Webapp Precompilation using Ant and Jasper howto

[Johannes Fiala]

Hi there,

I read the Jasper howto 
(http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jasper-howto.html), but I 
didn't get the build.xml file to work.

here's the commandline I typed in:
F:\src>ant -Dtomcat.home=f:/tomcat-4.1.18 
-Dwebapp.path=f:/tomcat-4.1.18/webapps/myapp

I get the following error:
====================================
Buildfile: build.xml

jspc:
2003-03-23 03:26:39 - ERROR-the file '\views\liste.jsp' gene
rated the following general exception: java.lang.NullPointerException
  [jasper2] Error in class org.apache.jasper.JspC

BUILD FAILED
file:F:/soap/esv/src/build.xml:21: org.apache.jasper.JasperException

Total time: 2 seconds
====================================

liste.jsp itself is simply empty, so it seems that Jasper didn't produce 
any output! I tried it both with tomcat running and tomcat stopped.

here's the build.xml file in F:\src\build.xml:
<project name="Webapp Precompilation" default="all" basedir=".">

  <target name="jspc">

    <taskdef classname="org.apache.jasper.JspC" name="jasper2" >
      <classpath id="jspc.classpath">
        <pathelement location="${java.home}/../lib/tools.jar"/>
        <fileset dir="${tomcat.home}/server/lib">
          <include name="*.jar"/>
        </fileset>
        <fileset dir="${tomcat.home}/common/lib">
          <include name="*.jar"/>
        </fileset>
      </classpath>
    </taskdef>

    <jasper2
             validateXml="false"
             uriroot="${webapp.path}"
             webXmlFragment="${webapp.path}/WEB-INF/generated_web.xml"
             outputDir="${webapp.path}/WEB-INF/src" />

  </target>

  <target name="compile">

    <mkdir dir="${webapp.path}/WEB-INF/classes"/>
    <mkdir dir="${webapp.path}/WEB-INF/lib"/>

    <javac destdir="${webapp.path}/WEB-INF/classes"
           optimize="off"
           debug="on" failonerror="false"
           srcdir="${webapp.path}/WEB-INF/src"
           excludes="**/*.smap">
      <classpath>
        <pathelement location="${webapp.path}/WEB-INF/classes"/>
        <fileset dir="${webapp.path}/WEB-INF/lib">
          <include name="*.jar"/>
        </fileset>
        <pathelement location="${tomcat.home}/common/classes"/>
        <fileset dir="${tomcat.home}/common/lib">
          <include name="*.jar"/>
        </fileset>
        <pathelement location="${tomcat.home}/shared/classes"/>
        <fileset dir="${tomcat.home}/shared/lib">
          <include name="*.jar"/>
        </fileset>
      </classpath>
      <include name="**" />
      <exclude name="tags/**" />
    </javac>

  </target>

  <target name="all" depends="jspc,compile">
  </target>

</project>

Can anybody shed any light onto this issue?

thx alot
Johannes