我已经与这个战斗了一个多月了，并且已经达到了我的结果。用例是这样的：
1 - 当我的客户为他的一个客户提供新文件时，他将其放在他的Google云端硬盘帐户的文件夹中。该文件夹与其客户共享。由于Google没有机制自动通知某人与他们共享的文件夹中的文件发生了变化，因此我必须编写一个。所以我有一个带有按钮的GAE / GWT应用程序Notify。该应用程序有一个扫描其客户端文件夹的按钮，如果该文件夹中有新文件，它会抓取该文件夹共享的人员的电子邮件地址，并向他们发送一封电子邮件，说明他们有新文件。
2 - 他需要定期向所有客户发送大量电子邮件。所以在他的仪表板上是第二个按钮，他格式化电子邮件并单击按钮，扫描仪转到所有客户端文件夹，并编译共享文件夹的所有人的列表。然后循环列表并发送电子邮件。
Drive SDK部分非常简单。直到我碰到了共享文件夹的人可用，而不是他们的电子邮件。因此，我开始尝试将较旧的API DocsService与Drive SDK结合使用，以便获取电子邮件地址。我通过示例应用程序进行了梳理，然后找到了一个实用程序类，它可以实现我想要的功能，在这里：
/ * *版权所有（c）2010 Google Inc. * *根据Apache许可证2.0版（“许可证”）获得许可;你可能不会使用这个文件，除了 *符合许可证。您可以在以下位置获取许可证副本 * * http://www.apache.org/licenses/LICENSE-2.0 * *除非适用法律要求或书面同意，否则根据许可证分发的软件 *按“原样”分发，不附带任何形式的保证或条件，快递 *或暗示。有关管理权限和限制的特定语言，请参阅许可证 *许可证。 * /
package com.voice.mailer.server;
import java.io.IOException;
import java.util.HashSet;
import java.util.logging.Logger;
import javax.servlet.http.HttpServletRequest;
import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.appengine.auth.oauth2.AppEngineCredentialStore;
import com.google.api.client.extensions.appengine.http.UrlFetchTransport;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson.JacksonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.appengine.api.users.UserServiceFactory;
import com.google.common.base.Preconditions;
import com.google.gdata.client.docs.DocsService;
/**
* Utility class for JDO persistence, OAuth flow helpers, and others.
*
* @author Yaniv Inbar
*/
class Utils {
/** Global instance of the HTTP transport. */
static final HttpTransport HTTP_TRANSPORT = new UrlFetchTransport();
static Credential credential = null;
/** Global instance of the JSON factory. */
static final JsonFactory JSON_FACTORY = new JacksonFactory();
private static GoogleClientSecrets clientSecrets = null;
private static final Logger log = Logger.getLogger(Utils.class.getName());
static GoogleClientSecrets getClientCredential() throws IOException {
if (clientSecrets == null) {
clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
Utils.class.getResourceAsStream("/client_secrets.json"));
Preconditions
.checkArgument(
!clientSecrets.getDetails().getClientId()
.startsWith("Enter ")
&& !clientSecrets.getDetails()
.getClientSecret()
.startsWith("Enter "),
"Download client_secrets.json file from https://code.google.com/apis/console/?api=calendar "
+ "into calendar-appengine-sample/src/main/resources/client_secrets.json");
}
return clientSecrets;
}
static String getRedirectUri(HttpServletRequest req) {
GenericUrl url = new GenericUrl(req.getRequestURL().toString());
url.setRawPath("/oauth2callback");
return url.build();
}
static GoogleAuthorizationCodeFlow newFlow() throws IOException {
HashSet<String> s = new HashSet<String>();
s.add(DriveScopes.DRIVE_FILE);
s.add("https://docs.google.com/feeds/");
s.add("https://docs.googleusercontent.com/");
s.add("https://spreadsheets.google.com/feeds/");
s.add("http://www.google.com/accounts/AuthSubRequest");
s.add("http://schemas.google.com/acl/2007");
s.add("https://www.googleapis.com/auth/userinfo");
return new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT,
JSON_FACTORY, getClientCredential(), s)
.setCredentialStore(new AppEngineCredentialStore())
.setAccessType("offline").build();
// http(s)://docs.google.com/feeds/
}
static Drive loadDriveClient() throws IOException {
if (credential == null) {
String userId = UserServiceFactory.getUserService()
.getCurrentUser().getUserId();
credential = newFlow().loadCredential(userId);
}
return new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential)
.build();
}
static DocsService loadDocsService(String applicationName) {
if (credential == null) {
String userId = UserServiceFactory.getUserService()
.getCurrentUser().getUserId();
try {
credential = newFlow().loadCredential(userId);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
DocsService service = new DocsService(applicationName);
log.info("token: " + credential.getAccessToken());
service.setOAuth2Credentials(credential);
// service.setHeader("Authorization",
// "Bearer " + credential.getAccessToken());
return service;
}
/**
* Returns an {@link IOException} (but not a subclass) in order to work
* around restrictive GWT serialization policy.
*/
static IOException wrappedIOException(IOException e) {
if (e.getClass() == IOException.class) {
return e;
}
return new IOException(e.getMessage());
}
private Utils() {
}
}
现在这个类处理Drive SDK部分很棒，我能够调用loadDriveClient方法，并且我得到了一个准备好摇滚的类。但是当我调用loadDocsService并调用方法时，我不断收到以下错误：
10, 2013 5:36:07 PM com.google.appengine.repackaged.org.apache.http.impl.client.DefaultRequestDirector handleResponse
WARNING: Authentication error: Unable to respond to any of these challenges: {authsub=WWW-Authenticate: AuthSub realm="http://www.google.com/accounts/AuthSubRequest"}
com.google.gdata.client.GoogleService$SessionExpiredException: OK
<HTML>
<HEAD>
<TITLE>Token invalid - AuthSub token has wrong scope</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Token invalid - AuthSub token has wrong scope</H1>
<H2>Error 401</H2>
</BODY>
</HTML>
at com.google.gdata.client.http.GoogleGDataRequest.handleErrorResponse(GoogleGDataRequest.java:570)
at com.google.gdata.client.http.HttpGDataRequest.checkResponse(HttpGDataRequest.java:560)
at com.google.gdata.client.http.HttpGDataRequest.execute(HttpGDataRequest.java:538)
at com.google.gdata.client.http.GoogleGDataRequest.execute(GoogleGDataRequest.java:536)
at com.google.gdata.client.Service.getFeed(Service.java:1135)
at com.google.gdata.client.Service.getFeed(Service.java:998)
at com.google.gdata.client.GoogleService.getFeed(GoogleService.java:652)
at com.google.gdata.client.Service.getFeed(Service.java:1017)
at com.voice.mailer.shared.DocumentList.getAclFeed(DocumentList.java:611)
at com.voice.mailer.server.NewFileProcessorImpl.processNewFiles(NewFileProcessorImpl.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:383)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Mar 10, 2013 5:36:21 PM com.google.appengine.api.datastore.dev.LocalDatastoreService$PersistDatastore persist
INFO: Time to persist datastore: 6 ms
我已经尝试了我能想到的一切以及我能找到的每一个例子。我不知道为什么它没有正确创建DocsService。你能否告诉我为什么这不起作用？
感谢