Michael, Easiest way to find out what's causing this is to open up the generated JSP file (not sure where this will be for you, it depends on the container you're using), go to line 78, and see what the code is doing. It's much easier than digging around in your JSP file trying to guess where you got the null pointer from. From there you'll be able to see exactly what variable/call is returning a null, and from there it should be easy to fix.
-Chris -----Original Message----- From: A mailing list about Java Server Pages specification and reference [mailto:[EMAIL PROTECTED]]On Behalf Of Michael Pomeroy Sent: Thursday, November 29, 2001 1:21 PM To: [EMAIL PROTECTED] Subject: Interesting Sort Problem I am adding sort functionality to a successful Results(Invoice2.jpg) page. I've created two drop-down list boxes to select the sort parameters: One with column names, the other sort order (ASC or DESC) I'm receiving a "Null Pointer Exception" error when I subit the sort. The URL generated by the code when the error occurs: http://localhost/jserv/Invoice2.jsp?order=Item&sort=ASC The page is in the "jserv" folder and is named: Invoice2.jsp ------------------------------------------ The error: 500 Internal Server Error /jserv/Invoice2.jsp: java.lang.NullPointerException at jrun__jserv__Invoice22ejsp13._jspService(jrun__jserv__Invoice22ejsp13.java:7 8) at allaire.jrun.jsp.HttpJSPServlet.service(../jsp/HttpJSPServlet.java:39) I am able to move to the Page with success, the fields are populated and I receive no errors. Then, when I perform the sort, I receive the above error. Here is my code: ---------------------------------------------------------------------------- --------------------- <%@page language="java" import="java.sql.*"%> <%@ include file="../Connections/connBeachwear.jsp" %> <% String rsBeachwear__varCheckbox = "1"; if (request.getParameter ("valueCheckbox") !=null) {rsBeachwear__varCheckbox = (String)request.getParameter ("valueCheckbox") ;} %> <% //NEW SORT VARIABLES: String rsBeachwear__name = "ID";//default sort value if (request.getParameter ("order") !=null) {rsBeachwear__name = (String)request.getParameter ("order");} %> <% String rsBeachwear__sort = "ASC";//default sort value if (request.getParameter ("sort") !=null) {rsBeachwear__sort = (String)request.getParameter ("sort");} %> <% Driver DriverrsBeachwear = (Driver)Class.forName(MM_connBeachwear_DRIVER).newInstance(); Connection ConnrsBeachwear = DriverManager.getConnection(MM_connBeachwear_STRING,MM_connBeachwear_USERNAM E,MM_connBeachwear_PASSWORD); String chkValues[]=request.getParameterValues("valueCheckbox"); StringBuffer prepStr=new StringBuffer("SELECT ID, Item, Color, Size FROM Beachwear WHERE ID="); for(int x=0;x<chkValues.length;++x){ prepStr.append( chkValues[x] ); if((x+1)<chkValues.length){//There will be another iteration prepStr.append(" OR ID="); }//end if }//end for loop //NEW SQL SORT CODE: prepStr.append(" ORDER BY '%" + rsBeachwear__name + "%' '%" + rsBeachwear__sort + "%'"); //Sample:("SELECT ID, Item, Color, Size FROM Beachwear WHERE Color LIKE '%" + rsBeachwear__varColor + "%' ORDER BY Item"); PreparedStatement StatementrsBeachwear=ConnrsBeachwear.prepareStatement(prepStr.toString()); ResultSet rsBeachwear = StatementrsBeachwear.executeQuery(); boolean rsBeachwear_isEmpty = !rsBeachwear.next(); boolean rsBeachwear_hasData = !rsBeachwear_isEmpty; Object rsBeachwear_data; int rsBeachwear_numRows = 0; %> <% int Repeat1__numRows = -1; int Repeat1__index = 0; rsBeachwear_numRows += Repeat1__numRows; %> <title>Beachwear Title</title> <body bgcolor="#FFFFFF"> <p> </p> <p> <p><br> INVOICE<br> </p> <%//FORM GET METHOD<%> <form name="form1" method="get" action="Invoice2.jsp"> <p><br> </p> <% while ((rsBeachwear_hasData)&&(Repeat1__numRows-- != 0)) { %> <table width="75%" border="1"> <tr> <td width="13%">ID:</td> <td width="87%"><%=(((rsBeachwear_data = rsBeachwear.getObject("ID"))==null || rsBeachwear.wasNull())?"":rsBeachwear_data)%></td> </tr> <tr> <td width="13%">ITEM:</td> <td width="87%"><%=(((rsBeachwear_data = rsBeachwear.getObject("Item"))==null || rsBeachwear.wasNull())?"":rsBeachwear_data)%></td> </tr> <tr> <td width="13%">COLOR:</td> <td width="87%"><%=(((rsBeachwear_data = rsBeachwear.getObject("Color"))==null || rsBeachwear.wasNull())?"":rsBeachwear_data)%></td> </tr> <tr> <td width="13%">SIZE:</td> <td width="87%"><%=(((rsBeachwear_data = rsBeachwear.getObject("Size"))==null || rsBeachwear.wasNull())?"":rsBeachwear_data)%></td> </tr> </table> <% Repeat1__index++; rsBeachwear_hasData = rsBeachwear.next(); } %> <p> </p> <br> <table width="21%" border="1"> <tr> <td width="30%"> <div align="center">Parameter</div> </td> <td width="17%"> <div align="center">1</div> </td> <td width="53%"> <div align="center">2</div> </td> </tr> <%//NEW PULL DOWN SORT LISTS %> <tr> <td width="30%"> <div align="center"> <input type="submit" value="Sort Now"> </div> </td> <td width="17%"> <div align="center"> <select name="order" size="1"> <option value="ID" selected>ID</option> <option value="Item">Item</option> <option value="Color">Color</option> <option value="Size">Size</option> </select> </div> </td> <td width="53%"> <div align="center"> <select name="sort" size="1"> <option value="ASC" selected>Ascending</option> <option value="DESC">Descending</option> </select> </div> </td> </tr> </table> </form> <% rsBeachwear.close(); ConnrsBeachwear.close(); %> =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant FAQs on JSP/Servlets can be found at: http://archives.java.sun.com/jsp-interest.html http://java.sun.com/products/jsp/faq.html http://www.esperanto.org.nz/jsp/jspfaq.jsp http://www.jguru.com/faq/index.jsp http://www.jspinsider.com
