Java servlet read a file and send it as response

问题

I'm trying to write a servlet which will read (download) file from a remote location and simply send it as response, acting more-or-less like a proxy to hide the actual file from getting downloaded. I'm from a PHP background where I can do it as simply as calling file_get_contents.

Any handy way to achieve this goal using servlet/jsp?

Thanks

回答1:

How about this one? FileUtils (Commons IO 2.5-SNAPSHOT API)

example /src_directory_path/ is mount directory of remote server.

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException {
    resp.setContentType("application/octet-stream");
    resp.setHeader("Content-Disposition", "filename=\"hoge.txt\"");
    File srcFile = new File("/src_directory_path/hoge.txt");
    FileUtils.copyFile(srcFile, resp.getOutputStream());
}

Was this by any chance what you wanted to hear?

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
  InputStream in = new URL( "http://remote.file.url" ).openStream();
  IOUtils.copy(in, response.getOutputStream());
}

回答2:

int BUFF_SIZE = 1024;
byte[] buffer = new byte[BUFF_SIZE];
File fileMp3 = new File("C:\Users\Ajay\*.mp3");
FileInputStream fis = new FileInputStream(fileMp3);
response.setContentType("audio/mpeg");
response.setHeader("Content-Disposition", "filename=\"hoge.txt\"");
response.setContentLength((int) fileMp3.length());
OutputStream os = response.getOutputStream();

try {
    int byteRead = 0;
    while ((byteRead = fis.read()) != -1) {
       os.write(buffer, 0, byteRead);

    }
    os.flush();
} catch (Exception excp) {
    downloadComplete = "-1";
    excp.printStackTrace();
} finally {
    os.close();
    fis.close();
}

来源：https://stackoverflow.com/questions/20342457/java-servlet-read-a-file-and-send-it-as-response

标签

java-ee