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)

来源

2013-03-16 Pita

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

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。

来源

2013-03-16 09:49:07

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 { 
}

原文： http://alexluca.com/2013/01/17/gwt-25-and-extgwt-224-classnotfoundexception-comgooglegwtcoreclientgwtbridge/

来源

2015-04-22 07:43:39

ClassNotFoundException的GWTBridge

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