我有一个Google Appengine / Java设置，Restlet for appengine（2.0.11）。应用程序在部署时运行正常，但在尝试连接到本地的任何Restlet入口点时会抛出此错误（localhost）。完整的痕迹粘贴在下面。我在Mac上，使用GAE 1.6.1和Eclipse Helios。有什么想法可以纠正吗？
Feb 1, 2012 10:16:12 AM com.myapp.MyRestletServerResource retrieve
Feb 1, 2012 10:16:12 AM org.restlet.engine.http.adapter.ServerAdapter commit
SEVERE: An exception occured writing the response entity
java.lang.NoSuchMethodError: org.codehaus.jackson.type.JavaType.<init>(Ljava/lang/Class;)V
at org.codehaus.jackson.map.type.SimpleType.<init>(SimpleType.java:32)
at org.codehaus.jackson.map.type.TypeFactory._fromClass(TypeFactory.java:254)
at org.codehaus.jackson.map.type.TypeFactory._fromType(TypeFactory.java:266)
at org.codehaus.jackson.map.type.TypeFactory.type(TypeFactory.java:57)
at org.codehaus.jackson.map.ObjectMapper.<clinit>(ObjectMapper.java:49)
at org.restlet.ext.jackson.JacksonRepresentation.createObjectMapper(JacksonRepresentation.java:120)
at org.restlet.ext.jackson.JacksonRepresentation.getObjectMapper(JacksonRepresentation.java:164)
at org.restlet.ext.jackson.JacksonRepresentation.write(JacksonRepresentation.java:205)
at org.restlet.representation.WriterRepresentation.write(WriterRepresentation.java:104)
at org.restlet.engine.http.ServerCall.writeResponseBody(ServerCall.java:550)
at org.restlet.engine.http.ServerCall.sendResponse(ServerCall.java:488)
at org.restlet.ext.servlet.internal.ServletCall.sendResponse(ServletCall.java:492)
at org.restlet.engine.http.adapter.ServerAdapter.commit(ServerAdapter.java:197)
at org.restlet.engine.http.HttpServerHelper.handle(HttpServerHelper.java:151)
at org.restlet.ext.servlet.ServerServlet.service(ServerServlet.java:1028)
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$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
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:122)
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:78)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:362)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
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)
更新：我下载了最新版本的Jackson并替换了我正在使用的库，问题就消失了。