在服务器上运行时，Eclipse - Tomcat - java.lang.NoClassDefFoundError：javax / servlet / ServletConfig

Question

I'm fighting the whole day with this: I have DynamicWebProject. It worked fine. But at some point I desided to clean extra jar wich didn't used in project. After my cleaning, I've got a bunch of errors. So I rollback all my changes (I mean I retuned all jars back). But Also I played with Build Path of project, of Eclipse, of Debug config. Unfortunately I didn't remember this changes (with Path stuff). And when I run as at server, tomcat shows me this:

`

04.12.2012 16:37:43 org.apache.catalina.core.ApplicationContext log
SEVERE: StandardWrapper.Throwable
java.lang.NoClassDefFoundError: javax/servlet/ServletConfig
    at org.apache.axis2.deployment.WarBasedAxisConfigurator.<init>(WarBasedAxisConfigurator.java:103)
    at org.apache.axis2.transport.http.AxisServlet.initConfigContext(AxisServlet.java:584)
    at org.apache.axis2.transport.http.AxisServlet.init(AxisServlet.java:454)
    at org.apache.axis2.webapp.AxisAdminServlet.init(AxisAdminServlet.java:60)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1266)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1185)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
04.12.2012 16:37:43 org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /library threw load() exception
java.lang.NoClassDefFoundError: javax/servlet/ServletConfig
    at org.apache.axis2.deployment.WarBasedAxisConfigurator.<init>(WarBasedAxisConfigurator.java:103)
    at org.apache.axis2.transport.http.AxisServlet.initConfigContext(AxisServlet.java:584)
    at org.apache.axis2.transport.http.AxisServlet.init(AxisServlet.java:454)
    at org.apache.axis2.webapp.AxisAdminServlet.init(AxisAdminServlet.java:60)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1266)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1185)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1080)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5027)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
04.12.2012 16:37:43 org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
04.12.2012 16:37:43 org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-bio-8009"]
04.12.2012 16:37:43 org.apache.catalina.startup.Catalina start
INFO: Server startup in 3556 ms

`

I'm real tied with this endless fight. What I'm doing wrong? What Eclipse and Tomcat tries to tell me?

---

Done.

So. How I restore functionality. First of all, my project was backup in SVN repository. Next I create new Workspace in Eclipse. new workspace in different folder. And Checkout project from SVN. After that, at step - run at server, I caught errors, and added one by one missed libraries(jars). And whoa-la, it works! So how I thought, problem resides in configuration of eclipce and project, also in Run/Debug Configuration. How to find errors in configuration, I don't know :( but I'll try at old workspace.

Answer 1

You are missing servlet-api.jar in your class path. Check it

UPDATED

1) Right click on project
2) Got to java build path
3) Click on add library in right hand side.
4) Choose server run time.
5) Click next and select your tom cat server.
6) Click on finish.

Then try again

Answer 2

Go to the Java Build Path , go to Libraries , click on Add Library , choose Server Runtime , click Next , choose your webserver and click Finish. Clean and deploy to see if it works.