我在使用 OKHttp3 时遇到了同样的问题.问题是我没有关闭每个请求的连接，并且对于客户端，相同的连接可用，而对于服务器则没有，因此服务器返回错误.

I had the same problem using OKHttp3. The problem was that I didn't close the connection for each request and for the client the same connection was available and for the server not, for this reason the server returns a error.

解决方案是指示每个请求在完成时关闭连接.您必须在标题中添加一个标志来表明这一点.在OKHttp3中是这样的:

The solution is indicating to each request to close the connection when it is finished. You have to add a flag in the header to indicate this. In OKHttp3 is like this:

Request request = new Request.Builder()
                             .url(URL)
                             .header("Connection", "close")
                             ...