Google+ signin on Android

Question

I've been trying to integrate Google+ sign in functionality to my Android app and I get an internal error.

I have already tried the code on Android developer community but now i get this error "Internal error occured".

What have I missed here?

public class MainActivity extends Activity implements ConnectionCallbacks, OnConnectionFailedListener {
    private static final int RC_SIGN_IN = 0;

    private GoogleApiClient mGoogleApiClient;

    private boolean mIntentInProgress;

    private boolean mSignInClicked;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(Plus.API)
                .addScope(Plus.SCOPE_PLUS_LOGIN)
                .build();
        Button btnLogin = (Button) rootView.findViewById(R.id.btn_signin);
        btnLogin.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (view.getId() == R.id.sign_out_button) {
                    if (mGoogleApiClient.isConnected()) {
                        Plus.AccountApi.clearDefaultAccount(mGoogleApiClient);
                        mGoogleApiClient.disconnect();
                        mGoogleApiClient.connect();
                    }
                }

            }
        });
    }
    @Override
    protected void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }
    @Override
    protected void onStop() {
        super.onStop();

        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
    @Override
    public void onConnectionFailed(ConnectionResult result) {
        if (!mIntentInProgress) {
            if (mSignInClicked && result.hasResolution()) {
                // The user has already clicked 'sign-in' so we attempt to resolve all
                // errors until the user is signed in, or they cancel.
                try {
                    result.startResolutionForResult(this, RC_SIGN_IN);
                    mIntentInProgress = true;
                } catch (SendIntentException e) {
                    // The intent was canceled before it was sent.  Return to the default
                    // state and attempt to connect to get an updated ConnectionResult.
                    mIntentInProgress = false;
                    mGoogleApiClient.connect();
                }
            }
        }
    }
    @Override
    public void onConnected(Bundle connectionHint) {
        mSignInClicked = false;
        Toast.makeText(this, "User is connected!", Toast.LENGTH_LONG).show();
    }

    protected void onActivityResult(int requestCode, int responseCode, Intent intent) {
        if (requestCode == RC_SIGN_IN) {
            if (responseCode != RESULT_OK) {
                mSignInClicked = false;
            }

            mIntentInProgress = false;

            if (!mGoogleApiClient.isConnected()) {
                mGoogleApiClient.reconnect();
            }
        }
    }
}

Answer 1

For google plus login integration you not need to create api key.But you need to create one auth client for your app in google api console using your sha key and your package name.You can also create multiple auth client for your debug sha and release sha. Hope this will help you.