HTTP Status 500 - net.sf.json.JSONException: null object

type Exception report

message net.sf.json.JSONException: null object

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: net.sf.json.JSONException: null object
	org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535)
	org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433)
	org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
	org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
	org.tuckey.web.filters.urlrewrite.RewrittenUrl.doRewrite(RewrittenUrl.java:176)
	org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:728)
	com.kbz.filter.SetEncodingFilter.doFilter(SetEncodingFilter.java:75)

root cause

net.sf.json.JSONException: null object
	net.sf.json.JSONObject.verifyIsNull(JSONObject.java:2744)
	net.sf.json.JSONObject.getString(JSONObject.java:2087)
	com.hbksw.bll.NewsService.loadByService(NewsService.java:57)
	com.hbksw.action.CollegeAction.detail(CollegeAction.java:280)
	sun.reflect.GeneratedMethodAccessor51.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:606)
	org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:270)
	org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:187)
	org.springframework.web.struts.DelegatingActionProxy.execute(DelegatingActionProxy.java:110)
	org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
	org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
	org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
	org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
	org.tuckey.web.filters.urlrewrite.RewrittenUrl.doRewrite(RewrittenUrl.java:176)
	org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:728)
	com.kbz.filter.SetEncodingFilter.doFilter(SetEncodingFilter.java:75)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.37 logs.