title: org.apache.jasper.JasperException: java.lang.NullPointerException
body: <p>i got this exception everytime i try to load my webapp:</p>
  
  <p>exception</p>
  
  <pre><code>org.apache.jasper.JasperException: java.lang.NullPointerException
  org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:538)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:370)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
  </code></pre>
  
  <p>root cause</p>
  
  <pre><code>java.lang.NullPointerException
  org.apache.jsp.index_jsp._jspInit(index_jsp.java:22)
  org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
  org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:164)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:340)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
  </code></pre>
  
  <p>how can i solve this exception?</p>