我正在尝试使用来自谷歌应用引擎的驱动器 API 访问谷歌驱动器文档。作为开始，我编写了 servlet 以使用以下代码访问授权代码等：
package vik.sakshum.sakshumweb.server.common;
import java.io.IOException;
import java.io.InputStream;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
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.oauth2.Oauth2;
import com.google.api.services.oauth2.model.Userinfo;
import com.google.gson.Gson;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
/**
* Abstract servlet that sets up credentials and provides some convenience
* methods.
*
* @author vicfryzel@google.com (Vic Fryzel)
* @author jbd@google.com (Burcu Dogan)
*/
@SuppressWarnings("serial")
public abstract class GoogleDriveAuth extends RemoteServiceServlet {
/**
* Default transportation layer for Google Apis Java client.
*/
protected static final HttpTransport TRANSPORT = new NetHttpTransport();
/**
* Default JSON factory for Google Apis Java client.
*/
protected static final JsonFactory JSON_FACTORY = new JacksonFactory();
/**
* Key to get/set userId from and to the session.
*/
public static final String KEY_SESSION_USERID = "user_id";
/**
* Default MIME type of files created or handled by DrEdit.
* This is also set in the Google APIs Console under the Drive SDK tab.
*/
public static final String DEFAULT_MIMETYPE = "text/plain";
/**
* Path component under war/ to locate client_secrets.json file.
*/
public static final String CLIENT_SECRETS_FILE_PATH
= "/WEB-INF/client_secrets.json";
/**
* A credential manager to get, set, delete credential objects.
*/
private CredentialManager credentialManager = null;
/**
* Initializes the Servlet.
*
@Override
public void init() throws ServletException {
super.init();
// init credential manager
// credentialManager = new CredentialManager(
// getClientSecrets(), TRANSPORT, JSON_FACTORY);
}*/
/**
* Dumps the given object as JSON and responds with given HTTP status code.
* @param resp Response object.
* @param code HTTP status code to respond with.
* @param obj An object to be dumped as JSON.
*/
protected void sendJson(HttpServletResponse resp, int code, Object obj) {
try {
// TODO(burcud): Initialize Gson instance for once.
resp.setContentType("application/json");
resp.getWriter().print(new Gson().toJson(obj).toString());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
/**
* Dumps the given object to JSON and responds with HTTP 200.
* @param resp Response object.
* @param obj An object to be dumped as JSON.
*/
protected void sendJson(HttpServletResponse resp, Object obj) {
sendJson(resp, 200, obj);
}
/**
* Responds with the given HTTP status code and message.
* @param resp Response object.
* @param code HTTP status code to respond with.
* @param message Message body.
*/
protected void sendError(HttpServletResponse resp, int code, String message) {
try {
resp.sendError(code, message);
} catch (IOException e) {
throw new RuntimeException(message);
}
}
/**
* Transforms a GoogleJsonResponseException to an HTTP response.
* @param resp Response object.
* @param e Exception object to transform.
*/
protected void sendGoogleJsonResponseError(HttpServletResponse resp,
GoogleJsonResponseException e) {
sendError(resp, e.getStatusCode(), e.getLocalizedMessage());
}
/**
* Redirects to OAuth2 consent page if user is not logged in.
* @param req Request object.
* @param resp Response object.
*/
protected void loginIfRequired(HttpServletRequest req,
HttpServletResponse resp) {
Credential credential = getCredential(req, resp);
if (credential == null) {
// redirect to authorization url
try {
resp.sendRedirect(credentialManager.getAuthorizationUrl());
} catch (IOException e) {
throw new RuntimeException("Can't redirect to auth page");
}
}
}
/**
* If OAuth2 redirect callback is invoked and there is a code query param,
* retrieve user credentials and profile. Then, redirect to the home page.
* @param req Request object.
* @param resp Response object.
* @throws IOException
*/
protected void handleCallbackIfRequired(HttpServletRequest req,
HttpServletResponse resp) throws IOException {
String code = req.getParameter("code");
System.out.println("Code is:" + code);
if (code != null) {
// retrieve new credentials with code
Credential credential = credentialManager.retrieve(code);
// request userinfo
Oauth2 service = getOauth2Service(credential);
try {
Userinfo about = service.userinfo().get().execute();
String id = about.getId();
credentialManager.save(id, credential);
req.getSession().setAttribute(KEY_SESSION_USERID, id);
System.out.println("vik:: accessToken:" + credential.getAccessToken() + " refreshToken:" + credential.getRefreshToken());
} catch (IOException e) {
throw new RuntimeException("Can't handle the OAuth2 callback, " +
"make sure that code is valid.");
}
resp.sendRedirect("/");
}
}
@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException, ServletException {
System.out.println("start of GoogleDriveAuth:::::::");
credentialManager = new CredentialManager(
getClientSecrets(), TRANSPORT, JSON_FACTORY);
handleCallbackIfRequired(req, resp);
}
/**
* Returns the credentials of the user in the session. If user is not in the
* session, returns null.
* @param req Request object.
* @param resp Response object.
* @return Credential object of the user in session or null.
*/
protected Credential getCredential(HttpServletRequest req,
HttpServletResponse resp) {
String userId = (String) req.getSession().getAttribute(KEY_SESSION_USERID);
if (userId != null) {
return credentialManager.get(userId);
}
return null;
}
/**
* Deletes the credentials of the user in the session permanently and removes
* the user from the session.
* @param req Request object.
* @param resp Response object.
*/
protected void deleteCredential(HttpServletRequest req,
HttpServletResponse resp) {
String userId = (String) req.getSession().getAttribute(KEY_SESSION_USERID);
if (userId != null) {
credentialManager.delete(userId);
req.getSession().removeAttribute(KEY_SESSION_USERID);
}
}
/**
* Build and return a Drive service object based on given request parameters.
* @param credential User credentials.
* @return Drive service object that is ready to make requests, or null if
* there was a problem.
*/
protected Drive getDriveService(Credential credential) {
return new Drive.Builder(TRANSPORT, JSON_FACTORY, credential).build();
}
/**
* Build and return an Oauth2 service object based on given request parameters.
* @param credential User credentials.
* @return Drive service object that is ready to make requests, or null if
* there was a problem.
*/
protected Oauth2 getOauth2Service(Credential credential) {
return new Oauth2.Builder(TRANSPORT, JSON_FACTORY, credential).build();
}
/**
* Reads client_secrets.json and creates a GoogleClientSecrets object.
* @return A GoogleClientsSecrets object.
*/
private GoogleClientSecrets getClientSecrets() {
// TODO: do not read on each request
InputStream stream =
getServletContext().getResourceAsStream(CLIENT_SECRETS_FILE_PATH);
try {
return GoogleClientSecrets.load(JSON_FACTORY, stream);
} catch (IOException e) {
throw new RuntimeException("No client_secrets.json found");
}
}
}
在调用 servlet 时，我在日志中看到以下错误：
javax.servlet.ServletContext log: unavailable
java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at java.lang.Class.newInstance0(Class.java:370)
at java.lang.Class.newInstance(Class.java:323)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.appstats.AppstatsFilter.doFilter(AppstatsFilter.java:141)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:57)
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 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.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:266)
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$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:439)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:483)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:490)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:777)
at com.google.tracing.TraceContext$DoInTraceContext.runInContext(TraceContext.java:754)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:345)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:337)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:487)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:722)
W2013-06-18 18:26:57.398
/GoogleOauth
java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at java.lang.Class.newInstance0(Class.java:370)
at java.lang.Class.newInstance(Class.java:323)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.appstats.AppstatsFilter.doFilter(AppstatsFilter.java:141)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:57)
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 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.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:266)
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$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:439)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:483)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:490)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:777)
at com.google.tracing.TraceContext$DoInTraceContext.runInContext(TraceContext.java:754)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:345)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:337)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:487)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:722)
C2013-06-18 18:26:57.478
Uncaught exception from servlet
java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(InstantiationExceptionConstructorAccessorImpl.java:48)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at java.lang.Class.newInstance0(Class.java:370)
at java.lang.Class.newInstance(Class.java:323)
at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.appstats.AppstatsFilter.doFilter(AppstatsFilter.java:141)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:57)
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 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.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:266)
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$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:439)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:483)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:490)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:777)
at com.google.tracing.TraceContext$DoInTraceContext.runInContext(TraceContext.java:754)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:345)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:337)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:487)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:722)