OAuth2.0 の アクセストークンを Google から取得する方法

<?xml version="1.0" encoding="UTF-8"?>
<oauth-provider-config xmlns="http://www.intra-mart.jp/system/oauth/client/config/oauth-provider-config"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.intra-mart.jp/system/oauth/client/config/oauth-provider-config ../schema/oauth-provider-config.xsd ">

  <oauth-providers>

    <oauth-provider id="im_cookbook_113639_oauth_client_google">
      <provider-type>google</provider-type>

      <name message-cd="CAP.Z.IWP.GOOGLE.OAUTH.PROVIDER.NAME">Google Drive™ API - im_cookbook_113639</name>
      <description message-cd="CAP.Z.IWP.GOOGLE.OAUTH.PROVIDER.DESCRIPTION">It is allow the use of the Google's Drive API.</description>
      <icon-path>im_cookbook_113639_oauth_client_google/images/google-drive-icon_48.png</icon-path>
      <oauth-config>
        <authz-end-point>https://accounts.google.com/o/oauth2/auth</authz-end-point>
        <token-end-point>https://accounts.google.com/o/oauth2/token</token-end-point>

        <client-id>[Please input your application's Client ID]</client-id>
        <client-secret>[Please input your application's Client Secret]</client-secret>
        <scope>https://www.googleapis.com/auth/drive.readonly https://www.googleapis.com/auth/drive.metadata.readonly https://www.googleapis.com/auth/drive.photos.readonly</scope>

      </oauth-config>
      <extra-config>
      </extra-config>
    </oauth-provider>

  </oauth-providers>

</oauth-provider-config>

public class GoogleAuthzCodeRequest extends AuthzCodeRequest {

    public GoogleAuthzCodeRequest(final String providerId, final OAuthConnectionInfo connectionInfo) {
        super(providerId, connectionInfo);

        addParameter(GoogleConstants.PARAM_NAME_4_ACCESS_TYPE, "offline");
        addParameter(GoogleConstants.PARAM_NAME_4_APPROVAL_PROMPT, "force");
    }

}

public final class GoogleConstants {

    public static final String PROVIDER_TYPE = "google"; //$NON-NLS-1$

    public static final String PARAM_NAME_4_ACCESS_TYPE = "access_type"; //$NON-NLS-1$

    public static final String PARAM_NAME_4_APPROVAL_PROMPT = "approval_prompt"; //$NON-NLS-1$

    private GoogleConstants() {
    }

}

public class RefreshAccessTokenRequestProcessorWithoutRefreshTokenOnSuccessResponse extends AbstractRefreshAccessTokenRequestProcessor {

    private final ThreadLocal previousRefreshTokens = new ThreadLocal();

    protected RefreshAccessTokenRequestProcessorWithoutRefreshTokenOnSuccessResponse(final String providerType) {
        super(providerType);
    }

    @Override
    protected RefreshTokenRequest createRequest(final String providerId, final String refreshToken) throws OAuthClientException {
        previousRefreshTokens.set(refreshToken);
        return super.createRequest(providerId, refreshToken);
    }

    @Override
    protected AccessTokenInfo parseResponse(final String providerId, final ResponseModel<HttpEntityModel> response) throws OAuthClientException, OAuthRequestException {
        try {
            final AccessTokenInfo accessTokenInfo = super.parseResponse(providerId, response);
            final String refreshTokenOnResponse = accessTokenInfo.getRefreshToken();

            // アクセストークン更新時の成功レスポンスに refresh_token が含まれていない場合は、以前のリフレッシュトークンを再利用する。
            if (refreshTokenOnResponse == null || refreshTokenOnResponse.isEmpty()) {
                accessTokenInfo.setRefreshToken(previousRefreshTokens.get());
            }

            return accessTokenInfo;
        } finally {
            previousRefreshTokens.remove();
        }
    }

    @Override
    protected void validateToken(final AccessTokenInfo tokenInfo) throws OAuthResponseParseException {
        try {
            super.validateToken(tokenInfo);
        } catch (final OAuthResponseParseException e) {
            // アクセストークン更新時の成功レスポンスに refresh_token が含まれていない場合、エラーとしない。
            if (e.getMessage().contains(OAuthClientLog.E_IWP_OAUTHCLIENT_PROCESSOR_00016.getWithCode())) {
                return;
            } else {
                throw e;
            }
        }
    }

}

jp.co.intra_mart.cookbook.im_cookbook_113639.oauth.client.service.processor.impl.GoogleOAuthRequestProcessorFactory

public class GoogleOAuthRequestProcessorFactory extends StandardOAuthRequestProcessorFactory {

    private final OAuthAuthzCodeRequestProcessor authzCodeProcessor;

    private final OAuthRefreshAccessTokenRequestProcessor refreshTokneProcessor;

    public GoogleOAuthRequestProcessorFactory() {
        authzCodeProcessor = new GoogleAuthzCodeRequestProcessor();

        // Googleの場合、アクセストークン更新時の成功レスポンスには refresh_token が含まれない（2016年4月現在）
        refreshTokneProcessor = new RefreshAccessTokenRequestProcessorWithoutRefreshTokenOnSuccessResponse(GoogleConstants.PROVIDER_TYPE);
    }

    @Override
    public OAuthAuthzCodeRequestProcessor getAuthzCodeRequestProcessor() {
        return authzCodeProcessor;
    }

    @Override
    public String getProviderType() {
        return GoogleConstants.PROVIDER_TYPE;
    }

    @Override
    public OAuthRefreshAccessTokenRequestProcessor getRefreshAccessTokenRequestProcessor() {
        return refreshTokneProcessor;
    }

}

public class GoogleAuthzCodeRequestProcessor extends AbstractAuthzCodeRequestProcessor {

    public GoogleAuthzCodeRequestProcessor() {
        super(GoogleConstants.PROVIDER_TYPE);
    }

    @Override
    protected AuthzCodeRequest createRequestInstance(final String providerId) throws OAuthClientException {
        final OAuthConnectionInfo connectionInfo = OAuthProviderConfigurationFactory.getInstance().getConnectionInfoAccessor().getConnectionInfo(providerId);
        return new GoogleAuthzCodeRequest(providerId, connectionInfo);
    }

}

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>

<%@ page import="java.util.LinkedHashMap"%>
<%@ page import="java.util.Map"%>

<%@ page import="jp.co.intra_mart.cookbook.im_cookbook_113639.oauth.client.service.processor.impl.GoogleConstants"%>

<%@ page import="jp.co.intra_mart.foundation.context.Contexts"%>
<%@ page import="jp.co.intra_mart.foundation.context.model.AccountContext"%>
<%@ page import="jp.co.intra_mart.foundation.oauth.client.model.AccessTokenInfo"%>
<%@ page import="jp.co.intra_mart.foundation.oauth.client.service.OAuthClientService"%>
<%@ page import="jp.co.intra_mart.foundation.oauth.client.service.OAuthClientServiceFactory"%>

<%@ page import="org.apache.commons.httpclient.Header"%>
<%@ page import="org.apache.commons.httpclient.HttpClient"%>
<%@ page import="org.apache.commons.httpclient.methods.GetMethod"%>

<%
final String uri = "https://www.googleapis.com/drive/v3/files";

final String userCd = Contexts.get(AccountContext.class).getUserCd();
final String providerId = "im_cookbook_113639_oauth_client_google";

final OAuthClientService oAuthClient = OAuthClientServiceFactory.getInstance().getOAuthClientService(GoogleConstants.PROVIDER_TYPE);
final AccessTokenInfo token = oAuthClient.getAccessToken(userCd, providerId);

int status;
Map responseHeaders;
String responseBodyAsString;

final GetMethod httpRequest = new GetMethod(uri);
try{
    httpRequest.addRequestHeader("Authorization", token.getTokenType() + " " + token.getAccessToken()); // <-- Set AccessToken
    httpRequest.addRequestHeader("Content-Type", "application/json; charset=UTF-8");
    httpRequest.addRequestHeader("Accept", "application/json");

    status = new HttpClient().executeMethod(httpRequest);

    responseHeaders = new LinkedHashMap();
    for (final Header header : httpRequest.getResponseHeaders()) {
        responseHeaders.put(header.getName(), header.getValue());
    }

    responseBodyAsString = httpRequest.getResponseBodyAsString();
} finally {
    httpRequest.releaseConnection();
}

%>

<table border="1">
    <tr>
        <th>status</th>
        <td><%=status%></td>
    </tr>
    <tr>
        <th>responseHeaders</th>
        <td><pre><%=responseHeaders%></pre></td>
    </tr>
    <tr>
        <th>responseBodyAsString</th>
        <td><pre><%=responseBodyAsString%></pre></td>
    </tr>
</table>