NoClassDefFoundError BaseModelData

[chaby]

I try to use com.extjs.gxt.ui.client.widget.form.ComboBox, and when i start the google viewer i got an error message :

EVERE: [1251712084581000] javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
java.lang.NoClassDefFoundError: com/extjs/gxt/ui/client/data/BaseModelData
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
	at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:142)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:247)
	at com.google.gwt.user.server.rpc.SerializationPolicyLoader.loadFromStream(SerializationPolicyLoader.java:129)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.doGetSerializationPolicy(RemoteServiceServlet.java:234)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.getSerializationPolicy(RemoteServiceServlet.java:117)
	at com.google.gwt.user.server.rpc.impl.ServerSerializationStreamReader.prepareToRead(ServerSerializationStreamReader.java:429)
	at com.google.gwt.user.server.rpc.RPC.decodeRequest(RPC.java:234)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:164)
	at com.google.gwt.user.server.rpc.RemoteServiceServlet.doPost(RemoteServiceServlet.java:86)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:713)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:806)
	at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1093)
	at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
	at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:124)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1084)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)
	at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:712)
	at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
	at com.google.apphosting.utils.jetty.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:54)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
	at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:313)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:139)
	at org.mortbay.jetty.Server.handle(Server.java:313)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:506)
	at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:844)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:644)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:381)
	at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:396)
	at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:442)
Caused by: java.lang.ClassNotFoundException: com.extjs.gxt.ui.client.data.BaseModelData
	at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
	at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:142)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
	... 46 more

in my service i use a class : Pipeline extends BaseModelData, but i don't know why GWT can't import BaseModelData, the other GXT classes are well imported
any ideas?

[sven]

Yes, the GXT jar ist not on the server classpath.

[chaby]

thanks for the quick reply
I added the external jar in my web application classpath (it was already in the path by the default project classpath entry). But Nothing change...

[arkitekt]

I am facing the same issue; has it been resolved? any leads?

I have done the following tests:

1. Populate a List in an RPC service and call it from the Client; this throws the afore mentioned exception.

2. Poplulate the list from withing the Client Side; and it works perfectly fine!

here is the little method:

public List<UserModel> loadUsers(){

List<UserModel> users = new ArrayList<UserModel>();
UserModel user = null;


for(int index = 0; index < 100; index++){

// create our dto
user = new UserModel();
user.setName("Name " + index);
user.setAge(index);

// create our child dto
AddressModel address = new AddressModel();
address.setStreet("Street " + index);
user.setAddress(address);

users.add(user);

}

return users;
}

[kaay]

Simple copy gxt.xml to you application web-inf/lib folder.