使用Node JS在Node JS上進行HTTP請求回調

Question

嗨，我正在嘗試使用回調方法通過http獲得響應。 但是我得到了很多信息，但沒有得到我的數據：

    Request {
  domain: null,
  _events: 
   { error: [Function: bound ],
     complete: [Function: bound ],
     pipe: [Function] },
  _eventsCount: 3,
  _maxListeners: undefined,
  uri: 
   Url {
     protocol: 'http:',
     slashes: true,
     auth: null,
     host: 'localhost',
     port: 80,
     hostname: 'localhost',
     hash: null,
     search: '?filter=route_short_name',
     query: 'filter=route_short_name',
     pathname: '/php-rest/api.php/routes',
     path: '/php-rest/api.php/routes?filter=route_short_name',
     href: 'http://localhost/php-rest/api.php/routes?filter=route_short_name' },
  callback: [Function],
  readable: true,
  writable: true,
  _qs: 
   Querystring {
     request: [Circular],
     lib: { formats: [Object], parse: [Function], stringify: [Function] },
     useQuerystring: undefined,
     parseOptions: {},
     stringifyOptions: {} },
  _auth: 
   Auth {
     request: [Circular],
     hasAuth: false,
     sentAuth: false,
     bearerToken: null,
     user: null,
     pass: null },
  _oauth: OAuth { request: [Circular], params: null },
  _multipart: 
   Multipart {
     request: [Circular],
     boundary: '9ab5d31f-9896-4fb9-8f89-47e5501e9342',
     chunked: false,
     body: null },
  _redirect: 
   Redirect {
     request: [Circular],
     followRedirect: true,
     followRedirects: true,
     followAllRedirects: false,
     followOriginalHttpMethod: false,
     allowRedirect: [Function],
     maxRedirects: 10,
     redirects: [],
     redirectsFollowed: 0,
     removeRefererHeader: false },
  _tunnel: 
   Tunnel {
     request: [Circular],
     proxyHeaderWhiteList: 
      [ 'accept',
        'accept-charset',
        'accept-encoding',
        'accept-language',
        'accept-ranges',
        'cache-control',
        'content-encoding',
        'content-language',
        'content-location',
        'content-md5',
        'content-range',
        'content-type',
        'connection',
        'date',
        'expect',
        'max-forwards',
        'pragma',
        'referer',
        'te',
        'user-agent',
        'via' ],
     proxyHeaderExclusiveList: [] },
  headers: { host: 'localhost' },
  setHeader: [Function],
  hasHeader: [Function],
  getHeader: [Function],
  removeHeader: [Function],
  method: 'GET',
  localAddress: undefined,
  pool: {},
  dests: [],
  __isRequestRequest: true,
  _callback: [Function],
  proxy: null,
  tunnel: false,
  setHost: true,
  originalCookieHeader: undefined,
  _disableCookies: true,
  _jar: undefined,
  port: 80,
  host: 'localhost',
  path: '/php-rest/api.php/routes?filter=route_short_name',
  httpModule: 
   { IncomingMessage: { [Function: IncomingMessage] super_: [Object] },
     METHODS: 
      [ 'ACL',
        'BIND',
        'CHECKOUT',
        'CONNECT',
        'COPY',
        'DELETE',
        'GET',
        'HEAD',
        'LINK',
        'LOCK',
        'M-SEARCH',
        'MERGE',
        'MKACTIVITY',
        'MKCALENDAR',
        'MKCOL',
        'MOVE',
        'NOTIFY',
        'OPTIONS',
        'PATCH',
        'POST',
        'PROPFIND',
        'PROPPATCH',
        'PURGE',
        'PUT',
        'REBIND',
        'REPORT',
        'SEARCH',
        'SUBSCRIBE',
        'TRACE',
        'UNBIND',
        'UNLINK',
        'UNLOCK',
        'UNSUBSCRIBE' ],
     OutgoingMessage: { [Function: OutgoingMessage] super_: [Object] },
     ServerResponse: { [Function: ServerResponse] super_: [Object] },
     STATUS_CODES: 
      { '100': 'Continue',
        '101': 'Switching Protocols',
        '102': 'Processing',
        '200': 'OK',
        '201': 'Created',
        '202': 'Accepted',
        '203': 'Non-Authoritative Information',
        '204': 'No Content',
        '205': 'Reset Content',
        '206': 'Partial Content',
        '207': 'Multi-Status',
        '208': 'Already Reported',
        '226': 'IM Used',
        '300': 'Multiple Choices',
        '301': 'Moved Permanently',
        '302': 'Found',
        '303': 'See Other',
        '304': 'Not Modified',
        '305': 'Use Proxy',
        '307': 'Temporary Redirect',
        '308': 'Permanent Redirect',
        '400': 'Bad Request',
        '401': 'Unauthorized',
        '402': 'Payment Required',
        '403': 'Forbidden',
        '404': 'Not Found',
        '405': 'Method Not Allowed',
        '406': 'Not Acceptable',
        '407': 'Proxy Authentication Required',
        '408': 'Request Timeout',
        '409': 'Conflict',
        '410': 'Gone',
        '411': 'Length Required',
        '412': 'Precondition Failed',
        '413': 'Payload Too Large',
        '414': 'URI Too Long',
        '415': 'Unsupported Media Type',
        '416': 'Range Not Satisfiable',
        '417': 'Expectation Failed',
        '418': 'I\'m a teapot',
        '421': 'Misdirected Request',
        '422': 'Unprocessable Entity',
        '423': 'Locked',
        '424': 'Failed Dependency',
        '425': 'Unordered Collection',
        '426': 'Upgrade Required',
        '428': 'Precondition Required',
        '429': 'Too Many Requests',
        '431': 'Request Header Fields Too Large',
        '451': 'Unavailable For Legal Reasons',
        '500': 'Internal Server Error',
        '501': 'Not Implemented',
        '502': 'Bad Gateway',
        '503': 'Service Unavailable',
        '504': 'Gateway Timeout',
        '505': 'HTTP Version Not Supported',
        '506': 'Variant Also Negotiates',
        '507': 'Insufficient Storage',
        '508': 'Loop Detected',
        '509': 'Bandwidth Limit Exceeded',
        '510': 'Not Extended',
        '511': 'Network Authentication Required' },
     Agent: { [Function: Agent] super_: [Object], defaultMaxSockets: Infinity },
     globalAgent: 
      Agent {
        domain: null,
        _events: [Object],
        _eventsCount: 1,
        _maxListeners: undefined,
        defaultPort: 80,
        protocol: 'http:',
        options: [Object],
        requests: {},
        sockets: {},
        freeSockets: {},
        keepAliveMsecs: 1000,
        keepAlive: false,
        maxSockets: Infinity,
        maxFreeSockets: 256 },
     ClientRequest: { [Function: ClientRequest] super_: [Object] },
     request: [Function],
     get: [Function],
     _connectionListener: [Function: connectionListener],
     Server: { [Function: Server] super_: [Object] },
     createServer: [Function],
     Client: [Function: deprecated],
     createClient: [Function: deprecated] },
  agentClass: 
   { [Function: Agent]
     super_: 
      { [Function: EventEmitter]
        EventEmitter: [Circular],
        usingDomains: false,
        defaultMaxListeners: [Getter/Setter],
        init: [Function],
        listenerCount: [Function] },
     defaultMaxSockets: Infinity },
  agent: 
   Agent {
     domain: null,
     _events: { free: [Function] },
     _eventsCount: 1,
     _maxListeners: undefined,
     defaultPort: 80,
     protocol: 'http:',
     options: { path: null },
     requests: {},
     sockets: {},
     freeSockets: {},
     keepAliveMsecs: 1000,
     keepAlive: false,
     maxSockets: Infinity,
     maxFreeSockets: 256 } }

我的Node JS代碼是：

 var http = require('http'); function getRoutes(callback){ var callback = request('http://localhost/php-rest/api.php/routes?filter=route_short_name', function(error, response, body, callback) { if (!error && response.statusCode == 200) { result = JSON.stringify(JSON.parse(body)); //console.log(result); //res.setHeader('Content-Type', 'application/json'); //res.send(result); return callback = result; } else { //res.end('Error: ' + error); return callback = error; } }); return callback; } app.get('/getRoutes', function(req, res) { var data = getRoutes(); console.log(data); //res.setHeader('Content-Type', 'application/json'); res.send(data); }); 

我想要回調（結果或錯誤的內容）。 如果有人可以幫助我，將不勝感激。

Answer 1

這就是您應該使用回調編寫函數的方式。 request模塊沒有回調參數，請參見此處 。

var http    = require('http');

function getRoutes(callback){
    request('http://localhost/php-rest/api.php/routes?filter=route_short_name', function(error, response, body) {
        if (!error && response.statusCode == 200) {
            result = JSON.stringify(JSON.parse(body));          
            return callback(result, false);
        } else {            
            return callback(null, error);;
        }
    });
}

app.get('/getRoutes', function(req, res) {

    getRoutes(function(err, data){ 
        if(err) return res.send(err);       
        res.send(data);
    });

});

Answer 2

您的代碼中存在回調問題。 我認為您應該學習如何使用回調。 這是為您提供的教程https://www.tutorialspoint.com/nodejs/nodejs_callbacks_concept.htm

    var http    = require('http');

    function getRoutes(callback){
        request('http://localhost/php-rest/api.php/routes?filter=route_short_name', function(error, response, body) {
            if (!error && response.statusCode == 200) {

                result = JSON.stringify(JSON.parse(body));

                return callback(null, result);
            } else {
                return callback(error, null);
            }
        });
    }

    app.get('/getRoutes', function(req, res) {

        getRoutes(function(err, data){
            if(!err){

                    res.send(data);
            }
            else{
                  res.send(err);
            }

        });

    });

Answer 3

您沒有正確執行回調（糟糕的即時通訊）

var request = require('request');

function getRoutes(callback){

    request('http://localhost/php-rest/api.php/routes?filter=route_short_name', (error, response, body) => {

        if (!error && response.statusCode == 200) {

            result = JSON.stringify(JSON.parse(body));

            callback(null, result);

        } else {

            callback(error, null);

        }
    });

};

app.get('/getRoutes', (req, res) => {

    getRoutes(function(err, data) {

        if (err) console.log('error', err)//error handling

        console.log(data);

    });

});