java - WebSocket 握手错误：意外的响应代码：400

Question

我必须在我的项目中使用engine.io-server-java。当我启动eio函数时，请求失败并抛出 400 Bad requests。我该如何调试这个问题？是否有可用于 engine.io-server-java 的文档？

错误

WebSocket 连接到“ws://localhost:8080/engine.io/?EIO=3&transport=websocket&sid=Mg_ZSd5”失败：WebSocket 握手期间出错：意外响应代码：400

请求标头

代码：

@WebServlet("/engine.io/*")
public class SocketIO extends HttpServlet {
    private final EngineIoServer server = new EngineIoServer();

    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws IOException {
        server.handleRequest(request, response);
        server.on("connection", new Emitter.Listener() {
            @Override
            public void call(Object... arg0) {
                System.out.println("Socket connected");         
            }
        });
    }
}

客户代码：

var io = eio("http://localhost:8080", {transport: ["websocket"], upgrade: true, reconnection: false});