androir打包工具----java压缩成apk问题

打包工具流程：
  1.在eclipse中到处未签名的apk
  2.用java将其解压
  3.修改一些文件，
  4.用java压缩成apk
  5.对apk签名
  整个流程在压缩这一环出现了问题，java将文件压缩成apk时在每个文件下多了一个无名且文件大小为0的文件，签名安装后，打开程序报xml文件找不到。
  试过手动删除无效文件再签名，一切OK
  压缩方法如下：
  //对文件进行压缩
public static void zip(String sourceDir, String zipFile) {
OutputStream os;
try {
os = new FileOutputStream(zipFile);
BufferedOutputStream bos = new BufferedOutputStream(os);
ZipOutputStream zos = new ZipOutputStream(bos);

File file = new File(sourceDir);

String basePath = null;
if (file.isDirectory()) {
basePath = file.getPath();
} else {
basePath = file.getParent();
}

zipFile(file, basePath, zos);

zos.closeEntry();
zos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(".......文件压缩成功");
FileUtil.deleteDirectory(sourceDir);
}


private static void zipFile(File source, String basePath,
ZipOutputStream zos) {
File[] files = new File[0];

if (source.isDirectory()) {
files = source.listFiles();
} else {
files = new File[1];
files[0] = source;
}

String pathName;
byte[] buf = new byte[BUFFER];
int length = 0;
try {
for (File file : files) {
if (file.isDirectory()) {
pathName = file.getPath().substring(basePath.length() + 1)+ "\\";
zos.putNextEntry(new ZipEntry(pathName));
zipFile(file, basePath, zos);
} else {
pathName = file.getPath().substring(basePath.length() + 1);
InputStream is = new [/size] FileInputStream(file);
BufferedInputStream bis = new BufferedInputStream(is);
zos.putNextEntry(new ZipEntry(pathName));
while ((length = bis.read(buf)) > 0) {
zos.write(buf, 0, length);
}
is.close();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
希望大神们看下什么问题导致的[/size]