Question

我需要从android设备向Servlet发送一些字节数组。为此，我尝试使用下一个代码：

的Servlet

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws 
ServletException, IOException {

  DataInputStream in = new DataInputStream((InputStream)request.getInputStream());
   response.setContentType("text/plain");
    byte[] buffer = new byte[1024];
    int len = 0;
    File file;
    file=new File(getServletContext().getRealPath("/POST_LOG!!!!.txt"));
    if(!file.exists()){
        file.createNewFile();
    }
    while ((len = in.read(buffer)) > 0) {
          FileOutputStream fos = new FileOutputStream(getServletContext().getRealPath("/POST_LOG!!!!.txt"), true);

           fos.write(buffer);            
           fos.close(); 
    }

    PrintWriter out = response.getWriter();
    out.write("Done");
    out.close();

设备端：

URL uploadUrl;
    try {
        uploadUrl = new URL(url);
        HttpURLConnection c = (HttpURLConnection) uploadUrl
                .openConnection();
        c.setRequestMethod("POST");

        c.setDoInput(true);
        c.setDoOutput(true);
        c.setUseCaches(false);
        c.connect();
        OutputStream out = c.getOutputStream();

        for (int i = 0; i < 1000; i++) { // generate random bytes for
                                            // uploading
            byte[] buffer = new byte[256];
            for (int j = 0; j < 256; j++) {
                Random r = new Random();
                buffer[j] = (byte) r.nextInt();
            }

            out.write(buffer);
            out.flush();
        }

        out.close();

    } catch (Exception e) {
        MessageBox("Error. " + e.toString());
    }

    return (long) 0;
}

我不明白为什么这段代码不起作用。当我尝试调试我的POST方法时，它甚至没有调用。我将感谢你的例子

Answer 1

我找到了解决方案。我刚刚使用自定义InputStream更改了设备端代码。

设备端：

HttpPost httpPost = new HttpPost(url);
    httpPost.setEntity(new InputStreamEntity(new MyInputStream(),
            4096 * 1024 * 10));
    HttpResponse response = null;

    try {
        response = httpClient.execute(httpPost);
    } catch (ClientProtocolException e) {
        e.printStackTrace();
        httpPost.abort();
    } catch (IOException e) {
        e.printStackTrace();
        httpPost.abort();
    }

Answer 2

你有很多选择：

发送字节值：125,11,25,40（这是一个愚蠢的选项）
发送base64-或hex-encoded，然后对其进行解码（使用apache commons-codec）
以multipart/form-data

如何将字节数组从Android设备发送到servlet

2 个答案: