<project name="sgfhibernate" basedir="C:\\Test\\Hibernate" default="gen_hibernate">

   <taskdef name="hibernatetool"
         classname="org.hibernate.tool.ant.HibernateToolTask">
         <classpath>
            <fileset dir="lib">
               <include name="**/*.jar"/>
            </fileset>
         </classpath>
   </taskdef>

   <target name="gen_hibernate"
         description="generate hibernate classes">
         <echo message="Base Dir : {basedir}"/>
         <echo message="The Project name is: ${ant.project.name}"/>

      <hibernatetool>
         <jdbcconfiguration
            configurationfile="hibernate.cfg.xml"
            packagename="com.hp.hibernate"
            revengfile="tables.reveng.xml"   
            detectmanytomany="true"
         />
         <hbm2java  destdir="src" />
         <hbm2hbmxml destdir="src" /> 
      </hibernatetool>
      
      

   </target>

</project>

import java.io.File;

import org.apache.tools.ant.DefaultLogger;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectHelper;


public class InvokeAntScript {

   /**
    * @param args
    */
   public static void main(String[] args) {
      File buildFile = new File("C:\\Test\\Hibernate\\build.xml");
      Project p = new Project();
      p.setUserProperty("ant.file", buildFile.getAbsolutePath());
      
      p.init();
      ProjectHelper helper = ProjectHelper.getProjectHelper();
      p.addReference("ant.projectHelper", helper);
      
      helper.parse(p, buildFile);
      DefaultLogger consoleLogger = new DefaultLogger();
      consoleLogger.setErrorPrintStream(System.err);
      consoleLogger.setOutputPrintStream(System.out);
      consoleLogger.setMessageOutputLevel(Project.MSG_INFO);
      p.addBuildListener(consoleLogger);
      p.executeTarget(p.getDefaultTarget());

   }

}

[hibernatetool] Executing Hibernate Tool with a JDBC Configuration (for reverse engineering)
[hibernatetool] 1. task: hbm2java (Generates a set of .java files)
Exception in thread "main" C:\Test\Hibernate\build.xml:24: java.lang.ExceptionInInitializerError
   at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:116)
   at org.apache.tools.ant.Task.perform(Task.java:348)
   at org.apache.tools.ant.Target.execute(Target.java:390)
   at org.apache.tools.ant.Target.performTasks(Target.java:411)
   at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
   at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
   at InvokeAntScript.main(InvokeAntScript.java:28)
Caused by: java.lang.ExceptionInInitializerError
   at org.hibernate.tool.ant.JDBCConfigurationTask.doConfiguration(JDBCConfigurationTask.java:59)
   at org.hibernate.tool.ant.ConfigurationTask.getConfiguration(ConfigurationTask.java:55)
   at org.hibernate.tool.ant.HibernateToolTask.getConfiguration(HibernateToolTask.java:302)
   at org.hibernate.tool.ant.HibernateToolTask.getProperties(HibernateToolTask.java:318)
   at org.hibernate.tool.ant.ExporterTask.configureExporter(ExporterTask.java:94)
   at org.hibernate.tool.ant.Hbm2JavaExporterTask.configureExporter(Hbm2JavaExporterTask.java:34)
   at org.hibernate.tool.ant.ExporterTask.execute(ExporterTask.java:39)
   at org.hibernate.tool.ant.HibernateToolTask.execute(HibernateToolTask.java:186)
   at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
   ... 6 more
Caused by: net.sf.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
   at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:237)
   at net.sf.cglib.core.KeyFactory$Generator.create(KeyFactory.java:144)
   at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:116)
   at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:108)
   at net.sf.cglib.core.KeyFactory.create(KeyFactory.java:104)
   at org.hibernate.cfg.reveng.OverrideRepository.<clinit>(OverrideRepository.java:589)
   ... 20 more
Caused by: java.lang.reflect.InvocationTargetException
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at net.sf.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:384)
   at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:219)
   ... 25 more
Caused by: java.lang.SecurityException: class "org.hibernate.cfg.reveng.OverrideRepository$TableColumnKeyFactory$$KeyFactoryByCGLIB$$12c34424"'s signer information does not match signer information of other classes in the same package
   at java.lang.ClassLoader.checkCerts(ClassLoader.java:806)
   at java.lang.ClassLoader.preDefineClass(ClassLoader.java:487)
   at java.lang.ClassLoader.defineClassCond(ClassLoader.java:625)
   at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
   ... 31 more