从网络驱动器打开文件

Question

@WebServlet(name="fileHandler", urlPatterns={"/fileHandler/*"})
public class FileServlet extends HttpServlet 
{
  private static final int DEFAULT_BUFFER_SIZE = 10240; // 10KB.
  ...
  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    String requestedFile = request.getPathInfo();
    ...
    File file = new File("G:/test_dir", URLDecoder.decode(requestedFile, "UTF-8")); // cesta se nacita v kazdem doGet
    String contentType = getServletContext().getMimeType(file.getName());

    response.reset();
    response.setBufferSize(DEFAULT_BUFFER_SIZE);
    response.setContentType(contentType);
    response.setHeader("Content-Length", String.valueOf(file.length()));
    response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");
    BufferedInputStream input = null;
    BufferedOutputStream output = null;

    try 
    {
      input = new BufferedInputStream(new FileInputStream(file), DEFAULT_BUFFER_SIZE);
      output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);
      byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
      int length;
      while ((length = input.read(buffer)) > 0) 
      {
        output.write(buffer, 0, length);
      }
    } 
    finally 
    { 
      close(output);
      close(input);
    }
  }
}

<a href="fileHandler/test.txt">TEST FILE</a>

public class Test 
{
  static void main(String[] args) 
  {
    String path = "G:/test_dir/test.txt";
    File file = new File(path);
    System.err.println(file.exists() ? "OK" : "NOK");
  }
} 

我尝试过不同的URI方案：

• g://test_dir
• g:\\test_dir

以下内容根本不起作用：

null

null

Answer 1

如果您可以调试服务器并查看日志，请尝试以下操作：

String requestedFile = request.getPathInfo();
log.debug('requestedFile='+requestedFile);
String decodedFilename = URLDecoder.decode(requestedFile, "UTF-8");
log.debug('decodedFilename='+decodedFilename);


File dir = new File("G:/test_dir");
log.debug('File g:/test_dir is a dir:'+dir.isDirectory());

File file = new File(dir, decodedFilename);
log.debug('requested file = '+file.getAbsolutePath());
log.debug('file exists = '+file.isFile());

如果没有设置日志框架，可以使用system.out.println()代替log.debug()，但不建议在生产中使用。

这不会解决你的问题，但你可以看到发生了什么。