Android SDK with vk

Android SDK

VK SDK allows you to authorize user without asking him to enter login/password. After that you can call any API methods.

Source code at GitHub

http://github.com/VKCOM/vk-android-sdk 

Prepare for Using VK SDK

To use VK SDK primarily you need to create a new VK application here by choosing the Standalone application type. Choose a title and confirm the action via SMS and you will be redirected to the application settings page.
You will require your Application ID (referenced as API_ID in the documentation). Fill in the "Batch name for Android", "Main Activity for Android" and "Certificate fingerprint for Android".

Certificate Fingerprint Receiving

To receive your certificate's fingerprint you can use one of the following methods.

Fingerprint Receiving via Keytool

1) You need to find the keystore location for your app. The debug store is usually located in these directories:

• ~/.android/ for OS X and Linux,
• C:\Documents and Settings\\.android\ for Windows XP,
• C:\Users\\.android\ for Windows Vista, Windows 7 and Windows 8.

The keystore for the release version is usually created by a programmer, so you should create it or recall its location.
2) After the keystore's location has been found, use keytool utilite (it is supplied with the Java SDK). You can get keys list with the following command:

keytool -exportcert -alias androiddebugkey -keystore path-to-debug-or-production-keystore -list -v

You will observe a similar result:
 

Certificate fingerprint: SHA1: DA:39:A3:EE:5E:6B:4B:0D:32:55:BF:EF:95:60:18:90:AF:D8:07:09

By deleting all the colons you'll get your key's fingerprint.

Fingerprint Receiveing via SDK

If you've already added SDK to your project, you can use the following function in each Activity of your app.

String[] fingerprints = VKUtil.getCertificateFingerprint(this, this.getPackageName()); 

As a rule, fingerprint contains a single line. It's a fingerprint of your certificate (depends on the certificate used for your app's signing)

You can add more than one fingerprint in your app settings, e.g., debug and release fingerprints.

Connecting VK SDK to Your Android Application

Connecting With Maven

You can add next maven dependency in your project:

com.vk:androidsdk:+

Connecting in Android Studio

We give preference to Android Studio and our platform is targeted firstly to this enviroment.

Connecting Using Gradle

You can add the library to your project using Gradle.
1) Copy the vksdk_library directory to your project's directory.
2) Find the settings.gradle file.

Most likely, it contains something like that:

include ':app'

Edit the line this way:

include ':vksdk_library',':app'

3)Now your project includes vksdk_library module. You need to add it like a dependency to your app. Find the build.gradle file in the subdirectory of your app's module (e.g., YOUR_PROJECT/app/build.gradle).

Add this line to the dependencies.

compile project(':vksdk_library')

Your file can be like that:

Connecting Without Gradle

If your project doesn't support Gradle, you can add SDK by the following way:

1. Open Project Settings and select Modules.
2. Click the Add (+) button and select Import module
3. Find the directory with VK SDK and select vksdk_library, click Add.
4. Select Create module from existing sources, then click Next two times. Rename the module from "main" to "vksdk", then click Next.
5. Add the new vksdk module as a dependency to your app's module.

Connecting Using Eclipse

1. In Package explorer click right mouse button, then click Import.
2. Select Android/Existing android code into workspace.
3. Find a folder with SDK, select vksdk_library.
4. In Properties of your app go to Android, add vksdk_library in the library section.

Editing AndroidManifest.xml

Your need to add to your manifest the following elements:
1) in the root of you need to add permission

2) in the element shoud be added

to avoid possible problems with running authorizing activity.

Using SDK

SDK Initialization

1) Add this to the resources file (example strings.xml)

YOUR_APP_ID 

2) Initialize the SDK on startup using the following method. The best way is to call it in the app's onCreate method.

VKSdk.initialize(Context applicationContext);

User Authorization

There are several authorization methods:

VkSdk.login(Activity runningActivity, String... scope);
VkSdk.login(Fragment runningFragment, String... scope); 

When succeeded call the onActivityResultMethod:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (!VKSdk.onActivityResult(requestCode, resultCode, data, new VKCallback() {
        @Override
        public void onResult(VKAccessToken res) {
            // User passed Authorization
        }
        @Override
        public void onError(VKError error) {
            // User didn't pass Authorization
        }
    })) {
        super.onActivityResult(requestCode, resultCode, data);
    }
}

Handling "AccessToken invalid"

Use AccessTokenTracker the following way:

public class Application extends android.app.Application {
    VkAccessTokenTracker vkAccessTokenTracker = new VkAccessTokenTracker() {
        @Override
        public void onVKAccessTokenChanged(VKAccessToken oldToken, VKAccessToken newToken) {
            if (newToken == null) {
                // VkAccessToken is invalid
            }
        }
    };
    @Override
    public void onCreate() {
        super.onCreate();
        vkAccessTokenTracker.startTracking();
        VKSdk.initialize(this);
    }
}

API Requests

Requests Syntax

1) Plain request.

VKRequest request = VKApi.users().get();

2) Request with parameters.

VKRequest request = VKApi.users().get(VKParameters.from(VKApiConst.USER_IDS, "1,2"));

3) Http (not https) request (only if scope VK_PER_NOHTTPS has been passed).

VKRequest request = VKApi.users().get(VKParameters.from(VKApiConst.USER_IDS, "1,2"));
request.secure = NO;

4) Request with predetermined maximum number of attempts.

VKRequest request = VKApi.wall().post(VKParameters.from(VKApiConst.OWNER_ID, "-60479154", VKApiConst.MESSAGE, "Привет, друзья!"));
request.attempts = 10;
//or infinite
//postReq.attempts = 0;

It will take 10 attempts until succeeds or an API error occurs.

5) Request that calls a method of VK API.

VKRequest request = new VKRequest("friends.get", VKParameters.from(VKApiConst.FIELDS, "sex,bdate,city"));

6) Request for uploading photos on user wall.

final Bitmap photo = getPhoto();
VKRequest request = VKApi.uploadWallPhotoRequest(new VKUploadImage(photo, VKImageParameters.jpgImage(0.9f)), 0, 60479154);

Requests Sending

request.executeWithListener(new VKRequestListener() {
    @Override
    public void onComplete(VKResponse response) {
        //Do complete stuff
    }
    @Override
    public void onError(VKError error) {
        //Do error stuff
    }
    @Override
    public void attemptFailed(VKRequest request, int attemptNumber, int totalAttempts) {
        //I don't really believe in progress
    }
}); 

Errors Handling

The VKError class contains the errorCode property. Compare its value with the global constant VKError.VK_API_ERROR. If it equals, process the apiError field that contains a description of a VK API error. Otherwise you should handle an http error in the httpError property.
Some errors (e.g., captcha error, validation error) can be proccessed by the SDK.

Batch Processing Requests

SDK gives a feature to execute several unrelated requests at the one call.
1) Prepare requests.

VKRequest request1 = VKApi.uploadWallPhotoRequest(new VKUploadImage(photo1, VKImageParameters.jpgImage(0.9f)), 0, 60479154);
VKRequest request2 = VKApi.uploadWallPhotoRequest(new VKUploadImage(photo2, VKImageParameters.jpgImage(0.5f)), 0, 60479154);
VKRequest request3 = VKApi.uploadWallPhotoRequest(new VKUploadImage(photo3, VKImageParameters.jpgImage(0.1f)), 0, 60479154);
VKRequest request4 = VKApi.uploadWallPhotoRequest(new VKUploadImage(photo4, VKImageParameters.pngImage()), 0, 60479154);

2) Combine created requests into one.

VKBatchRequest batch = new VKBatchRequest(request1, request2, request3, request4);

3) Load the obtained request.

batch.executeWithListener(new VKBatchRequestListener() {
                        @Override
                        public void onComplete(VKResponse[] responses) {
                            super.onComplete(responses);
                            String[] photos = new String[responses.length];
                            for (int i = 0; i < responses.length; i++) {
                                VKPhoto photoModel = ((VKPhotoArray) responses[i].parsedModel).get(0);
                                photos[i] = String.format("photo%s_%s", photoModel.owner_id, photoModel.id);
                            }
                            makePost(VKStringJoiner.join(photos, ","));
                        }
                        @Override
                        public void onError(VKError error) {
                            showError(error);
                        }
                    });

4) The result of each method returns to a corresponding requestListener. The batch VKResponse for each request in order they have been passed.