在服务器上创建Zip文件，并使用java下载该Zip

Question

我有下面的代码从mkyong得到，到本地的zip文件。但，我的要求是在服务器上压缩文件，并需要下载。谁能帮忙吗。

写入zipFiles的代码：

public void zipFiles(File contentFile, File navFile)
{
    byte[] buffer = new byte[1024];

    try{
        // i dont have idea on what to give here in fileoutputstream
        FileOutputStream fos = new FileOutputStream("C:\\MyFile.zip");
        ZipOutputStream zos = new ZipOutputStream(fos);
        ZipEntry ze= new ZipEntry(contentFile.toString());
        zos.putNextEntry(ze);
        FileInputStream in = new FileInputStream(contentFile.toString());

        int len;
        while ((len = in.read(buffer)) > 0) {
            zos.write(buffer, 0, len);
        }

        in.close();
        zos.closeEntry();

        //remember close it
        zos.close();

        System.out.println("Done");

    }catch(IOException ex){
       ex.printStackTrace();
    }
}

我可以在fileoutputstream这里提供什么？内容文件和导航文件是我从代码中创建的文件。

Answer 1

试试这个：

@RequestMapping(value="download", method=RequestMethod.GET)
public void getDownload(HttpServletResponse response) {

    // Get your file stream from wherever.
    InputStream myStream = someClass.returnFile();

    // Set the content type and attachment header.
    response.addHeader("Content-disposition", "attachment;filename=myfilename.txt");
    response.setContentType("txt/plain");

    // Copy the stream to the response's output stream.
    IOUtils.copy(myStream, response.getOutputStream());
    response.flushBuffer();
}

参考

Answer 2

如果您的服务器是一个servlet容器，只需编写一个HttpServlet，它将压缩并提供文件。

您可以将servlet响应的输出流传递给ZipOutputStream的构造函数，zip文件将作为servlet响应发送：

ZipOutputStream zos = new ZipOutputStream(response.getOutputStream());

在压缩之前，不要忘记设置响应mime类型，例如：

response.setContentType("application/zip");

整体情况：

public class DownloadServlet extends HttpServlet {

    @Override
    public void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException {
        response.setContentType("application/zip");
        response.setHeader("Content-Disposition", "attachment; filename=data.zip");

        // You might also wanna disable caching the response
        // here by setting other headers...

        try ( ZipOutputStream zos = new ZipOutputStream(response.getOutputStream()) ) {
            // Add zip entries you want to include in the zip file
        }
    }
}