io.mapping.api.billsplit.resources.ConnectGoogleResource.java Source code

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Here is the source code for io.mapping.api.billsplit.resources.ConnectGoogleResource.java

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/*
 * Copyright 2013 Jacob Miles Prystowsky
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.mapping.api.billsplit.resources;

import com.google.api.client.auth.oauth2.TokenResponseException;
import com.google.api.client.googleapis.auth.oauth2.*;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import io.mapping.api.billsplit.exceptions.InvalidOAuthStateException;
import io.mapping.api.billsplit.exceptions.NullOAuthCodeException;
import io.mapping.api.billsplit.oauth2.OAuth2Helper;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import java.io.*;
import java.security.GeneralSecurityException;

import static io.mapping.api.billsplit.exceptions.GenericOAuthTokenErrorException.Builder;
import static io.mapping.api.billsplit.exceptions.GenericOAuthTokenErrorException.Messages;

@Path("/connect")
@Singleton
public class ConnectGoogleResource {
    private static final String GOOGLE_REDIRECT_URI = "postmessage";

    @Inject
    private OAuth2Helper mOAuth2Helper;

    @Inject
    private HttpTransport mHttpTransport;
    @Inject
    private JacksonFactory mJacksonFactory;
    @Inject
    private GoogleClientSecrets mGoogleClientSecrets;

    @POST
    @Path("google")
    @Produces(MediaType.APPLICATION_JSON)
    public GoogleTokenResponse connectGoogle(@Context HttpServletRequest request,
            @Context HttpServletResponse response, @QueryParam("state") final String state) throws IOException {
        // Check to see if they're already connected
        String token = mOAuth2Helper.getToken(request);
        if (token != null) {
            return mOAuth2Helper.parseGoogleToken(token);
        }

        // Allow forcing state
        if (state != null) {
            mOAuth2Helper.setState(request, state);
        }

        // Ensure the state parameter matches up
        if (!mOAuth2Helper.checkState(request, response)) {
            throw new InvalidOAuthStateException(500);
        }

        // Get the authorization code
        ByteArrayOutputStream resultStream = new ByteArrayOutputStream();
        getContent(request.getInputStream(), resultStream);
        String code = new String(resultStream.toByteArray(), "UTF-8");
        if (code == null) {
            throw new NullOAuthCodeException(500);
        }

        // Upgrade the authorization code into an access token and refresh token
        GoogleTokenResponse tokenResponse;
        try {
            tokenResponse = new GoogleAuthorizationCodeTokenRequest(mHttpTransport, mJacksonFactory,
                    mGoogleClientSecrets.getWeb().getClientId(), mGoogleClientSecrets.getWeb().getClientSecret(),
                    code, GOOGLE_REDIRECT_URI).execute();
        } catch (TokenResponseException ex) {
            throw new Builder(500).message(ex.getMessage()).build();
        }

        // Parse out the Google+ ID
        GoogleIdToken idToken = tokenResponse.parseIdToken();
        String userId = idToken.getPayload().getSubject();

        // Verify the token
        boolean verified = false;
        try {
            verified = new GoogleIdTokenVerifier.Builder(mHttpTransport, mJacksonFactory).build().verify(idToken);
        } catch (GeneralSecurityException e) {
            throw new Builder(500).message(e.getMessage()).build();
        }

        if (!verified) {
            throw new Builder(500).message(Messages.TOKEN_VERIFICATION_FAILED).build();
        }

        // Create a credential representation of the token data
        GoogleCredential credential = mOAuth2Helper.getGoogleCredential(tokenResponse);

        // Check token validity
        mOAuth2Helper.checkGoogleTokenValidity(credential, userId);

        // Store the token for next time
        mOAuth2Helper.setToken(request, mJacksonFactory.toString(tokenResponse));

        return tokenResponse;
    }

    /**
     * Read the content of an InputStream.
     *
     * @param inputStream the InputStream to be read.
     * @return the content of the InputStream as a ByteArrayOutputStream.
     * @throws IOException
     */
    static void getContent(InputStream inputStream, ByteArrayOutputStream outputStream) throws IOException {
        // Read the response into a buffered stream
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        int readChar;
        while ((readChar = reader.read()) != -1) {
            outputStream.write(readChar);
        }
        reader.close();
    }
}