PMD ANT script gives taskdef class net.sourceforge.pmd.ant.PMDTask cannot be found using the classloader AntClassLoader[] - ant

Question

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project basedir="." default="info" name="MyProject">
<property name="src.dir" value="src"/>
<property name="build.dir" value="build"/>
<property name="classes.dir" value="${build.dir}/classes"/>
<property name="jar.dir" value="${build.dir}/jar"/>
<property name="lib.dir" value="lib"/>
<property name="jar.name" value="${ant.project.name}"/>
<path id="classpath">
<fileset dir="${lib.dir}" includes="**/*.jar"/>
</path>
<target name="clean">
<delete dir="${build.dir}"/>
</target>
<target name="compile" depends="clean">
<mkdir dir="${classes.dir}"/>
<javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath" debug="true" nowarn="true" debuglevel="lines,vars,source"/>
</target>
<target name="jar" depends="compile">
<mkdir dir="${jar.dir}"/>
<jar destfile="${jar.dir}/${jar.name}.jar" basedir="${classes.dir}">
<exclude name="**/Main.class" />
<fileset dir="${src.dir}" includes="**/*.java">
<exclude name="**/Main.java" />
</fileset>
<zipgroupfileset dir="${lib.dir}" includes="*.jar">
<exclude name="**/Utils.jar" />
</zipgroupfileset>
</jar>
</target>
<target name="build" depends="jar"/>
<taskdef name="pmd" classname="net.sourceforge.pmd.ant.PMDTask" />
<target name="pmd">
<pmd shortFilenames="true" failuresPropertyName="failures.count" rulesetfiles="\path\pmd\ruleSet.xml">
<formatter type="html" toFile="pmd_report.html" toConsole="true"/>
<fileset dir="src">
<include name="**/*.java"/>
</fileset>
</pmd>
</target>
<target name="info">
<echo message="Available Targets:"/>
<echo message=" clean"/>
<echo message=" compile"/>
<echo message=" jar"/>
<echo message=" build"/>
<echo message=" pmd"/>
</target>
</project>
This script gives me this " taskdef class net.sourceforge.pmd.ant.PMDTask cannot be found using the classloader AntClassLoader[]"
I have added PMD library jar file in lib folder of the project,where other libraries are present as jar files.
But if i change add path ref to the library not as a jarfile , it works well.
<path id="pmd.classpath">
<fileset dir="C:\Users\PMD\pmd-bin-5.5.2">
<include name="**/*.jar"/>
</fileset>
</path>
May I know what is the problem? I am pretty new to ANT and PMD , any help will be appreciated.
Thanks

Answer 1

First thing to check is the file pmd-core-*.jar in your lib directory?
Secondly add a reference to the path in the taskdef task:
<taskdef name="pmd" classname="net.sourceforge.pmd.ant.PMDTask" classpathref="classpath"/>