如何在Servlet上从bytearray返回zip

Question

再次使用Java EE。

在示例

1. 在servlet上我有byte[] fileContent ---->(file.txt)
2. 我试着添加到zip文件

3. 设置servlet为

   response.setContentType("Content-type: text/zip");
   response.setHeader("Content-Disposition",
           "attachment; filename=mytest.zip");
   // List of files to be downloaded
   List files = new ArrayList();
   files.add(new File("C:/first.txt"));
   ServletOutputStream out = response.getOutputStream();
   ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(out));
   for (File file : files) {
       System.out.println("Adding " + file.getName());
       zos.putNextEntry(new ZipEntry(file.getName()));
       // Get the file
       FileInputStream fis = null;
       try {
           fis = new FileInputStream(file);
       } catch (FileNotFoundException fnfe) {
           // If the file does not exists, write an error entry instead of
           // file
           // contents
           zos.write(("ERRORld not find file " + file.getName())
                   .getBytes());
           zos.closeEntry();
           System.out.println("Couldfind file "
                   + file.getAbsolutePath());
           continue;
       }
       BufferedInputStream fif = new BufferedInputStream(fis);
       // Write the contents of the file
       int data = 0;
       while ((data = fif.read()) != -1) {
           zos.write(data);
       }
       fif.close();
       zos.closeEntry();
       System.out.println("Finishedng file " + file.getName());
   }
   zos.close();
   

   }}

我对第二点有问题。我尝试了几种解决方案，但它们都很难与我的servlet一起工作或不起作用。

有人能告诉我一个例子如何添加文件作为字节数组压缩和返回servlet作为附件?谢谢你的建议和建议

,文章编辑

我尝试了类似的东西，但是我如何添加byte[]而不是file

Answer 1

解决方案示例:

public class ZipFileServlet extends HttpServlet {
private static final int DEFAULT_BUFFER_SIZE = 10240; // 10KB.
private YourFileDAO yourFileDAO = YourDAOFactory.getYourFileDAO();
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException
{
    String[] fileIds = request.getParameterValues("fileId");
    response.setContentType("application/zip");
    response.setHeader("Content-Disposition", "attachment; filename="allfiles.zip"");
    ZipOutputStream output = null;
    byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
    try {
        output = new ZipOutputStream(new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE));
        for (String fileId : fileIds) {
            YourFileItem item = yourFileDAO.find(fileId);
            if (item == null) continue; // Handle yourself. The fileId may be wrong/spoofed.
            InputStream input = null;
            try {
                input = new BufferedInputStream(item.getInputStream(), DEFAULT_BUFFER_SIZE);
                output.putNextEntry(new ZipEntry(item.getName()));
                for (int length = 0; (length = input.read(buffer)) > 0;) {
                    output.write(buffer, 0, length);
                }
                output.closeEntry();
            } finally {
                if (input != null) try { input.close(); } catch (IOException logOrIgnore) { /**/ }
            }
        }
    } finally {
        if (output != null) try { output.close(); } catch (IOException logOrIgnore) { /**/ }
    }
}
 }