tomcat tomcat http status 500

Question

HTTPステータス 500 -type 例外レポートメッセージ説明 The server encountered an internal error () that prevented it from fulfilling this request.例外org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:522)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:73)原因java.lang.NullPointerException
org.apache.jsp.pages.EmpChangesList_jsp._jspService(EmpChangesList_jsp.java:200)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:73)注意 原因のすべてのスタックトレースは、Apache Tomcat/6.0.18のログに記録されています

Answer 1

不把代码贴上来人家是看不懂的、、、、、
java.lang.NullPointerException

Answer 2

<%
     Connection conn = null;
     Context ctx = null;
    DataSource ds = null;
     ResultSet rs = null;
     try{
     //データベースへ接続
      ctx = new InitialContext();
        ds = (DataSource)ctx.lookup("java:/comp/env/jdbc/postgres");
        conn = ds.getConnection();
        Statement stmt = conn.createStatement();
String sql="select * from T_StaffHistory where T_StaffHistory.staffNo='"+ staffNo +"' order by seqNo desc";
     rs = stmt.executeQuery(sql);
     while(rs.next()){
     out.print("<tr>");
     out.print("<td align=right width='10%'>" + rs.getString("postCode") + "</td>");
     out.print("<td align=right width='15%'>" + rs.getString("dutyKind") + "</td>");
     out.print("<td align=right width='12%'>" + rs.getString("position") + "</td>");
     out.print("<td align=right width='10%'>" + rs.getString("payLevel") + "</td>");
     out.print("<td align=right width='10%'>" + rs.getString("baseWage") + "</td>");
     out.print("<td align=right width='10%'>" + rs.getString("changesDate") + "</td>");
     out.print("</tr>");
     }
     }catch(Exception e){
     }finally{
     conn.close();
     }
    %>