使用Java和Google App Engine在sp上载的zip文件中解压缩特定文件

Question

我试图找出使用Java和Google App Engine解压缩特定文件的解决方案。 我尝试使用ZipInputStream，但无法访问在jsp中上载的zip文件。 有人可以帮助我摆脱困境吗？

ServletFileUpload upload = new ServletFileUpload();
             resp.setContentType("text/plain");
             FileItemIterator iterator = upload.getItemIterator(req);
              while (iterator.hasNext()) {
                  FileItemStream fileItemStream = iterator.next();
                  InputStream InputStream = fileItemStream.openStream();
                  if (!fileItemStream.isFormField()) {
                      ZipInputStream zis = new ZipInputStream(new BufferedInputStream(InputStream));
                      ZipEntry entry;
                      while ((entry = zis.getNextEntry()) != null) {

                          //code to access required file in the zip file
                      }

                  } 
              }

Answer 1

我的猜测是ZipInputStream需要可搜索的流。 servlet（通常是网络）返回的流是不可搜索的。

尝试读取整个流，然后将其包装在ByteArrayInputStream ：

byte[] bytes = readBytes(fileItemStream.openStream());
InputStream bufferedStream = new ByteArrayInputStream(bytes);

public static byte[] readBytes(InputStream is) throws IOException {
  ByteArrayOutputStream buffer = new ByteArrayOutputStream();

  int len;
  byte[] data = new byte[100000];
  while ((len = is.read(data, 0, data.length)) != -1) {
    buffer.write(data, 0, len);
  }

  buffer.flush();
  return buffer.toByteArray();
}