SEVERE: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract com.orleans.project.shared.Agent com.orleans.project.client.GreetingService.connexion(java.lang.String,java.lang.String)' threw an unexpected exception: java.lang.NoClassDefFoundError: com/mysql/jdbc/exceptions/MySQLIntegrityConstraintViolationException
	at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
	at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
	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.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.NoClassDefFoundError: com/mysql/jdbc/exceptions/MySQLIntegrityConstraintViolationException
	at com.orleans.project.server.GreetingServiceImpl.connexion(GreetingServiceImpl.java:61)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
	... 17 more
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645)
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1491)
	... 23 more