Question

我正在尝试从网址example.com获取json数据，并将其传递给我的index.html。我怎样才能做到这一点。没用我想每5秒更新一次文件index.html的数据。 app.js

int ws_dissect_init(void) {
    epan_register_plugin_types(); /* Types known to libwireshark */
    scan_plugins(REPORT_LOAD_FAILURE);
    if (!epan_init(register_all_protocols, register_all_protocol_handoffs, NULL, NULL)) {
        /*fprintf(stderr, "Error at epan_init\n");*/
        return 2;
    }

    /*set_disabled_protos_list();*/
    // TODO: this one here closes stdin for whatever reason, y tho?
    proto_initialize_all_prefixes();
    //FIXME: do this properly
#if _WIN32
#else
    freopen("/dev/tty", "r", stdin);
#endif

    dissect_initialized = TRUE;
    return 0;
}

ws_dissect_t *ws_dissect_capture(ws_capture_t *capture) {
    epan_free(capture->cfile.epan);
    capture->cfile.epan = tshark_epan_new(&capture->cfile);
    ws_dissect_t *handle = g_malloc0(sizeof *handle);
    handle->cap = capture;
    return handle;
}

void ws_dissect_finalize(void) {
    // crashes, but we only call this at exit time
    // So it's no big deal (TM)
    /*epan_cleanup();*/
    dissect_initialized = FALSE;
}

index.html

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var https = require('https');

app.get('/', function(req, res) {
   res.sendfile('index.html');
   //How to use req object ?

});

io.on('connection', function(socket) {
   console.log('A user connected');


   setInterval(function() {
    urlString = "https://example.com/trip?trip_id=1234";

        $.get(urlString, function(data, status){
            console.log('data');
         })

   socket.send('');
   }, 4000);

   socket.on('disconnect', function () {
      console.log('A user disconnected');
   });
});

http.listen(3000, function() {
   console.log('listening on *:3000');
});

Answer 1

您做错了很多事情：

$.get()未在服务器上运行。那是客户端jQuery代码
您应该在服务器上创建一个setInterval()，而不是为每个客户端连接创建一个新的
然后您可以将结果广播到所有连接的客户端
如果您在页面加载后document.write()在客户端中，它将仅清除原始文档，因此您想将信息附加到DOM，而不使用document.write()。
使用socket.io发送数据时，将发送消息名称和一些数据.emit(someMessage, someData)。

这是编写代码的一种方法：

// server.js
const app = require('express')();
const server = require('http').Server(app);
const io = require('socket.io')(server);
const request = require('request');


app.get('/', function(req, res) {
   res.sendfile('index.html');
});

// create one and only one interval
setInterval(function() {
  let urlString = "https://example.com/trip?trip_id=1234";

  request(urlString, function(err, response, data) {
    if (err) {
      console.log("error on request", err);
    } else {
      console.log('data');
      // send to all connected clients
      io.emit('message', data);
    }
  });

}, 5000);

io.on('connection', function(socket) {
  console.log('A user connected');

  socket.on('disconnect', function () {
      console.log('A user disconnected');
  });
});

server.listen(3000, function() {
   console.log('listening on *:3000');
});


// index.html
<script src="/socket.io/socket.io.js"></script>
<script>
var socket = io();
socket.on('message', function(data){
  let div = document.createElement("div");
  div.innerHTML = data;
  document.body.appendChild(div);
});
</script>

如何在socket.io中请求URL

1 个答案: