BufferedReader 未读取请求的 body

Question

我试图从 HttpPost 读取数据，但是当我从 BufferedReader 读取数据时，我只得到 header 信息。请看下面的代码。

这是服务器

try {
        ServerSocket server = new ServerSocket(8332);
        System.out.println("Listening for connection on port 8332 ....");
        while (true) {
            try (Socket socket = server.accept()) {
                BufferedReader buffer = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                String request = "";
                String line;
                while ((line = buffer.readLine()) != null) {
                    System.out.println(line);
                    request += line;
                }

                System.out.print("port 8332 reading: " + request);

            } catch (IOException e) {
                System.out.print(e.getMessage());
            }
        }
    } catch (IOException e){
        System.out.print(e.getMessage());
    }

这是客户

    HttpClient client = HttpClientBuilder.create().build();
    HttpPost post = new HttpPost("http://localhost:8332");

    try {
        StringEntity params =new StringEntity("details={\"name\":\"myname\",\"age\":\"20\"} ");
        post.addHeader("content-type", "application/x-www-form-urlencoded");
        post.setEntity(params);

        client.execute(post);
    } catch (IOException e){
        System.out.println(e);
    }

当我运行这个程序时，我得到以下输出

Listening for connection on port 8332 ....
POST / HTTP/1.1
content-type: application/x-www-form-urlencoded
Content-Length: 37
Host: localhost:8332
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.5.6 (Java/1.8.0_131)
Accept-Encoding: gzip,deflate

经过调试，程序似乎没有退出这个 while 循环

while ((line = buffer.readLine()) != null) {
                System.out.println(line);
                request += line;
            }

但我不明白为什么。请帮助我卡了一整天。

提前致谢

Answer 1

在 while 循环中使用 !=0 而不是 !=null：

while((line = buffer.readLine()).length() !=0) {

输出：

port 8332 reading: POST / HTTP/1.1content-type: application/x-www-form-urlencodedContent-Length: 18Host: localhost:8332Connection: Keep-AliveUser-Agent: Apache-HttpClient/4.5.3 (Java/1.8.0_171)Accept-Encoding: gzip,deflateorg.apache.http.NoHttpResponseException: localhost:8332 failed to respond

Answer 2

But I can't figure out why.

您的服务器从 buffer.readLine() 获得 null 的唯一方法是客户端关闭其套接字输出流。

问题是客户端试图保持连接...这意味着它不会关闭其套接字输出流。这意味着服务器需要尊重“content-length”header；即计算读取的字节数而不是查找 end-of-stream.

从根本上说，您的服务器端没有正确实施 HTTP 1.1 规范。

怎么办？

好吧我的建议是不要尝试从套接字开始实现HTTP。使用现有框架...或 Apache HttpComponents 库。

但如果您坚持这样做¹，请在开始尝试实施之前通读阅读 HTTP 规范。并在您运行遇到实施问题时随时查阅规范，以检查您是否在做正确的事情。

^{1 - 定义：受虐狂 - 享受看似痛苦或乏味的 activity。}

BufferedReader 未读取请求的 body

BufferedReader is not reading body of request

java

client

bufferedreader

server