Error “java.lang.ClassNotFoundException: com.ibm.icu.text.SimpleDateFormat” When Deploying GWT Application

Today i’ve met a very weird error when trying to deploy my GWT application to my tomcat 7,

SEVERE: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.util.List id.net.baculsoft.app.client.service. LoginService.getUtilDao(java.lang.String,java.util.Map)' 
threw an unexpected exception: java.lang.NoClassDefFoundError: com/ibm/icu/text/SimpleDateFormat
	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.RPC. invokeAndEncodeResponse(RPC.java:551)
	at org.gwtrpcspring.RemoteServiceDispatcher. invokeAndEncodeResponse(RemoteServiceDispatcher.java:57)
	at org.gwtrpcspring.RemoteServiceDispatcher. processCall(RemoteServiceDispatcher.java:38)
	at com.google.gwt.user.server.rpc. RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
	at com.google.gwt.user.server.rpc. AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)

which somehow, never happen on my development mode. After searching and trying various workarounds for several hours, i finally make it work by adding icu4j.jar. Well despite icu4j.jar’s size is more than 3mb, at least i’ve make my application running well. Thank God 😉