ClassNotFoundException的GWTBridge
即时通讯工作的一个GWT Web应用ClassNotFoundException的GWTBridge
和工作时就可以即时得到此异常,而试图从URL的XML文件中删除servlete。
我不知道很多有关GWT的underworkings,也许有人可以帮助我
这是代码从URL
public static String readURL(String path) throws IOException{
String data = "";
URL url = new URL(path);
URLConnection conn = url.openConnection();
BufferedReader br = new BufferedReader(new InputStreamReader(
conn.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
data += line;
}
br.close();
System.out.println(data.length());
return data;
}
获取数据,这是错误即时得到
SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract void com.cpsc310.sc2.client.RouteService.storeParsedData()' threw an unexpected exception: java.lang.NoClassDefFoundError: com/google/gwt/core/client/GWTBridge
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:389)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:579)
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$ApiProxyHandler.handle(JettyContainerService.java:409)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$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)
Caused by: java.lang.NoClassDefFoundError: com/google/gwt/core/client/GWTBridge
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at com.google.gwt.xml.client.impl.XMLParserImpl.<clinit>(XMLParserImpl.java:29)
at com.google.gwt.xml.client.XMLParser.<clinit>(XMLParser.java:28)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at com.cpsc310.sc2.server.parser.BikeRouteParser.parseRoutesbyDOM(BikeRouteParser.java:39)
at com.cpsc310.sc2.server.RouteServiceImpl.storeParsedData(RouteServiceImpl.java:93)
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)
... 38 more
Caused by: java.lang.ClassNotFoundException: com.google.gwt.core.client.GWTBridge
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:213)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
作为一般规则,你不能使用类是在一个client
包GWT客户端上下文之外(即服务器端)
(这是我们试图在全球范围内跨gwt-user.jar
适用的规则,也有一些例外,但他们大多是实施细节)
如果你想解析XML服务器上,使用javax.xml
,不。
我认为这样做的方法是建立一个服务,然后服务的接口将在客户端,而实现在服务器端。至少多数民众赞成他们是如何做到这一点在教程 – Pita 2013-03-17 04:32:57
一个接口是不同的,它不包含_code_。顺便说一句,很多人现在把他们的RPC接口放在一个'shared'包中。 – 2013-03-17 22:53:13
我发现我可以在共享实体的方法内实例化一个GWT类,但不能将它作为类的成员放置。只要你从客户端调用它就可以正常工作。 – slugmandrew 2013-10-28 16:39:52
添加下面的项目(确保包是正确的):
package com.google.gwt.core.client;
import com.google.gwt.core.shared.*;
/**
* Date: 1/17/13
* Time: 12:37 PM
* This class is used for fixing class not found com.google.gwt.core.client.GWTBridge;
*
* This is only needed for GXT 2 to work. Once we remove GXT2, this can be removed also.
*/
public abstract class GWTBridge extends com.google.gwt.core.shared.GWTBridge {
}
是在服务器端或客户端上运行的代码? – SteveP 2013-03-16 09:17:00
我粘贴的代码应该在服务器端调用 – Pita 2013-03-17 19:29:05