title: java.lang.IllegalArgumentException: Document base [...] does not exist or is not a readable directory
body: <p>I'm getting the following error and I have no idea what it is, I'm new to servlets and tomcat server as well, so could you explain to me how do I identify errors such as the error below?. Any help is appreciated.</p>
  
  <pre><code>java.lang.IllegalArgumentException: Document base C: \Users\ agrosys\ workspace\.metadata\.plugins\ org.eclipse.wst.server.core\ tmp1\ wtpwebapps\ JqTree does not exist or is not a readable directory
      at org.apache.naming.resources.FileDirContext.setDocBase(FileDirContext.java: 136)
      at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java: 5145)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java: 5330)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java: 150)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java: 1575)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java: 1565)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  </code></pre>