how to generate .hbm.xml files and .java files using build.xml

it gives me error like
build failed

build.xml:30: java.lang.NoClassDefFoundError: org/hibernate/engine/Mapping

my build.xml file is
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<?xml version="1.0"?>

<project name="lms" default="" basedir=".">

<property name="resources.dir" value="${basedir}/src/main/resources" />
<property name="java.dir" value="${basedir}/src/main/java" />
<property name="java.domain.core.dir" value="${java.dir}/com/abm/lms/domain/core/demo" />
<property name="java.generator.dir" value="${java.dir}/com/ao2/smart/generator" />
<property name="classes.dir" value="${basedir}/WebContent/WEB-INF/classes" />
<property name="lib.dir" value="${basedir}/WebContent/WEB-INF/lib" />
<property name="tab" value="&#x0009;" />
<property name="http.proxyHost" value="proxy.RAVI-LENOVO"/>
<property name="http.proxyPort" value="8443"/>

<path id="toolslib">
<path location="${lib.dir}/hibernate-core-4.1.0.Final.jar" />

<fileset dir="${lib.dir}">
<include name="*.jar"/>
</fileset>
</path>

<taskdef name="hibernatetool" classname="org.hibernate.tool.ant.HibernateToolTask" classpathref="toolslib" />

<target name="CodeGen.GenerateDomainObjects" depends="CodeGen.AdjustCollections,CodeGen.AddOrphanRemoval,CodeGen.AddSerialVersion, CodeGen.ChildAddMethodInjector">
</target>

<!-- Generate hbm.xml and java files -->
<target name="CodeGen.RunHibernateTool" description="generate hibernate classes n java classes">
<hibernatetool destdir="${java.dir}">

<jdbcconfiguration configurationfile="${resources.dir}/hibernate.cfg.xml" packagename="com.abm.lms.domain.core.demo" revengfile="${basedir}\hibernate.reveng.xml" detectmanytomany="true" />
<hbm2hbmxml />
<hbm2java jdk5="true" ejb3="true" />

</hibernatetool>

</target>


<!-- Searches and replaces the two regular expressions -->
<target name="CodeGen.AdjustCollections">

<replaceregexp byline="true">
<regexp pattern="import java.util.HashSet;" />
<substitution expression="import java.util.ArrayList;" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>

<replaceregexp byline="true">
<regexp pattern="import java.util.Set;" />
<substitution expression="import java.util.List;" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>

<replaceregexp byline="true">
<regexp pattern="new HashSet" />
<substitution expression="new ArrayList" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>

<replaceregexp flags="g">
<regexp pattern="Set&lt;(\w*)&gt;" />
<substitution expression="List&lt;\1&gt;" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>

</target>

<target name="CodeGen.AddOrphanRemoval">
<replaceregexp byline="true">
<regexp pattern="@OneTo(.*)\)" />
<substitution expression="${tab}@OneTo\1, cascade = javax.persistence.CascadeType.ALL, orphanRemoval = true)" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>
</target>

<target name="CodeGen.AddSerialVersion">
<replaceregexp>
<regexp pattern="implements java\.io\.Serializable\s*\{" />
<substitution expression="implements java\.io\.Serializable${line.separator}{${line.separator}${tab}private static final long serialVersionUID = 1L;" />
<fileset dir="${java.domain.core.dir}" includes="*.java" />
</replaceregexp>
</target>

<target name="CodeGen.ChildAddMethodInjector">

<java classname="com.ao2.smart.generator.ChildAddMethodInjector" fork="yes">
<sysproperty key="http.proxyHost" value="${http.proxyHost}" />
<sysproperty key="http.proxyPort" value="${http.proxyPort}" />
<sysproperty key="xslt.file" value="${java.generator.dir}/ChildAddMethodInjector.xsl" />
<sysproperty key="xml.files.dir" value="${java.domain.core.dir}" />
<classpath>
<path location="${classes.dir}"/>
<path refid="toolslib"/>
</classpath>
</java>

</target>

<target name="CodeGen.FieldLabelsProperties">

<java classname="com.ao2.smart.generator.FieldLabelsGenerator" fork="yes">
<sysproperty key="http.proxyHost" value="${http.proxyHost}" />
<sysproperty key="http.proxyPort" value="${http.proxyPort}" />
<sysproperty key="xslt.file" value="${java.generator.dir}/FieldLabelsGenerator.xsl" />
<sysproperty key="xml.files.dir" value="${java.domain.core.dir}" />
<sysproperty key="output.file" value="${resources.dir}/field-labels.properties" />
<classpath>
<path location="${classes.dir}"/>
<path refid="toolslib"/>
</classpath>
</java>

</target>

</project>
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reply soon
thanks