这个问题怎么解决？

 Exception reportmessage An exception occurred processing JSP page /form/vender/index.jsp at line 53description The server encountered an internal error that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: An exception occurred processing JSP page /form/vender/index.jsp at line 5350:  <%
51:  String s="select * from vender";
52:  ResultSet rs=db.executeQuery(s);
53:     while(rs.next())
54:     {
55:     int id=rs.getInt(1);
56:     out.println("<tr><td>"+rs.getString(2)+"</td><td>"+rs.getString(3)+"</td><td>"+rs.getString(4)+"</td><td>"+rs.getString(5)+"</td><td>"+rs.getString(6)+"</td><td><a href='del.jsp?id="+id+"'>删除</a>&nbsp;<a href='edit.jsp?id="+id+"'>修改</a></td></tr>");
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:567)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:469)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root causejava.lang.NullPointerException
org.apache.jsp.form.vender.index_jsp._jspService(index_jsp.java:154)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:431)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.21 logs.Apache Tomcat/8.0.21