Google plus Social API Integration (G+ Login in android)

Before Social login in android, first of all, you have to enable your app. 

Step 1:   To enable your app to get Google plus user profile, open following https://console.developers.google.com/cloud-resource-manager after that click on Create a New Project.

Step 2: install/update Google Play Services-

 In Android Studio, select Tools > Android > SDK Manager>SDK Tools and install or update the play services.

Step 3: Generating Google-Service.json File.

Now all the android projects which use Google APIs require a google-services.json file to be placed in the project’s app folder. Follow the below steps to get your google-services.json file.

-->  First of all, generate the SHA-1 fingerprint. Java key-tool can be used to generate the SHA-1 fingerprint. Open your terminal(cmd) and execute the following command to generate the SHA-1 fingerprint. If it asks for a password, type android, and press enter.

For windows follow the following command in java bin folder-

keytool -list -v -keystore "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

In My Project

First we open cmd --->cd C:\Program Files\Java\jdk-9.0.4\bin--->press enter --->after that write below command to generate SHA-1 fingerprints.

keytool -list -v -keystore "C:\Users\msclient009\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

Step 4: Go back following link https://developers.google.com/identity/sign-in/android/start-integrating click on Configure A Project.

After that Select or Create Project click on next select your platform Android and fill the required field and click on create.

Download Your Credentials (Google-service.json) file. After that copy the Google-service.json file and paste it into your project.

Step 5: Create Your Project

In your project's top-level build.gradle file adds the below code.

allprojects {
    repositories {
        google()
    }
}

Then, in your app-level build.gradle file, declare Google Play services as a dependency:

apply plugin: 'com.android.application'
    ...
    dependencies {
        compile 'com.google.android.gms:play-services-auth:15.0.1'
    }

Step 6:   Add the Google Sign in button in Your Project (main_activity.java).

<com.google.android.gms.common.SignInButton
 android:id="@+id/sign_in_button"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content" />

Add the below code in your MainActivity.java file.

mSignInOptions = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestEmail().build();
mGoogleApiClient = new GoogleApiClient.Builder(this)
        .enableAutoManage(this, this).addApi(Auth.GOOGLE_SIGN_IN_API, mSignInOptions).build();
Button signInButton = findViewById(R.id.sign_in_button);
signInButton.setOnClickListener(this);
@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.sign_in_button:
            signIn();
            break;
        // ...
    }
}
public void googleSignIn() {
   Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
   startActivityForResult(signInIntent, REQ_CODE_GOOGLE_SIGN_IN);
}
@Override
public void startActivityForResult(Intent intent, int requestCode) {
    intent.putExtra("requestCode", requestCode);
    super.startActivityForResult(intent, requestCode);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    Log.v("Request Code", String.valueOf(requestCode));
    if (requestCode == REQ_CODE_GOOGLE_SIGN_IN) {
        Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
        handleSignInResult(task);
    }
}
private void handleSignInResult(Task<GoogleSignInAccount> completedTask) {
     try {
        GoogleSignInAccount account = completedTask.getResult(ApiException.class);
         String name = account.getDisplayName();
         String firstName = "";
         String lastName = "";
         if (name != null) {
             int end = name.lastIndexOf(' ');
             if (end >= 0) {
                 firstName = name.substring(0, end);
                 lastName = name.substring(end + 1, name.length());
             }
         }
         Log.v(" Google Profile Name : ", firstName + lastName + account.getEmail() + account.getId());
         Toast.makeText(getApplicationContext(),"Google+ Login Successful",Toast.LENGTH_SHORT).show();
         loginApi("Google", account.getId(), firstName, lastName, account.getEmail());
     } catch (ApiException e) {
         Log.e("Google Plus Login : ", e.getMessage(), e);
         Log.w("Value", "signInResult:failed code=" + e.getStatusCode());
         Toast.makeText(this,"Login failure : "+ e.getStatusCode(), Toast.LENGTH_LONG).show();
     }
 }
public void loginApi(String provider, String providerId, String firstName, String lastName, String emailId) {
    LoginAsyncTask asyncTask = new LoginAsyncTask(getApplicationContext(), provider, providerId, firstName, lastName, emailId);
    asyncTask.delegate = this;
    asyncTask.execute();
}
@Override
public void ifSuccess(boolean check) {
    if (check) {
        loginProgress.setVisibility(View.GONE);
        try {
            String className = getIntent().getStringExtra("ClassName");
            if(className.equals("LoginRegisterFragment") || className.equals("UserActivity") || className.equals("RegisterActivity")) {
                Intent intent = new Intent(UserLoginActivity.this, UserActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
                intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
                startActivity(intent);
                finish();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        previousPage();
        finish();
    } else {
        loginProgress.setVisibility(View.GONE);
        loginSubmit.setClickable(true);
        Toast.makeText(this, "email or password is incorrect", Toast.LENGTH_SHORT).show();
    }
}

LoginAsyncTask.java

package com.example.msclient010.mindstickqna.AsyncTask;
import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;
import com.example.msclient010.mindstickqna.Interface.LoginCheck;
import com.example.msclient010.mindstickqna.Utils.SaveSharedPreference;
import com.example.msclient010.mindstickqna.Utils.ServiceProvider;
import org.json.JSONException;
import org.json.JSONObject;
import java.net.URL;
public class LoginAsyncTask extends AsyncTask<Void, Boolean, Boolean> {
    private String mEmail, mPassword;
   // private final String LOG_TAG = LoginAsyncTask.class.getSimpleName();
    private Context mContext;
    String provider, providerId, firstName, lastName;
    public LoginCheck delegate = null;
    public LoginAsyncTask(Context context, String email, String pass) {
        mContext = context;
        mEmail = email;
        mPassword = pass;
    }
    public LoginAsyncTask(Context mContext, String provider, String providerId, String firstName, String lastName, String emailId) {
        this.mContext = mContext;
        this.provider = provider;
        this.providerId = providerId;
        this.firstName = firstName;
        this.lastName = lastName;
        this.mEmail = emailId;
    }
    @Override
    public void onPreExecute() {
    }
    @Override
    protected Boolean doInBackground(Void... strings) {
        JSONObject postDataParams = new JSONObject();
        try {
            URL serviceUrl;
            String postData;
            if (provider == null) {
                serviceUrl = new URL(ServiceProvider.SIGNIN_ENDPOINT);
                postDataParams.put("EmailID", mEmail);
                postDataParams.put("Password",mPassword);
            } else {
                serviceUrl = new URL(ServiceProvider.SIGNIN_ENDPOINT_SOCIAL);
                postDataParams.put("EmailID", mEmail);
                postDataParams.put("Password",mPassword);
                postDataParams.put("FirstName", firstName);
                postDataParams.put("LastName", lastName);
                postDataParams.put("Provider", provider);
                postDataParams.put("ProviderId", providerId);
            }
            return parseJson(ServiceProvider.postMethod(postDataParams, serviceUrl));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    @Override
    public void onPostExecute(Boolean result) {
        delegate.ifSuccess(result);
        delegate.updatedContent(result, false);
    }
  public boolean parseJson(String response) {
        final Boolean success;
        JSONObject recentData = null;
        Log.v("Response", response);
        try {
            recentData = new JSONObject(response);
            success = recentData.getBoolean("IsSuccess");
            if (success) {
                String fname = null, lname = null;
                long userId = 0;
                JSONObject arrayResult = recentData.getJSONObject("Data");
                fname = arrayResult.getString("FirstName");
                lname = arrayResult.getString("LastName");
                userId = arrayResult.getLong("ID");
                Log.v("DATA", fname + lname + userId);
                SaveSharedPreference.setFirstName(mContext, fname);
                SaveSharedPreference.setLastName(mContext, lname);
                SaveSharedPreference.setUserId(mContext, String.valueOf(userId));
                SaveSharedPreference.setEmailId(mContext, mEmail);
                SaveSharedPreference.setPassword(mContext, mPassword);
                return true;
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return false;
    }
}

ServiceProvider.java

 public static String postMethod(JSONObject postDataParams, URL url){

        HttpURLConnection urlConnection = null;

        BufferedReader reader = null;

        StringBuffer sb = new StringBuffer("");

        try {

            Log.e("params", postDataParams.toString().replace("\\",""));

            urlConnection = (HttpURLConnection) url.openConnection();

            urlConnection.setRequestMethod("POST");

            urlConnection.setRequestProperty("Accept", "application/json");

            urlConnection.setRequestProperty("Content-Type", "application/json");

            urlConnection.setReadTimeout(800000);

            urlConnection.setConnectTimeout(800000);

            long unixTime = System.currentTimeMillis() / 1000L;

            String nonce = DataProvider.GenerateGUID();

            String postData = postDataParams.toString();

            Log.v("Login Data", postData);

            String encryptedPostData = Base64Provider.encode(DataProvider.aesEncrypt(postData.getBytes("UTF-8"), ServiceProvider.KEY_ENCRYPTION.getBytes("UTF-8")));

            String signatureRaw = ServiceProvider.APP_ID + "POST" + ServiceProvider.URLEncode(url.toString()) + String.valueOf(unixTime) + nonce + encryptedPostData;

            String signature = DataProvider.hmacEncrypt(ServiceProvider.API_KEY, signatureRaw);

            String headerValue = "amx " + ServiceProvider.APP_ID + ":" + signature + ":" + nonce + ":" + String.valueOf(unixTime);

            urlConnection.setRequestProperty("Authorization", headerValue);

            urlConnection.setDoOutput(true);

            Writer wr = new BufferedWriter(new OutputStreamWriter(urlConnection.getOutputStream(), "UTF-8")); 
            wr.write(postData); 
            wr.flush(); 
            wr.close(); 
            int responseCode = urlConnection.getResponseCode(); 
            if (responseCode == HttpsURLConnection.HTTP_OK) { 
                BufferedReader in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream())); 
                String line = ""; 
                while((line = in.readLine()) != null) { 
                    sb.append(line); 
                    break; 
                } 
                Log.v("JSON", sb.toString()); //JSON returned 
               in.close(); 
            } else { 
                Log.v("Some error", "in login" + String.valueOf(responseCode)); 
            } 
        } catch (Exception e) {e.printStackTrace(); 
        } 
       return sb.toString(); 
    }

"I hope this will help you". Thanks...!!!