First of all, this is a forum for the GlassFish product but not for the
Tomcat product. So chance is low that Tomcat specific questions will get
answered in the same quality and quantity than it would be in a
dedicated Tomcat forum.
Second, please compile your code with "-g" (currently you instead seem
to have used "-g:none") and retry your test. Then, send the stack trace
again.
"edu.rice.rubis.servlets.ServletPrinter.printItemDescription(Unknown
Source)" will then be changed from "Unknown Source" to a file name and
line number. All you need to do then is to look at that line in that
file to found the cause. The cause is that in that line you are using
the dot operator ("."). In that line look at the word left of the dot.
That variable is null (uninitialized) in that moment (i. e. "item" or
"user" is null).
HTH
Markus
> -----Original Message-----
> From: arash_ [mailto:rezaei.arash_at_gmail.com]
> Sent: Sonntag, 27. September 2009 11:06
> To: users_at_glassfish.dev.java.net
> Subject: NullPointerException error
>
>
> Dear All, I am a totally newbie in java and trying to use an
> application. I
> had received the following error as the output of tomcat, could
someone
> please help me find out the origin of the error, I also presented here
> the
> code for "ServletPrinter.printItemDescription" and "PutBid.doGet"
after
> the
> error.
>
> -bash-3.2# 08:29:52,942 ERROR [PutBid]:260 - Servlet.service() for
> servlet
> PutBid threw exception
> java.lang.NullPointerException
> at
> edu.rice.rubis.servlets.ServletPrinter.printItemDescription(Unknown
> Source)
> at edu.rice.rubis.servlets.PutBid.doGet(Unknown Source)
> at
javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
> at
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
> at sun.reflect.GeneratedMethodAccessor63.invoke(Unknown
Source)
> at
>
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccesso
> rImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:585)
> at
> org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:244)
> at java.security.AccessController.doPrivileged(Native Method)
> at
javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
> at
>
org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:276
> )
> at
>
org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.ja
> va:162)
> at
>
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Applic
> ationFilterChain.java:262)
> at
>
org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationF
> ilterChain.java:52)
> at
>
org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilter
> Chain.java:171)
> at java.security.AccessController.doPrivileged(Native Method)
> at
>
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFil
> terChain.java:167)
> at
>
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperVal
> ve.java:213)
> at
>
org.apache.catalina.core.StandardContextValve.invoke(StandardContextVal
> ve.java:172)
> at
>
org.objectweb.jonas.web.catalina55.ResetAuthenticationValve.invoke(Rese
> tAuthenticationValve.java:107)
> at
>
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.jav
> a:127)
> at
>
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.jav
> a:117)
> at
>
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve
> .java:108)
> at
>
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:
> 174)
> at
>
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:8
> 75)
> at
>
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.pro
> cessConnection(Http11BaseProtocol
> .java:665)
> at
>
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoin
> t.java:528)
> at
>
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollo
> werWorkerThread.java:81)
> at
>
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPoo
> l.java:689)
> at java.lang.Thread.run(Thread.java:595)
> ------------------
> "ServletPrinter.printItemDescription":
> void printItemDescriptionToBuyNow(Item item, User user)
> {
> try
> {
> printHTMLheader("RUBiS: Buy Now");
> printHTMLHighlighted("You are ready to buy this item: " +
> item.getName());
>
> out.println(
> "<TABLE>\n"
> + "<TR><TD>Quantity<TD><BIG>"
> + item.getQuantity()
> + "</BIG>\n"
> + "<TR><TD>Seller<TD> \"/rubis/servlet/ViewUserInfo?userId="
> "
> + item.getSeller().getNickname()
> + " ( \"/rubis/servlet/PutCommentAuth?to=" Leave a comment
> on
> this user )\n"
> + "<TR><TD>Started<TD>"
> + item.getStartDate()
> + "\n"
> + "<TR><TD>Ends<TD>"
> + item.getEndDate()
> + "\n"
> + "</TABLE>");
>
> printHTMLHighlighted("Item description");
> out.println(item.getDescription());
> out.println("<br><p>\n");
>
> printHTMLHighlighted("Buy Now");
> printHTML(
> "<form action=\"/rubis/servlet/StoreBuyNow\" method=POST>\n"
> + "<input type=hidden name=userId value="
> + user.getId()
> + ">\n"
> + "<input type=hidden name=itemId value="
> + item.getId()
> + ">\n"
> + "<input type=hidden name=maxQty value="
> + item.getQuantity()
> + ">\n");
> if (item.getQuantity().intValue() > 1)
> printHTML(
> "<center><table><tr><td>Quantity:</td>\n"
> + "<td><input type=text size=5
> name=qty></td></tr></table></center>\n");
> else
> printHTML("<input type=hidden name=qty value=1>\n");
> printHTML("<p><center><input type=submit value=\"Buy
> now!\"></center><p>\n");
> }
> catch (Exception e)
> {
> out.println(
> "Unable to print Item description (exception: " + e +
> ")<br>\n");
> }
> }
> -----------------
> "PutBid.doGet"
> public void doGet(HttpServletRequest request, HttpServletResponse
> response)
> throws IOException, ServletException
> {
> ServletPrinter sp = null;
> Session sess = null;
> User user = null;
> Item item = null;
> Float maxBid = null;
> Integer nbOfBids = null;
>
> String itemStr = request.getParameter("itemId");
> String nick = request.getParameter("nickname");
> String pass = request.getParameter("password");
> sp = new ServletPrinter(response, "PutBid");
>
> if ((itemStr == null)
> || (itemStr.equals(""))
> || (nick == null)
> || (nick.equals(""))
> || (pass == null)
> || (pass.equals("")))
> {
> printError("Item id, name and password are required - Cannot
> process
> the request<br>", sp);
> return;
> }
>
> // Authenticate the user who want to bid
> sess = getSession();
> Auth auth = new Auth(sess, sp);
> user = auth.authenticate(nick, pass);
> if (user == null)
> {
> printError(" You don't have an account on RUBiS!<br>You have to
> register first.<br>", sp);
> releaseSession(sess);
> return;
> }
>
> // Try to find the Item corresponding to the Item ID
> Integer itemId = new Integer(itemStr);
>
> try
> {
> item = (Item) sess.get(Item.class, itemId);
> }
> catch (HibernateException he)
> {
> printError("Failed to execute Query for item: " + he, sp);
> releaseSession(sess);
> return;
> }
> if (item == null)
> {
> printError("<h2>This item does not exist!</h2>", sp);
> releaseSession(sess);
> return;
> }
>
> try
> {
> Query q = sess.createFilter(item.getBids(), "select
> max(this.bid)");
> List lst = q.list();
> Iterator it = lst.iterator();
>
> // Get the current price (max bid)
> if (it.hasNext())
> maxBid = (Float) it.next();
> else
> maxBid = item.getInitialPrice();
> }
> catch (HibernateException he)
> {
> printError("Failed to executeQuery for max bid: " + he, sp);
> releaseSession(sess);
> return;
> }
>
> try
> {
> Query q = sess.createFilter(item.getBids(), "select count(*)");
> List lst = q.list();
> Iterator it = lst.iterator();
>
> if (it.hasNext())
> nbOfBids = (Integer) it.next();
> }
> catch (HibernateException he)
> {
> printError("Failed to executeQuery for number of bids: " + he,
> sp);
> releaseSession(sess);
> return;
> }
>
> sp.printItemDescription(item, maxBid, nbOfBids, user, sess);
>
> releaseSession(sess);
>
> sp.printHTMLfooter();
> }
> --------------------
> Thank you in advance for your help and attention
> Arash
> --
> View this message in context:
> http://www.nabble.com/NullPointerException-error-
> tp25631989p25631989.html
> Sent from the java.net - glassfish users mailing list archive at
> Nabble.com.
>
>
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