How to pass data both ways between different android applications?

Question

What's the easiest way to pass string variables from one application to another and also return values back? I have access to the source code of both apps, but it has to be two different applications.

I tried with startActivityForResult, but this only seems to work between activies of the same application. When calling an activity from a different package, startActivityForResult returns immediately with RESULT_CANCELED. There seems to be the possibility to solve this with a Service, but isn't that a bit oversized for just some string vars?

Is there an easy and clean way to do this?

Here the code i tried to use for startActivityForResult:

//App A:
            Intent intent = new Intent();
            intent.setAction("com.example.testapp.MESSAGE");
            Bundle b = new Bundle();
            b.putString("loginToken", "263bhqw3jhf6as4yf8j0agtz8h2hj2z9j3hg3g3ggh34uzh2h2ui78h3i9wdnj89x");
            intent.putExtra("MyData", b);

            startActivityForResult(intent, TEST_REQUEST);

    @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    Log.d("pairing", "onActivityResult called");
    // Check which request we're responding to
    if (requestCode == TEST_REQUEST) {
        // Make sure the request was successful
        Log.d("pairing", "got result, resultCode: " + resultCode);
        if (resultCode == RESULT_OK) {
            // The Intent's data Uri identifies which contact was selected.
            if (data.hasExtra("returnMessage")) {
                Toast.makeText(this, data.getExtras().getString("returnMessage"), Toast.LENGTH_LONG).show();
            }

        }
    }
}


            // App B:
        Intent result = new Intent();
        Bundle b = new Bundle();
        b.putString("returnValue", "this is the returned value");
        result.putExtra("MyData", b);
        setResult(Activity.RESULT_OK, result);
        Log.d("pairing", "RESULT_OK set");
        finish();


//App B Manifest
        <activity
        android:name="com.example.testapp"
        android:launchMode="singleTop"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="adjustPan" >
        <intent-filter>
            <action android:name="com.example.testapp.MESSAGE" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:mimeType="text/plain" />
        </intent-filter></activity>

Anybody seeing the mistake? App B always returns immediately with RESULT_CANCELED

EDIT: Right now I'm getting a android.content.activitynotfoundexception no activity found to handle intent { act=com.example.testapp.MESSAGE (has extras) } error. What am I doing wrong?

startActivityForResult should work... Problem seems to be within your code — Selvin, Sep 23 '13 at 18:35
It seems for me this is not possible with startActivityForResult(). It works between Activities of the same app, even with different packages, but not with two different Applications. See [link](http://stackoverflow.com/questions/11919259/how-to-get-startactivityforresult-on-external-activity-to-work) — qefzec, Sep 25 '13 at 08:37

score 2 · Answer 1 · answered Sep 24 '13 at 17:56

2

AIDL is one means of communication between two different applications using Interfaces

http://developer.android.com/guide/components/aidl.html

You can find a working sample in the below tutorial http://manishkpr.webheavens.com/android-aidl-example/

answered Sep 24 '13 at 17:56

Code_Yoga

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score 1 · Accepted Answer · answered Sep 23 '13 at 18:32

1

you can use ContentProvider.This is a better way than others.

answered Sep 23 '13 at 18:32

Ranjit

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For me it seems kinda sad, that I have to set up a ContentProvider to send two or three Strings back. However, this appears to be the most elegant solution. – qefzec Sep 25 '13 at 08:40
Its just a suggesting way for you. you can try other answers also. sharedpreference is a good way also. it depends on your requirements that what and how you are going to use. thank you – Ranjit Sep 25 '13 at 08:50

score 0 · Answer 3 · answered Sep 23 '13 at 18:16

0

SharedPreferences might help you in this regard.

answered Sep 23 '13 at 18:16

Sash_KP

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Hmm would that be a clean way to pass (no need to store) data? So just declare a SharedPreference in one app and use it for both applications? – qefzec Sep 23 '13 at 18:35
The data will be _stored_ locally if you use [SharedPreferences](http://developer.android.com/reference/android/content/SharedPreferences.html).For any particular set of preferences, there is a single instance of this class that all clients share.So modified once,the modified value reflects everywhere.That way data is accessed.I prefer this one than data passing(using intent,putExtra etc). – Sash_KP Sep 24 '13 at 12:14

score 0 · Answer 4 · answered Sep 23 '13 at 18:35

0

I have two apps that i pass data to/from.

App1...
Intent i = new Intent("com.xxx.yyy.MESSAGE");
Bundle b = new Bundle();
b.putString("AAA", getAAA());
i.putExtra("MyData", b);
startActivityForResult(i, "myProcess");

nothing fancy there...

App2...in onResume()...

 Intent i = getIntent();
 if (i != null && i.getAction().equals("com.xxx.yyy.MESSAGE") {
    ...get the data from the bundle
 }

note that the AndroidManifest.xml (for App2) has the following entries for one of the activities

 <intent-filter>
    <action android:name="com.xxx.yyy.MESSAGE"/>
    <category android:name="android.intent.category.DEFAULT"/>
    <data android:mimeType="text/plain"/>
 </intent-filter>

answered Sep 23 '13 at 18:35

David M

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That works when you pass data to App2, but you can't pass something back can you? When I tried that, a RESULT_CANCELED event at onActivityResult returned immediately – qefzec Sep 23 '13 at 18:44
yes...i act on the data (in App2) and pass it back to App1. again, in a bundle...i've turned off my dev machine so i cannot remember the exact way i did it...but it's `standard` (in the docs). App1 picks up in `onActivityResult(xxx, yyy, data)` – David M Sep 23 '13 at 18:46
app1 and app2 are not on the same package? I tried your way but it doesn't work for me. I will provide my code above – qefzec Sep 24 '13 at 07:50
in App2's `onFinish()` i create another Intent that has the data i'm passing back. to return to the calling app (App1) i then call `setResult(RESULT_OK, returnIntent);` unless, of course, i came across an error then i return to App1 with `setResult(RESULT_CANCELED);` – David M Sep 24 '13 at 14:12
I'm not sure what I am doing wrong ... could you maybe provide all the relevant excerpts with Manifests? I would really like to know, what I'm doing wrong ... – qefzec Sep 24 '13 at 14:41
sorry, my development machine is not on a network...are you setting the return code? i.e. `setResult(RESULT_OK, returnIntent);`? i'm not sure what the default is if you leave that out. – David M Sep 24 '13 at 14:45
Also, a minor difference from my code to yours is that you call `finish();` after setting the return code. I have overridden `finish()`...set the return code in there...then call `super.finish();` dunno if that makes a difference, though. – David M Sep 24 '13 at 14:49
When I try your code @DavidM I am unable to run successfully, I get an error stating no such Activity ... Intent i = new Intent("com.xxx.yyy.MESSAGE");<-- does this mean: package name.ActivityName ? I do this and keep getting same error. – LizG Apr 02 '18 at 23:31

score 0 · Answer 5 · answered Nov 13 '14 at 13:32

0

You can exchange messengers between two services that belong to those apps (even if the apps are from two different packages) and communicate using those messengers.

answered Nov 13 '14 at 13:32

MikeL

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score 0 · Answer 6 · answered Jul 21 '15 at 11:19

public class MyParcelable implements Parcelable {
    // You can include parcel data types
    private int mData;
    private String mName;

    // We can also include child Parcelable objects. Assume MySubParcel is such a Parcelable:
    private MySubParcelable mInfo;

    // This is where you write the values you want to save to the `Parcel`.  
    // The `Parcel` class has methods defined to help you save all of your values.  
    // Note that there are only methods defined for simple values, lists, and other Parcelable objects.  
    // You may need to make several classes Parcelable to send the data you want.
    @Override
    public void writeToParcel(Parcel out, int flags) {
        out.writeInt(mData);
        out.writeString(mName);
        out.writeParcelable(mInfo, flags)
    }

    // Using the `in` variable, we can retrieve the values that 
    // we originally wrote into the `Parcel`.  This constructor is usually 
    // private so that only the `CREATOR` field can access.
    private MyParcelable(Parcel in) {
        mData = in.readInt();
        mName = in.readString();
        mInfo = in.readParcelable(MySubParcelable.class.getClassLoader());
    }

    public MyParcelable() {
        // Normal actions performed by class, since this is still a normal object!
    }

    // In the vast majority of cases you can simply return 0 for this.  
    // There are cases where you need to use the constant `CONTENTS_FILE_DESCRIPTOR`
    // But this is out of scope of this tutorial
    @Override
    public int describeContents() {
        return 0;
    }

    // After implementing the `Parcelable` interface, we need to create the 
    // `Parcelable.Creator<MyParcelable> CREATOR` constant for our class; 
    // Notice how it has our class specified as its type.  
    public static final Parcelable.Creator<MyParcelable> CREATOR
            = new Parcelable.Creator<MyParcelable>() {

        // This simply calls our new constructor (typically private) and 
        // passes along the unmarshalled `Parcel`, and then returns the new object!
        @Override
        public MyParcelable createFromParcel(Parcel in) {
            return new MyParcelable(in);
        }

        // We just need to copy this and change the type to match our class.
        @Override
        public MyParcelable[] newArray(int size) {
            return new MyParcelable[size];
        }
    };
}

READ HERE

The question was pretty clear. How to pass data between two different applications. Your case will work for two different activities. — vgokul129, Dec 08 '17 at 21:31

How to pass data both ways between different android applications?

6 Answers6

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