ant 的native2ascii unicode转换不正确问题

用ant的native2ascii将含中文的js文件转为ascii，再转为utf8和unicode：
GBK－>ascii->UTF8
ascii->Unicode
UTF8转换正确，但是转为Unicode时，第一个汉字的escaped unicode编码总是不能转为unicode编码。


<project name="encodetrans" default="main" basedir=".">
    <target name="gbk2ascii" >
      <native2ascii src="d:/test/" encoding="GBK" includes="*1.js" dest="d:/test/test1" />
   </target>
   <target name="ascii2utf8" depends="gbk2ascii">
      <native2ascii src="d:/test/test1" encoding="UTF-8" reverse="true" includes="*1.js" ext=".utf" dest="d:/test/test1" />
   </target>
   <target name="ascii2unicode" depends="gbk2ascii">
      <native2ascii src="d:/test/test1" encoding="Unicode" reverse="true" includes="*.js" ext=".uni" dest="d:/test/test1" />
   </target>
   
   <target name="main" depends="ascii2utf8,ascii2unicode">
   </target>
</project>

用Jdk的native2ascii.exe，也存在同样的问题
native2ascii -encoding Unicode -reverse a1.js a1.uni1

请问哪位仁兄知道如何解决
我用的是win2000 server,jdk1.4.1,ant版本换了三个都一样（1.4、1.5.1、1.5.2）

看看这个，希望对你有帮助!
private void convertToUnicode(File src, File dest) {
try {
BufferedReader br = new BufferedReader(new FileReader(src));
BufferedWriter bw = new BufferedWriter(new FileWriter(dest));

String str, tmp;
char c;
int i, j, k;
StringBuffer sb = new StringBuffer(1000);

while ((str = br.readLine()) != null) {
sb.setLength(0);
for (i = 0; i < str.length(); i++) {
c = str.charAt(i);
if (c > 255) {
sb.append("\\u");
j = (c >>> 8);
tmp = Integer.toHexString(j);
if (tmp.length() == 1) sb.append("0");
sb.append(tmp);
j = (c & 0xFF);
tmp = Integer.toHexString(j);
if (tmp.length() == 1) sb.append("0");
sb.append(tmp);

}
else {
sb.append(c);
}
}
bw.write(sb.toString(), 0, sb.length());
bw.newLine();
}
br.close();
bw.close();

} catch(IOException err) {
err("Error processing file " + src + ", reason: " + err.getMessage());
}
}