ant 遇到 javadoc失败

最近在学习ant的知识，生成java doc时遇到一个问题
<javadoc destdir="${doc.dir}" author="true" 
version="true" use="true" windowtitle="STRUTS1.2 API" 
useexternalfile="yes">            <packageset dir="${src.dir}" defaultexcludes="yes" />            <doctitle><![CDATA[<h1>STRUTS1.2 Project</h1>]]></doctitle>            <bottom><![CDATA[<i>Document by Anhuixiao 2010.</i>]]></bottom>        </javadoc>用上面的编写方法，老提示
E:\eclipse\workspace\struts1.2\build.xml:128: Javadoc failed: java.io.IOException: CreateProcess: javadoc.exe -d D:\dist\api -use -windowtitle "STRUTS1.2 API" -doctitle "<h1>STRUTS1.2 Project</h1>" -bottom "<i>Document by Anhuixiao 2010.</i>" -classpath E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-antlr.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-bcel.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-bsf.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-log4j.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-oro.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-regexp.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-apache-resolver.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-commons-logging.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-commons-net.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-icontract.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-jai.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib\ant-javamail.jar;E:\eclipse\plugins\org.apache.ant_1.6.5\lib?Total time: 6 seconds看了一些资料说添加下面加粗部分可以解决，但在我机子上还是出错，我想是不是ant_1.6.5不支持这个，还是有其他的解决方案，谢谢给点意见
<javadoc destdir="${doc.dir}" author="true" 
version="true" use="true" windowtitle="STRUTS1.2 API" 
useexternalfile="yes">