code: private static void copy(ZipFile zipFile, ZipEntry zipEntry, File outItemFile) throws IOException {
  		InputStream in = null;
  		OutputStream out = null;
  		try {
  			in = zipFile.getInputStream(zipEntry);
  			out = FileUtil.getOutputStream(outItemFile);
  			IoUtil.copy(in, out);
  		} finally {
  			IoUtil.close(out);
  			IoUtil.close(in);
  		}
  	}
docs: 从Zip文件流中拷贝文件出来
  
  @param zipFile Zip文件
  @param zipEntry zip文件中的子文件
  @param outItemFile 输出到的文件
  @throws IOException IO异常