Question

嘿，我正在写一个应用程序。我要求客户端输入某些消息，具体取决于我从服务器向客户端发送数据时收到的消息。当用户从客户端输入数据时，会发生响应，客户端再打印一次“输入消息”...我正在使用node.js的readline和net模块。这是我的代码：

var server = net.createServer(   //My server side code which sends response.
function(socket){
    console.log("Client connection...");


    socket.on('end', function(){
        console.log("Client disconnected...");

    });

    socket.on('data', function(data){
        console.log(" Received: ", data.toString());

        a=data.toString();

        if(a=="lookupByLastName Smith") //json data send if client sends this
        {
            arr= employees.lookupByLastName('Smith');
            socket.write("Data"+JSON.stringify(arr));
        }




    });

    socket.write("Hello from server");
});

//客户端代码：

 var rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
 });

var readMessage = function(client) {
        rl.question("Enter Message: ", function (line){
        client.write(line);//enter message appears twice before server res.                    
        if (line == "bye")
            client.end();
        else
            readMessage(client);
   });
};

 var client = net.connect({port:3000},
   function(){
      console.log("Connected to server");
      readMessage(client);
    });

client.on('end', function(){
    console.log("Client disconnected...");
    return;
  });

  client.on('data', function(data){
   console.log("\n --Received:", data.toString());  
 });

Check the second message "Enter message" it shouldn't appear second time till server responds back。解决问题需要帮助。

Answer 1

您可以在从服务器收到数据时询问用户输入。

在下面的示例中，我还为服务器问候消息添加了一些超时，以及当服务器没有响应客户端消息4秒时：

var readline = require('readline');
var net = require('net');

var port = 3000;

var helloTimeout;
var responseTimeout;
var timeout = 4000;

var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

var readMessage = function(client) {
    rl.question("Enter Message: ", function(line) {
        client.write(line); //enter message appears twice before server res.                    
        if (line == "bye") {
            client.end();
        } else {
            responseTimeout = setTimeout(function() {
                console.log('not response from server for ' + timeout + "ms");
                client.emit("wait_for_input");
            }, timeout);
        }
    });
};

var client = net.connect({ port: port },
    function() {
        console.log("Connected to server");
        helloTimeout = setTimeout(function() {
            console.log('no hello received for ' + timeout + "ms, closing ...");
            client.end();
        }, timeout);
    });

client.on('end', function() {
    console.log("Client disconnected...");
    rl.close();
});

client.on('wait_for_input', function() {
    readMessage(client);
});

client.on('data', function(data) {
    clearTimeout(helloTimeout);
    clearTimeout(responseTimeout);
    console.log("\n --Received:", data.toString());
    client.emit("wait_for_input");
});

我创建了一个名为client的{{1}}的另一个事件，只有在数据来自服务器（计算此数据之后）并且客户端没有收到服务器响应超过4秒后才会触发用户输入一些命令后

在让客户端输入另一条消息之前等待服务器响应

1 个答案: