Java Applet 411 内容长度

Question

我是 Java 新手。我写了一个带有 gui 的小程序，将结果(int w 和 int p)发送到服务器，我得到了“411 Length Required”错误。我究竟做错了什么？如何设置内容长度？

这是与服务器通信的方法:

public void sendPoints1(int w, int p){

    try {
        String url = "http://somename.com:309/api/Results";
        String charset = "UTF-8";
        String query = String.format("?key=%s&value=%s",
            URLEncoder.encode(String.valueOf(w), charset),
            URLEncoder.encode(String.valueOf(p), charset));
        String length = String.valueOf((url + query).getBytes("UTF-8").length);

        HttpURLConnection connection = (HttpURLConnection) new URL(url + query).openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Length", length);
        connection.connect();
        System.out.println("Responce Code:    " + connection.getResponseCode());
        System.out.println("Responce Message: " + connection.getResponseMessage());
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }

}

Answer 1

我不是 100% 确定您收到 411 错误代码的原因，但这可能与您没有通过 POST 发送任何内容有关。内容长度 header 应该是请求正文的字节长度。您正在将其设置为 url 的长度!

将请求更改为 GET 或将查询放入请求正文而不是放入 url 本身。如果您选择后者，请将内容长度设置为仅正文的长度。

public void sendPoints1(int w, int p){

    try {
        String url = "http://somename.com:309/api/Results";
        String charset = "UTF-8";
        String query = String.format("key=%s&value=%s",
            URLEncoder.encode(String.valueOf(w), charset),
            URLEncoder.encode(String.valueOf(p), charset));
        byte[] queryBytes = query.getBytes("UTF-8");
        String length = String.valueOf((url + query).getBytes("UTF-8").length);

        HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Length", length);
        OutputStream os = connection.getOutputStream();
        os.write(queryBytes);
        os.flush();
        connection.connect();
        System.out.println("Responce Code:    " + connection.getResponseCode());
        System.out.println("Responce Message: " + connection.getResponseMessage());
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }

}