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javagwtcomet

GWT-comet build fails with ClassNotFoundException


I've tried to setup GWT-comet using the official guide(http://code.google.com/p/gwt-comet/wiki/GettingStarted). What I did:

  1. Add gwt-comet-1.2.3.jar to project and build path.
  2. Setup the basic client and server code.
  3. Inherit the required module.

< inherits name='net.zschech.gwt.comet.Comet'/>

The crash is obviously related to the inheriting the module. Stack trace:

Loading modules
   com.MyApp.Test
      Loading inherited module 'com.MyApp.Test'
         Loading inherited module 'net.zschech.gwt.comet.Comet'
            [ERROR] Unexpected error while processing XML
java.lang.NoClassDefFoundError: com/google/gwt/core/ext/GeneratorExt
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at com.google.gwt.dev.cfg.ModuleDefSchema$ClassAttrCvt.convertToArg(ModuleDefSchema.java:888)
    at com.google.gwt.dev.util.xml.HandlerArgs.convertToArg(HandlerArgs.java:64)
    at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:221)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294)
    at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68)
    at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:333)
    at com.google.gwt.dev.cfg.ModuleDefSchema$BodySchema.__inherits_begin(ModuleDefSchema.java:497)
    at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:230)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294)
    at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
    at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68)
    at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:333)
    at com.google.gwt.dev.cfg.ModuleDefLoader.load(ModuleDefLoader.java:254)
    at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:197)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromResources(ModuleDefLoader.java:157)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:132)
    at com.google.gwt.dev.DevModeBase.loadModule(DevModeBase.java:1026)
    at com.google.gwt.dev.DevMode.loadModule(DevMode.java:570)
    at com.google.gwt.dev.DevMode.doStartup(DevMode.java:456)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1094)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
Caused by: java.lang.ClassNotFoundException: com.google.gwt.core.ext.GeneratorExt
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 59 more
         [ERROR] Line 11: Unexpected exception while processing element 'inherits'
com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:336)
    at com.google.gwt.dev.cfg.ModuleDefSchema$BodySchema.__inherits_begin(ModuleDefSchema.java:497)
    at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:230)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294)
    at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
    at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68)
    at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:333)
    at com.google.gwt.dev.cfg.ModuleDefLoader.load(ModuleDefLoader.java:254)
    at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:197)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromResources(ModuleDefLoader.java:157)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:132)
    at com.google.gwt.dev.DevModeBase.loadModule(DevModeBase.java:1026)
    at com.google.gwt.dev.DevMode.loadModule(DevMode.java:570)
    at com.google.gwt.dev.DevMode.doStartup(DevMode.java:456)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1094)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
         [ERROR] Failure while parsing XML
com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries)
    at com.google.gwt.dev.util.xml.DefaultSchema.onHandlerException(DefaultSchema.java:58)
    at com.google.gwt.dev.util.xml.Schema.onHandlerException(Schema.java:66)
    at com.google.gwt.dev.util.xml.Schema.onHandlerException(Schema.java:66)
    at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:240)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294)
    at org.apache.xerces.parsers.AbstractSAXParser.startElement(Unknown Source)
    at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanStartElement(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
    at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
    at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
    at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
    at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68)
    at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:333)
    at com.google.gwt.dev.cfg.ModuleDefLoader.load(ModuleDefLoader.java:254)
    at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:197)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromResources(ModuleDefLoader.java:157)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:132)
    at com.google.gwt.dev.DevModeBase.loadModule(DevModeBase.java:1026)
    at com.google.gwt.dev.DevMode.loadModule(DevMode.java:570)
    at com.google.gwt.dev.DevMode.doStartup(DevMode.java:456)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1094)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
         [ERROR] Unexpected error while processing XML
com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:371)
    at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68)
    at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418)
    at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:333)
    at com.google.gwt.dev.cfg.ModuleDefLoader.load(ModuleDefLoader.java:254)
    at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:197)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromResources(ModuleDefLoader.java:157)
    at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:132)
    at com.google.gwt.dev.DevModeBase.loadModule(DevModeBase.java:1026)
    at com.google.gwt.dev.DevMode.loadModule(DevMode.java:570)
    at com.google.gwt.dev.DevMode.doStartup(DevMode.java:456)
    at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1094)
    at com.google.gwt.dev.DevModeBase.run(DevModeBase.java:844)
    at com.google.gwt.dev.DevMode.main(DevMode.java:322)
[ERROR] shell failed in doStartup method

Any idea why this occurs? Thanks in advance.


Solution

  • The gwt-comet-1.2.3.jar is not compatible with GWT 2.5.0-rc1 (or higher).

    so you need to upgrade the gwt-comet version to 1.2.5.

    link : https://gwt-comet.googlecode.com/issues/attachment?aid=330005000&name=gwt-comet-1.2.5.jar&token=St1Wda3HoyBJfRyZZ-Vq3zQibKo%3A1398940143165