Custom tag in JSPTableContainerProvider/tabletopbottom.jsp

Tried creating a new tag based upon 'getHasFrame' tag in 'desktopTable.tld'. The jsp referenced above throws the following exception:
ERROR: JspRequestDispatcher:
javax.servlet.ServletException: Problem processing JSP: /../JSPTableContainerProvider/tabletopbottom.jsp
at com.sun.portal.providers.jsp.JspRequestDispatcher.getJspResource(JspRequestDispatcher.java:164)
at com.sun.portal.providers.jsp.JspRequestDispatcher.include(JspRequestDispatcher.java:97)
at org.apache.jasper.runtime.PageContextImpl.include(PageContextImpl.java:408)
at jsps.etc._opt._SUNWps._desktop._pinpoint_en_US._Home._html._table_jsp._jspService(_table_jsp.java:526)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.sun.portal.providers.jsp.JspServletWrapper.service(JspServletWrapper.java:182)
at com.sun.portal.providers.jsp.JSPProvider.processJspFile(JSPProvider.java:692)
at com.sun.portal.providers.jsp.JSPProvider.processJspFile(JSPProvider.java:672)
at com.sun.portal.providers.jsp.JSPProvider.getContent(JSPProvider.java:471)
at com.sun.portal.desktop.context.PSContainerProviderContext.getContent(PSContainerProviderContext.java:367)
at com.sun.portal.desktop.taglib.containerProviderContext.GetContentTag.doStartTag(GetContentTag.java:33)
at jsps.etc._opt._SUNWps._desktop._pinpoint_en_US._PinPointTabContainer._html._tab_jsp._jspService(_tab_jsp.java:596)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.sun.portal.providers.jsp.JspServletWrapper.service(JspServletWrapper.java:182)
at com.sun.portal.providers.jsp.JSPProvider.processJspFile(JSPProvider.java:692)
at com.sun.portal.providers.jsp.JSPProvider.processJspFile(JSPProvider.java:672)
at com.sun.portal.providers.jsp.JSPProvider.getContent(JSPProvider.java:471)
at com.sun.portal.providers.containers.jsp.tab.JSPTabContainerProvider.getContent(JSPTabContainerProvider.java:535)
at com.sun.portal.desktop.context.PSContainerProviderContext.getContent(PSContainerProviderContext.java:367)
at com.sun.portal.desktop.context.PSDesktopContext.getContent(PSDesktopContext.java:957)
at com.sun.portal.desktop.DesktopServlet.doGetPost(DesktopServlet.java:493)
at com.sun.portal.desktop.DesktopServlet.service(DesktopServlet.java:303)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at com.iplanet.server.http.servlet.NSServletRunner.invokeServletService(NSServletRunner.java:897)
at com.iplanet.server.http.servlet.WebApplication.service(WebApplication.java:1059)
at com.iplanet.server.http.servlet.NSServletRunner.ServiceWebApp(NSServletRunner.java:959)
The tagclass referenced by the tag was compiled on the server.
No logging associated with the doStartTag() method or the tag's constructor ever comes through.
Seems like it can't find the class at all ?
The jsp complains about this line:
<dttable:getHasHeader id="hasHeader" scope="request"/>
where --
<%@ taglib uri="/tld/desktopTable.tld" prefix="dttable" %>
and the tld file contains the following tag:
<tag>
<name>getHasHeader</name>
<tagclass>com.xyz.portal.desktop.tags.GetHasHeaderTag</tagclass>
<bodycontent>empty</bodycontent>
<attribute>
<name>id</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
</tag>
Any clues ?

Has anyone been able to get their own tags to work? Here's the very odd situation to clarify a little of what my colleague originally posted:
Custom tag class written based on the 'getHasFrame' tag
Added a declaration to the desktopTable.tld file for the tag
Put the classes in
....../desktop/classes
...../SUNWam/lib
as both jar files and plain-old class files
Made sure the jars and directories are in the classpath property in jvm12.conf and in the jspCompilerWARClassPath property of desktopconfig.properties (trying anything at this point)
Even if the tag is screwed up, here's the kicker....I just did a Class.forName() on the tag class and that throws a Throwable. eh? We've written a bunch of other custom classes that we just use in our JSPs with no problem. I don't get why this is such a special case.
Anybody got a clue for me?
In which directories did you place the tld and
*.class files for the taglib?
The class files should probably be in
/etc/opt/SUNWps/desktop/classes (or someplace else in
the web server's classpath)
The tld should probably be in
/etc/opt/SUNWps/desktop/default/tld (default may be
named differently if you changed the "desktop type"
in the admin console under the desktop definition).

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2003-04-15 09:28:46 jsp: init
2003-04-15 09:28:46 ApplicationModule release mode is: Stateful
Deploying on a standalone OC4J everything works.
Is there some configuration to add to the web.xml file or somewhere else? I tried also on Tomcat 4.0.3 with same results.
I added this lines in web.xml to avoid the problems descripted in thread BC4J entity objects vs EJB2.0 entity beans
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Thanks,
Marco.

Hi Steve,
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          J.
          James Strachan
          =============
          email: [email protected]
          web: http://www.metastuff.com
          "Sri" <[email protected]> wrote in message
          news:[email protected]...
          > This post had some interesting aspects about custom tags that contradict
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          > } finally
          >
          > if (_calico_thunder_presentation_tags_ForTag_0 != null)
          > calicothunder_presentation_tags_ForTag_0.release();
          > }
          >
          > Further down
          >
          > try {
          > calicothunder_presentation_tags_ForTag_1 = new
          > calico.thunder.presentation.tags.ForTag();
          > ...............
          >
          > } finally
          >
          > if (_calico_thunder_presentation_tags_ForTag_1 != null)
          > calicothunder_presentation_tags_ForTag_1.release();
          > }
          >
          > The code is creating two different objects for every request. It is not
          > reusing the same object.
          > The release is just cleaning up the current instance, which may be garbage
          > collected at some later stage.
          > So even if a page has 4 tags and 100 users, we have 400 objects just
          > because we use tags.
          >
          > Just trying to understand this better..
          > thanks - Sri
          >
          >
          >
          > "James Strachan" <[email protected]> wrote in message
          > news:[email protected]...
          > > Hi Jack
          > >
          > > I think you're right to be concerned and it is a valid concern.
          > >
          > > In the scheme of things in my experience the cost of using custom tags
          is
          > > quite minimal. Tag instances are reused on the same page so if I have
          > > several non-nested <foo:bar> tags on a page the single FooBarTag
          instance
          > > will be reused for each tag occurance.
          > >
          > > Consider other Java code, say, string concatenation. Consider the
          > following
          > > expression.
          > >
          > > String c = a + b;
          > >
          > > Fairly minimal code you might think. However this line actually involves
          > the
          > > creation of a StringBuffer instance, the call of 2 methods and the
          > creation
          > > of a second String object instance (never mind the internal char[]
          object
          > > instance that is created inside the new Strings constructor).
          > >
          > > A typical use of a custom tag involves one object construction, N
          > > setProperty() method calls (one for each attribute of the tag) and the
          > > startTag / endTag method calls.
          > >
          > > So on balance I'd say the custom tags mechanism is quite small and
          > > efficient.
          > >
          > > Though note that if you use large numbers (say hundreds) of different
          > kinds
          > > of tags then you'll have a much greater object allocation overhead.
          > >
          > > --
          > > J.
          > >
          > > James Strachan
          > > =============
          > > email: [email protected]
          > > web: http://www.metastuff.com
          > > "Jack Lin" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > I've been playing around a bit (alright, so maybe not all that much)
          > > > with custom tags, and it seems like the actual implementation of
          custom
          > > > tags (tag handler object(s) per tag) is much more resource-intensive
          > > > than would be justified. With Weblogic 5.1 SP6, has anyone had the
          > > > opportunity to compare performance of a typical JSP page w/ and w/out
          > > > custom tags?
          > > >
          > > > My first impression of custom tags was that you could define tags
          > > > and behaviors that the JSP compiler would then compile into your JSP
          > > > class; there would be no performance hit during page execution. The
          Java
          > > > code used to write these tags would either be included inline in the
          JSP
          > > > page code, or else act essentially as static (threadsafe) classes into
          > > > which threads executing JSP pages would call into. This approach means
          > > > less resources consumed and less setup/teardown time in exchange for
          > > > fatter JSPC'd code.
          > > > Instead (and correct me if I am wrong), it appears that each
          > > > distinct custom tag has a pool of instantiated handler objects lying
          > > > around in memory, and each time a custom tag is used, there is a
          > > > little performance hit in the setup & teardown of each handler
          object's
          > > > pageContext, etc...
          > > > Now admittedly, as another poster (I believe Mr. Purdy) pointed
          out,
          > > > a "little" ain't all that much... unless there are thousands of those
          > > > "little" hits.
          > > > Moreover, I don't see much benefit in having instantiated objects
          do
          > > > the heavy lifting. I'd rather have my auto-compiled JSP classes be a
          > > > little more bloated than suffer any performance hit. (I do, however,
          > > > like the fact that custom tags allows for cleaner JSP code, not to
          > > > mention makes for a cleaner break between the creative and coding
          work.)
          > > >
          > > > For those of you who've had more extensive experience with custom
          > > > tags, am I missing the target? Is the performance hit negligible for
          > > > heavily-used or complex pages? And/or is the performance hit
          outweighed
          > > > by code and development cleanliness?
          > > >
          > > > Thanks for any input.
          > > > Jack
          > > >
          > > >
          > >
          > >
          >
          >

Custom tag as performance hits.

          Hi All,
          I want to know if there is a correlation between the number of custom tags used in
          a JSP page and the page's performance.
          Is there a guideline/study which indicates (or otherwise) that increasing the number
          of custom tags decreases the loading (rendering) time of the JSP page. I understand
          that more tags mean more jsp-compilation time but I am interested in runtime performance.
          Thanks,
          Anu


I want to know if there is a correlation between the number of custom tags          used in
          > a JSP page and the page's performance.
          >
          > Is there a guideline/study which indicates (or otherwise) that increasing
          the number
          > of custom tags decreases the loading (rendering) time of the JSP page. I
          understand
          > that more tags mean more jsp-compilation time but I am interested in
          runtime performance.
          Each additional tag adds some runtime overhead. The overhead is primarily
          determined by the quality of the tag implementation. I'd rather have 1000
          well written tags than 1 poorly written one ;-) ... e.g. if you are doing
          JDBC calls from a tag, then you will probably get into trouble in a hurry.
          Peace,
          Cameron Purdy
          Tangosol, Inc.
          Clustering Weblogic? You're either using Coherence, or you should be!
          Download a Tangosol Coherence eval today at http://www.tangosol.com/
          "Anu Agrawal" <[email protected]> wrote in message
          news:3cd821c0$[email protected]..
          >

Further custom tag travails...

All,
          I have posted previously that custom tags can not handle JSP in their
          attributes. This turns out to be incorrect. In fact, they can, but
          there are some serious bugs when using it which made it seem like they
          couldn't.
          The following jsp works perfectly fine:
          <% String myAttribute="Thusly my attribute is" %>
          <mytaglib:mytag myattribute="<%=myAttribute%>" />
          However, the following jsp will break:
          <mytaglib:mytag myattribute="<%="Thusly my attribute is"%>" />
          because the jsp parser thinks that the second quote is ending the
          attribute instead of starting a string. Hence, the jsp compiler sees:
          <mytaglib:mytag myattribute="<%="
          and then some garbage including a > which it assumes means that mytag is
          closing. This really, really screws things up...
          The exact error I get is:
          /tagtester.jsp(38): no corresponding open tag for tag extension close:
          Now, I also get an error if I do something like this:
          <% String myAttribute="Thusly my attribute is" %>
          <mytaglib:mytag myattribute=" <%=myAttribute%>" />
          Where I have put some one space before the jsp. The error message is
          different:
          /_tagtester.java:84: String not terminated at end of line.
          Looking at the jsp .java file indicates that this also is a parsing
          problem...
          Is weblogic aware of these issues? Will they be fixed in sp6?
          Thanks,
          Carson


This is a consequence of the JSP spec and how it parses attribute values.
          Similar issues occur using standard boilerplate XML.
          The easy way around these problems is to use the fact that both single and
          double quotes are allowable in XML attribute values so try using code like
          this instead:-
          <mytaglib:mytag myattribute='<%="Thusly my attribute is"%>' />
          Then you will not get any JSP compilation errors.
          Regards
          James
          James Strachan
          =============
          email: [email protected]
          web: http://www.metastuff.com
          "Cameron Purdy" <[email protected]> wrote in message
          news:[email protected]...
          > I saw this refererred to (in a different context altogether) in some W3
          > documents referring to issues with input type attributes and xml ... I
          think
          > in the context of XSL. In other words, I am not sure if it is a WL bug or
          > just something that you can not do. I know that isn't the answer that you
          > are looking for ;-( ... perhaps you can escape some of those quotes.
          >
          > --
          >
          > Cameron Purdy
          > [email protected]
          > http://www.tangosol.com
          > WebLogic Consulting Available
          >
          >
          > "Carson Gross" <[email protected]> wrote in message
          > news:[email protected]...
          > > All,
          > >
          > > I have posted previously that custom tags can not handle JSP in their
          > > attributes. This turns out to be incorrect. In fact, they can, but
          > > there are some serious bugs when using it which made it seem like they
          > > couldn't.
          > >
          > > The following jsp works perfectly fine:
          > >
          > > <% String myAttribute="Thusly my attribute is" %>
          > > <mytaglib:mytag myattribute="<%=myAttribute%>" />
          > >
          > > However, the following jsp will break:
          > >
          > > <mytaglib:mytag myattribute="<%="Thusly my attribute is"%>" />
          > >
          > > because the jsp parser thinks that the second quote is ending the
          > > attribute instead of starting a string. Hence, the jsp compiler sees:
          > >
          > > <mytaglib:mytag myattribute="<%="
          > >
          > > and then some garbage including a > which it assumes means that mytag is
          > > closing. This really, really screws things up...
          > >
          > > The exact error I get is:
          > >
          > > /tagtester.jsp(38): no corresponding open tag for tag extension close:
          > >
          > > Now, I also get an error if I do something like this:
          > >
          > > <% String myAttribute="Thusly my attribute is" %>
          > > <mytaglib:mytag myattribute=" <%=myAttribute%>" />
          > >
          > > Where I have put some one space before the jsp. The error message is
          > > different:
          > > /_tagtester.java:84: String not terminated at end of line.
          > >
          > > Looking at the jsp .java file indicates that this also is a parsing
          > > problem...
          > >
          > > Is weblogic aware of these issues? Will they be fixed in sp6?
          > >
          > > Thanks,
          > > Carson
          > >
          >
          >

"Newbie Unable to load class for custom tag"

I have recently written a custom tag but I have been unable to implement it in a JSP because the server is unable to load the .class file. Below I have supplied the files that contribute to make up the custom tag, aswell as the JSP file used to implement it.
genericDBConnect.java
stored in C:\jakarta-tomcat-3.2.3\webapps\exper\WEB-INF\classes\jsp\tags\dbase
package jsp.tags.dbase;
import java.io.*;
import java.sql.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
public class genericDBConnect extends BodyTagSupport
private String odbcDriver;
private String dataSource;
public void setOdbcDriver(String driver)
odbcDriver = driver;
public void setDataSource(String source)
dataSource = source;
public int doStartTag() throws JspException
return EVAL_BODY_INCLUDE;
public int doEndTag() throws JspException
try{
pageContext.getOut().print("This is the value of odbcDriver = " + odbcDriver + "and dataSource = " + dataSource);
     catch(Exception ioException)
     System.err.println("Exception thrown in genericDBConnect.doEndTag():");
     System.err.println(ioException);
     throw new JspException(ioException);
return EVAL_PAGE;
WEB.XML
Stored in: C:\jakarta-tomcat-3.2.3\webapps\exper\WEB-INF
<!DOCTYPE web-app PUBLIC
     "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
     "http://java.sun.com/dtd/web-app_2_2.dtd">
<web-app>
     <display-name>Generic database Connector</display-name>
     <description>
     Connecting to a database using dataSource and OdbcDriver
          Attributes as well as sending a query to the database;
     </description>
     <taglib>
          <taglib-uri>/genericdbconnecttags.tld</taglib-uri>
          <taglib-location>/WEB-INF/genericdbconnecttags.tld</taglib-location>
     </taglib>
</web-app>
genericdbconnecttags.tld
C:\jakarta-tomcat-3.2.3\webapps\exper\WEB-INF
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE taglib
PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
     "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
     <tlib-version>1.0</tlib-version>
     <jsp-version>1.2</jsp-version>
     <short-name>genericDBConnect</short-name>
     <tag>
          <name>dbconnect</name>
          <tag-class>jsp.tags.dbase.genericDBConnect</tag-class>
          <attribute>
               <name>dataSource</name>
               <required>true</required>
               <rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
               <name>odbcDriver</name>
               <required>true</required>
               <rtexprvalue>true</rtexprvalue>
     </attribute>
     </tag>
</taglib>
DBTester.jsp
Stored in:C:\jakarta-tomcat-3.2.3\webapps\exper
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
     <title>Generic dataBase Connection</title>
</head>
<body>
<%@ taglib uri="/genericdbconnecttags.tld" prefix="database" %>
<database:dbconnect odbcDriver="sun.my.tag.lib" dataSource="hello">
this is the the begining of the end of life as we know it
</database:dbconnect>
</body>
</html>
And this is the error I get:
Error: 500
Location: /exper/DBtester.jsp
Internal Servlet Error:
org.apache.jasper.compiler.CompileException: C:\jakarta-tomcat-3.2.3\webapps\exper\DBtester.jsp(8,0) Unable to load class null
     at org.apache.jasper.compiler.TagBeginGenerator.init(TagBeginGenerator.java:129)
     at org.apache.jasper.compiler.JspParseEventListener$GeneratorWrapper.init(JspParseEventListener.java:759)
     at org.apache.jasper.compiler.JspParseEventListener.addGenerator(JspParseEventListener.java:138)
     at org.apache.jasper.compiler.JspParseEventListener.handleTagBegin(JspParseEventListener.java:909)
     at org.apache.jasper.compiler.DelegatingListener.handleTagBegin(DelegatingListener.java:194)
     at org.apache.jasper.compiler.Parser$Tag.accept(Parser.java:825)
     at org.apache.jasper.compiler.Parser.parse(Parser.java:1077)
     at org.apache.jasper.compiler.Parser.parse(Parser.java:1042)
     at org.apache.jasper.compiler.Parser.parse(Parser.java:1038)
     at org.apache.jasper.compiler.Compiler.compile(Compiler.java:209)
     at org.apache.jasper.servlet.JspServlet.doLoadJSP(JspServlet.java:612)
     at org.apache.jasper.servlet.JasperLoader12.loadJSP(JasperLoader12.java:146)
     at org.apache.jasper.servlet.JspServlet.loadJSP(JspServlet.java:542)
     at org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(JspServlet.java:258)
     at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:268)
     at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429)
     at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
     at org.apache.tomcat.core.Handler.service(Handler.java:287)
     at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
     at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
     at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
     at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
     at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
     at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
     at java.lang.Thread.run(Thread.java:484)
Please if you can help I will be very grateful

I was searching about this problem and I found here.
I'm using WSAD 4.0.3 and I'm making my first custom tag.
Here is my files:
======================= CLASS ======================
package sas.ric.tags.teste;
import javax.servlet.jsp.tagext.TagSupport;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import java.io.IOException;
public class ClTagHello extends TagSupport {
public int doStartTag() {
     try {
          JspWriter out = pageContext.getOut();
          out.println("HELLO!");
     } catch (IOException ioe) {
          System.out.println("Erro in ClTagHello: " + ioe);
return (SKIP_BODY);
================= TLD ==========================
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
     <tlib-version>1.0</tlib-version>
     <jsp-version>1.2</jsp-version>
     <short-name>ric</short-name>
     <uri></uri>
     <info>Exemple</info>
     <tag>
          <name>hello</name>
          <tag-class>sas.ric.tags.teste.ClTagHello</tag-class>
          <body-content>empty</body-content>
     </tag>
</taglib>
======================== JSP =====================
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>
<HEAD>
<META name="GENERATOR" content="IBM WebSphere Studio">
<META http-equiv="Content-Style-Type" content="text/css">
</HEAD>
<%@ taglib uri="WEB-INF/app-tlds/tag-hello.tld" prefix="ric" %>
<BODY>
<ric:hello />
</BODY>
</HTML>
==========================================================
Please, help me.
Occur this error "JSPG0058E: Unable to load class null"
Thank's

Custom tag in JSPTableContainerProvider/tabletopbottom.jsp

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