Errors when starting a GWT/Hibernate program - eclipse

Question

I am trying to make a simple web application that adds a user to a database. I am using GWT-RPC with Hibernate, MySQL, and Eclipse IDE, all on Windows 7. I learnt through a tutorial how to save/add/delete values in a database using Hibernate, as well as how to do GWT-RPC from a GWT tutorial. Now, I'm trying to merge the two in a very simple program.
When starting the application through Eclipse, I get the following errors:
[WARN] Server class 'org.hibernate.Session' could not be found in the web app, but was found on the system classpath
[WARN] Adding classpath entry 'file:/D:/enterprize/MyFirstHibernateApp/lib/hibernate3.jar' to the web app classpath for this session
For additional info see: file:/D:/Programs/eclipse/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.r37v201108301710/gwt-2.4.0/doc/helpInfo/webAppClassPath.html
[WARN] Server class 'org.dom4j.DocumentException' could not be found in the web app, but was found on the system classpath
[WARN] Adding classpath entry 'file:/D:/enterprize/MyFirstHibernateApp/lib/dom4j-1.6.1.jar' to the web app classpath for this session
For additional info see: file:/D:/Programs/eclipse/plugins/com.google.gwt.eclipse.sdkbundle_2.4.0.r37v201108301710/gwt-2.4.0/doc/helpInfo/webAppClassPath.html
Initial SessionFactory creation failed.java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory
Starting Jetty on port 8888
[WARN] Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String rpctest.client.RpctestService.addUser(java.lang.String,java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: java.lang.ExceptionInInitializerError
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.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
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:729)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.handler.RequestLogHandler.handle(RequestLogHandler.java:49)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:843)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:647)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:205)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
Caused by: java.lang.ExceptionInInitializerError
at hibDomain.HibernateUtil.buildSessionFactory(HibernateUtil.java:16)
at hibDomain.HibernateUtil.<clinit>(HibernateUtil.java:7)
at rpctest.server.RpctestServiceImpl.addUser(RpctestServiceImpl.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
... 22 more
Caused by: java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory
at org.hibernate.cfg.Configuration.<clinit>(Configuration.java:151)
at hibDomain.HibernateUtil.buildSessionFactory(HibernateUtil.java:11)
... 29 more
Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at com.google.gwt.dev.shell.jetty.JettyLauncher$WebAppContextWithReload$WebAppClassLoaderExtension.findClass(JettyLauncher.java:372)
at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:366)
at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:337)
... 31 more
[ERROR] 500 - POST /rpctest/testService (127.0.0.1) 57 bytes
Request headers
Accept: */*
X-GWT-Permutation: HostedMode
X-GWT-Module-Base: http://127.0.0.1:8888/rpctest/
Content-Type: text/x-gwt-rpc; charset=utf-8
Referer: http://127.0.0.1:8888/Rpctest.html?gwt.codesvr=127.0.0.1:9997
Accept-Language: en-us
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
Host: 127.0.0.1:8888
Content-Length: 168
Connection: Keep-Alive
Cache-Control: no-cache
Response headers
Content-Type: text/plain
From the last part of the stack trace, it appears that SLF4J library is somehow not visible. However, I clearly have the library in my path:
\lib\antlr-2.7.6.jar
\lib\commons-collections-3.1.jar
\lib\dom4j-1.6.1.jar
\lib\hibernate3.jar
\lib\hibernate-cglib-repack-2.1_3.jar
\lib\hibernate-entitymanager-4.0.0.CR5.jar
\lib\javassist-3.4.GA.jar
\lib\jta-1.1.jar
\lib\mysql-connector-java-5.1.18-bin.jar
\lib\slf4j-api-1.6.4.jar
\lib\slf4j-simple-1.6.4.jar

Answer 1

Make sure to put all the libraries in war/WEB-INF/lib. If you have them elsewhere, remove them from the classpath first, move them, then re-add them to the classpath.