents. Everytime you need a new Intent, create a static factory method in IntentHelper. To create a new Intent you should just say it like this:

IntentHelper.createYourSpecialIntent(getIntent());

In your activity. When you want to "save" some data in a "session" just use the following:

IntentHelper.createYourSpecialIntent(getIntent()).putExtra("YOUR_FIELD_NAME", fieldValueToSave);

And send this Intent. In the target Activity your field will be available as:

getIntent().getStringExtra("YOUR_FIELD_NAME");

So now we can use Intent like same old session (like in servlets or JSP).


V
Vaibhav Sharma

You can also pass custom class objects by making a parcelable class. Best way to make it parcelable is to write your class and then simply paste it to a site like http://www.parcelabler.com/. Click on build and you will get new code. Copy all of this and replace the original class contents. Then-

Intent intent = new Intent(getBaseContext(), NextActivity.class);
Foo foo = new Foo();
intent.putExtra("foo", foo);
startActivity(intent);

and get the result in NextActivity like-

Foo foo = getIntent().getExtras().getParcelable("foo");

Now you can simply use the foo object like you would have used.


佚名

Another way is to use a public static field in which you store data, i.e.:

public class MyActivity extends Activity {

  public static String SharedString;
  public static SomeObject SharedObject;

//...

I really wonder why your suggestion did't get votes, it's simpler and more practical.
um... doesn't this violates OO principles?
@ChristianVielma well, it's more like a gray area... you can do it many ways, to me it seems like a clean "get away", so... it's up to you(the developer) to make the decision if it works good for you or not, I like this way because it's easier to follow, but it can get very dirty very fast...
why do you say this gets dirty? Doesn't iOS do this to pass data between viewcontrollers by setting "properties" which is similar to this? This is so much easier than using intents
Yes, you pass data between view controllers, but not with static properties. The problem is it's not a property on the desired activity instance. The way Android launches activities via startActivity(), it doesn't instantly instantiate the object and allow the developer to set an instance variable. It's pretty annoying...
P
Peter Mortensen

The most convenient way to pass data between activities is by passing intents. In the first activity from where you want to send data, you should add code,

String str = "My Data"; //Data you want to send
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra("name",str); //Here you will add the data into intent to pass bw activites
v.getContext().startActivity(intent);

You should also import

import android.content.Intent;

Then in the next Acitvity(SecondActivity), you should retrieve the data from the intent using the following code.

String name = this.getIntent().getStringExtra("name");

This is a duplicate of the top most voted answer which has been there for even 1 year more.
P
Peter Mortensen

You can use SharedPreferences...

Logging. Time store session id in SharedPreferences SharedPreferences preferences = getSharedPreferences("session",getApplicationContext().MODE_PRIVATE); Editor editor = preferences.edit(); editor.putString("sessionId", sessionId); editor.commit(); Signout. Time fetch session id in sharedpreferences SharedPreferences preferences = getSharedPreferences("session", getApplicationContext().MODE_PRIVATE); String sessionId = preferences.getString("sessionId", null);

If you don't have the required session id, then remove sharedpreferences:

SharedPreferences settings = context.getSharedPreferences("session", Context.MODE_PRIVATE);
settings.edit().clear().commit();

That is very useful, because one time you save the value and then retrieve anywhere of activity.


d
demo

From Activity

 int n= 10;
 Intent in = new Intent(From_Activity.this,To_Activity.class);
 Bundle b1 = new Bundle();
 b1.putInt("integerNumber",n);
 in.putExtras(b1);
 startActivity(in);

To Activity

 Bundle b2 = getIntent().getExtras();
 int m = 0;
 if(b2 != null)
  {
     m = b2.getInt("integerNumber");
  }

A
Ajay Venugopal

The standard approach.

Intent i = new Intent(this, ActivityTwo.class);
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete);
String getrec=textView.getText().toString();
Bundle bundle = new Bundle();
bundle.putString(“stuff”, getrec);
i.putExtras(bundle);
startActivity(i);

Now in your second activity retrieve your data from the bundle:

Get the bundle

Bundle bundle = getIntent().getExtras();

Extract the data…

String stuff = bundle.getString(“stuff”); 

Duplicate as already proposed by PRABEESH R K in 2012. And could be reduced to the i.putExtras()/getIntent().getString() which is proposed by 6 other answers...
K
Khemraj Sharma

Kotlin

Pass from First Activity

val intent = Intent(this, SecondActivity::class.java)
intent.putExtra("key", "value")
startActivity(intent)

Get in Second Activity

val value = intent.getStringExtra("key")

Suggestion

Always put keys in constant file for more managed way.

companion object {
    val KEY = "key"
}

val value = intent.getStringExtra("key")
R
Raceimaztion

You can send data between activities using intent object. Consider you have two activities namely FirstActivity and SecondActivity.

Inside FirstActivity:

Using Intent:

i = new Intent(FirstActivity.this,SecondActivity.class);
i.putExtra("key", value);
startActivity(i)

Inside SecondActivity

Bundle bundle= getIntent().getExtras();

Now you can use different bundle class methods to get values passed from FirstActivity by Key.

E.g. bundle.getString("key"),bundle.getDouble("key") ,bundle.getInt("key") etc.


Duplicate: The Bundle based approach was already proposed by PRABEESH R K in 2012 and Ajay Venugopal. And could be reduced to the i.putExtras()/getIntent().getString() which is proposed by 7 other answers...
c
capt.swag

If you want to tranfer bitmap between Activites/Fragments

Activity

To pass a bitmap between Activites

Intent intent = new Intent(this, Activity.class);
intent.putExtra("bitmap", bitmap);

And in the Activity class

Bitmap bitmap = getIntent().getParcelableExtra("bitmap");

Fragment

To pass a bitmap between Fragments

SecondFragment fragment = new SecondFragment();
Bundle bundle = new Bundle();
bundle.putParcelable("bitmap", bitmap);
fragment.setArguments(bundle);

To receive inside the SecondFragment

Bitmap bitmap = getArguments().getParcelable("bitmap");

Transfering Large Bitmaps

If you are getting failed binder transaction, this means you are exceeding the binder transaction buffer by transferring large element from one activity to another activity.

So in that case you have to compress the bitmap as an byte's array and then uncompress it in another activity, like this

In the FirstActivity

Intent intent = new Intent(this, SecondActivity.class);

ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPG, 100, stream);
byte[] bytes = stream.toByteArray(); 
intent.putExtra("bitmapbytes",bytes);

And in the SecondActivity

byte[] bytes = getIntent().getByteArrayExtra("bitmapbytes");
Bitmap bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

P
Peter Mortensen
Intent intent = new Intent(YourCurrentActivity.this, YourActivityName.class);
intent.putExtra("NAme","John");
intent.putExtra("Id",1);
startActivity(intent);

You can retrieve it in another activity. Two ways:

int id = getIntent.getIntExtra("id", /* defaltvalue */ 2);

The second way is:

Intent i = getIntent();
String name = i.getStringExtra("name");

This is a duplicate of the 3 years older top most voted answer and of Sahil Mahajan Mj's answer and of Mayank Saini's answer and Md. Rahman's answer
C
Community

Supplemental Answer: Naming Conventions for the Key String

The actual process of passing data has already been answered, however most of the answers use hard coded strings for the key name in the Intent. This is usually fine when used only within your app. However, the documentation recommends using the EXTRA_* constants for standardized data types.

Example 1: Using Intent.EXTRA_* keys

First activity

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(Intent.EXTRA_TEXT, "my text");
startActivity(intent);

Second activity:

Intent intent = getIntent();
String myText = intent.getExtras().getString(Intent.EXTRA_TEXT);

Example 2: Defining your own static final key

If one of the Intent.EXTRA_* Strings does not suit your needs, you can define your own at the beginning of the first activity.

static final String EXTRA_STUFF = "com.myPackageName.EXTRA_STUFF";

Including the package name is just a convention if you are only using the key in your own app. But it is a necessity to avoid naming conflicts if you are creating some sort of service that other apps can call with an Intent.

First activity:

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(EXTRA_STUFF, "my text");
startActivity(intent);

Second activity:

Intent intent = getIntent();
String myText = intent.getExtras().getString(FirstActivity.EXTRA_STUFF);

Example 3: Using a String resource key

Although not mentioned in the documentation, this answer recommends using a String resource to avoid dependencies between activities.

strings.xml

 <string name="EXTRA_STUFF">com.myPackageName.MY_NAME</string>

First activity

Intent intent = new Intent(getActivity(), SecondActivity.class);
intent.putExtra(getString(R.string.EXTRA_STUFF), "my text");
startActivity(intent);

Second activity

Intent intent = getIntent();
String myText = intent.getExtras().getString(getString(R.string.EXTRA_STUFF));

T
THANN Phearum

Here is my best practice and it helps a lot when the project is huge and complex.

Suppose that I have 2 activities, LoginActivity and HomeActivity. I want to pass 2 parameters (username & password) from LoginActivity to HomeActivity.

First, I create my HomeIntent

public class HomeIntent extends Intent {

    private static final String ACTION_LOGIN = "action_login";
    private static final String ACTION_LOGOUT = "action_logout";

    private static final String ARG_USERNAME = "arg_username";
    private static final String ARG_PASSWORD = "arg_password";


    public HomeIntent(Context ctx, boolean isLogIn) {
        this(ctx);
        //set action type
        setAction(isLogIn ? ACTION_LOGIN : ACTION_LOGOUT);
    }

    public HomeIntent(Context ctx) {
        super(ctx, HomeActivity.class);
    }

    //This will be needed for receiving data
    public HomeIntent(Intent intent) {
        super(intent);
    }

    public void setData(String userName, String password) {
        putExtra(ARG_USERNAME, userName);
        putExtra(ARG_PASSWORD, password);
    }

    public String getUsername() {
        return getStringExtra(ARG_USERNAME);
    }

    public String getPassword() {
        return getStringExtra(ARG_PASSWORD);
    }

    //To separate the params is for which action, we should create action
    public boolean isActionLogIn() {
        return getAction().equals(ACTION_LOGIN);
    }

    public boolean isActionLogOut() {
        return getAction().equals(ACTION_LOGOUT);
    }
}

Here is how I pass the data in my LoginActivity

public class LoginActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        String username = "phearum";
        String password = "pwd1133";
        final boolean isActionLogin = true;
        //Passing data to HomeActivity
        final HomeIntent homeIntent = new HomeIntent(this, isActionLogin);
        homeIntent.setData(username, password);
        startActivity(homeIntent);

    }
}

Final step, here is how I receive the data in HomeActivity

public class HomeActivity extends AppCompatActivity {

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

        //This is how we receive the data from LoginActivity
        //Make sure you pass getIntent() to the HomeIntent constructor
        final HomeIntent homeIntent = new HomeIntent(getIntent());
        Log.d("HomeActivity", "Is action login?  " + homeIntent.isActionLogIn());
        Log.d("HomeActivity", "username: " + homeIntent.getUsername());
        Log.d("HomeActivity", "password: " + homeIntent.getPassword());
    }
}

Done! Cool :) I just want to share my experience. If you working on small project this shouldn't be the big problem. But when your working on big project, it really pain when you want to do refactoring or fixing bugs.


P
Peter Mortensen

The passing of data between activities is mainly by means of an intent object.

First you have to attach the data to the intent object with the use of the Bundle class. Then call the activity using either startActivity() or startActivityForResult() methods.

You can find more information about it, with an example from the blog post Passing data to an Activity.


This is more or less the same as using the Intent provided methods directly (Intent#putExtra()). But adds another Bundle and makes things more complicated.
R
Rohit Gurjar

You can try Shared Preference, it may be a good alternative for sharing data between the activities

To save session id -

SharedPreferences pref = myContexy.getSharedPreferences("Session 
Data",MODE_PRIVATE);
SharedPreferences.Editor edit = pref.edit();
edit.putInt("Session ID", session_id);
edit.commit();

To get them -

SharedPreferences pref = myContexy.getSharedPreferences("Session Data", MODE_PRIVATE);
session_id = pref.getInt("Session ID", 0);

Duplicate: This approach was already propsed by Ravi Parsania in 2014
r
robe007

You can use Intent

Intent mIntent = new Intent(FirstActivity.this, SecondActivity.class);
mIntent.putExtra("data", data);
startActivity(mIntent);

Another way could be using singleton pattern also:

public class DataHolder {

 private static DataHolder dataHolder;
 private List<Model> dataList;

 public void setDataList(List<Model>dataList) {
    this.dataList = dataList;
 }

 public List<Model> getDataList() {
    return dataList;
 }

 public synchronized static DataHolder getInstance() {
    if (dataHolder == null) {
       dataHolder = new DataHolder();
    }
    return dataHolder;
 }
}

From your FirstActivity

private List<Model> dataList = new ArrayList<>();
DataHolder.getInstance().setDataList(dataList);

On SecondActivity

private List<Model> dataList = DataHolder.getInstance().getDataList();

Duplicate: The intent approach is already proposed by the top most voted answer and of Sahil Mahajan Mj's answer and of Mayank Saini's answer and Md. Rahman's answer, Dilavar M's answer, android developer's answer, sahulab. Singleton: Rodion Altshuler answer
D
Diesel

1st way: In your current Activity, when you create object of intent to open new screen:

  String value="xyz";
  Intent intent = new Intent(CurrentActivity.this, NextActivity.class);    
  intent.putExtra("key", value);
  startActivity(intent);

Then in the nextActivity in onCreate method, retrieve those values which you pass from previous activity:

  if (getIntent().getExtras() != null) {
      String value = getIntent().getStringExtra("key");
      //The key argument must always match that used send and retrive value from one activity to another.
  }

2nd way: You can create bundle object and put values in bundle and then put bundle object in intent from your current activity -

  String value="xyz";
  Intent intent = new Intent(CurrentActivity.this, NextActivity.class);  
  Bundle bundle = new Bundle();
  bundle.putInt("key", value);  
  intent.putExtra("bundle_key", bundle);
  startActivity(intent);

Then in the nextActivity in onCreate method, retrieve those values which you pass from previous activity:

  if (getIntent().getExtras() != null) {
      Bundle bundle = getIntent().getStringExtra("bundle_key");    
      String value = bundle.getString("key");
      //The key argument must always match that used send and retrive value from one activity to another.
  }

You can also use bean class to pass data between classes using serialization.


m
marc_s

Start another activity from this activity pass parameters via Bundle Object

Intent intent = new Intent(getBaseContext(), YourActivity.class);
intent.putExtra("USER_NAME", "xyz@gmail.com");
startActivity(intent);

Retrieve on another activity (YourActivity)

String s = getIntent().getStringExtra("USER_NAME");

This is ok for simple kind data type. But if u want to pass complex data in between activity u need to serialize it first.

Here we have Employee Model

class Employee{
    private String empId;
    private int age;
    print Double salary;

    getters...
    setters...
}

You can use Gson lib provided by google to serialize the complex data like this

String strEmp = new Gson().toJson(emp);
Intent intent = new Intent(getBaseContext(), YourActivity.class);
intent.putExtra("EMP", strEmp);
startActivity(intent);

Bundle bundle = getIntent().getExtras();
String empStr = bundle.getString("EMP");
            Gson gson = new Gson();
            Type type = new TypeToken<Employee>() {
            }.getType();
            Employee selectedEmp = gson.fromJson(empStr, type);

O
Oleg Vaskevich
/*
 * If you are from transferring data from one class that doesn't
 * extend Activity, then you need to do something like this.
 */ 

public class abc {
    Context context;

    public abc(Context context) {
        this.context = context;
    }

    public void something() {
        context.startactivity(new Intent(context, anyone.class).putextra("key", value));
    }
}

D
Darius

I recently released Vapor API, a jQuery flavored Android framework that makes all sorts of tasks like this simpler. As mentioned, SharedPreferences is one way you could do this.

VaporSharedPreferences is implemented as Singleton so that is one option, and in Vapor API it has a heavily overloaded .put(...) method so you don't have to explicitly worry about the datatype you are committing - providing it is supported. It is also fluent, so you can chain calls:

$.prefs(...).put("val1", 123).put("val2", "Hello World!").put("something", 3.34);

It also optionally autosaves changes, and unifies the reading and writing process under-the-hood so you don't need to explicitly retrieve an Editor like you do in standard Android.

Alternatively you could use an Intent. In Vapor API you can also use the chainable overloaded .put(...) method on a VaporIntent:

$.Intent().put("data", "myData").put("more", 568)...

And pass it as an extra, as mentioned in the other answers. You can retrieve extras from your Activity, and furthermore if you are using VaporActivity this is done for you automatically so you can use:

this.extras()

To retrieve them at the other end in the Activity you switch to.

Hope that is of interest to some :)


@BaneeIshaqueK yep sorry, haven't maintained this for a while. Have updated link to point directly to the Github for the project in case it helps. ps. Not sure what I was thinking for that license... apologies
N
Nico Haase

First Activity:

Intent intent = new Intent(getApplicationContext(), ClassName.class);
intent.putExtra("Variable name", "Value you want to pass");
startActivity(intent);

Second Activity:

String str= getIntent().getStringExtra("Variable name which you sent as an extra");

T
The Billionaire Guy

Write following code in CurrentActivity.java

Intent i = new Intent(CurrentActivity.this, SignOutActivity.class);
i.putExtra("SESSION_ID",sessionId);
startActivity(i);

Access SessionId in SignOutActivity.java is following way

public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sign_out);
    Intent intent = getIntent();
    
    // check intent is null or not
    if(intent != null){
        String sessionId = intent.getStringExtra("SESSION_ID");
        Log.d("Session_id : " + sessionId);
    }
    else{
        Toast.makeText(SignOutActivity.this, "Intent is null", Toast.LENGTH_SHORT).show();
    }
}

@Murmel, I feel this is simple and doesn't contain some unnecessary code like the others'. Also, it's not an exact, copy-pasted one. Maybe he couldn't check all the possibly 53 answers? This came first for me when I searched the page for "putex"- using Ctrl+F. I was relieved after seeing this same kind of code; it's not bloated either.
P
Patricia

Use a global class:

public class GlobalClass extends Application
{
    private float vitamin_a;


    public float getVitaminA() {
        return vitamin_a;
    }

    public void setVitaminA(float vitamin_a) {
        this.vitamin_a = vitamin_a;
    }
}

You can call the setters and the getters of this class from all other classes. Do do that, you need to make a GlobalClass-Object in every Actitity:

GlobalClass gc = (GlobalClass) getApplication();

Then you can call for example:

gc.getVitaminA()

Overriding application - this is duplicate of Whome's answer