问如何解决无法在java中通过http读取客户端请求？

EN

public class simpleHTTPServer {

    public static void main(String[] args) throws IOException {
        HttpServer server = HttpServer.create(new InetSocketAddress(9090), 0);
        HttpContext context = server.createContext("/");
        context.setHandler(simpleHTTPServer::handleRequest);
        server.start();
    }

    private static void handleRequest(HttpExchange exchange) throws IOException {
       // URI requestURI = exchange.getRequestURI();
        printRequestInfo(exchange);
        System.out.println("sending command..");
        String response = "123456";
        exchange.sendResponseHeaders(200, response.getBytes().length);
        OutputStream os = exchange.getResponseBody();
        os.write(response.getBytes());
        os.close();
    }

    private static void printRequestInfo(HttpExchange exchange) {
        System.out.println("-- headers --");
        Headers requestHeaders = exchange.getRequestHeaders();
        requestHeaders.entrySet().forEach(System.out::println);

        System.out.println("-- principle --");
        HttpPrincipal principal = exchange.getPrincipal();
        System.out.println(principal);

        System.out.println("-- HTTP method --");
        String requestMethod = exchange.getRequestMethod();
        System.out.println(requestMethod);

        System.out.println("-- query --");
        URI requestURI = exchange.getRequestURI();
        String query = requestURI.getQuery();
        System.out.println(query);
    }
}