HTTP Status 500 帮忙解决下t_t

Tomcat 6  JDK1.5 SUSE10 SERVICE
HTTP Status 500 -type Exception reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
com.thunis.portal.filter.SecureFilter.doFilter(SecureFilter.java:67)
com.thunis.portal.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:50)
root causejava.lang.NullPointerException
com.thunis.portal.ejb.PropsUtil.get(PropsUtil.java:180)
org.apache.jsp.login_jsp._jspService(login_jsp.java:161)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:390)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
com.thunis.portal.filter.SecureFilter.doFilter(SecureFilter.java:67)
com.thunis.portal.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:50)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.7 logs.