使用 1.17 rc 版本的 google api 客户端和服务，ClassDefFoundError每当我执行以下代码时，我都会得到一个：
Plus.Activities.Search req = service.activities().search(q);
ActivityFeed feed = req.execute();
堆栈跟踪：
Exception in thread "main" java.lang.NoClassDefFoundError: com/google/appengine/api/urlfetch/HTTPMethod
at com.google.api.client.extensions.appengine.http.UrlFetchTransport.buildRequest(UrlFetchTransport.java:125)
at com.google.api.client.extensions.appengine.http.UrlFetchTransport.buildRequest(UrlFetchTransport.java:51)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:863)
at com.google.api.client.auth.oauth2.TokenRequest.executeUnparsed(TokenRequest.java:283)
at com.google.api.client.auth.oauth2.TokenRequest.execute(TokenRequest.java:307)
at com.google.api.client.auth.oauth2.Credential.executeRefreshToken(Credential.java:570)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.executeRefreshToken(GoogleCredential.java:248)
at com.google.api.client.auth.oauth2.Credential.refreshToken(Credential.java:489)
at com.google.api.client.auth.oauth2.Credential.intercept(Credential.java:217)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:859)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:410)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:343)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:460)
at googleplus.GPGet.SearchActivities(GPGet.java:70)
at googleplus.GPGet.main(GPGet.java:53)
Caused by: java.lang.ClassNotFoundException: com.google.appengine.api.urlfetch.HTTPMethod
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
... 15 more