node-rest-client：发送后无法设置headers。

Question

我正在尝试使用 node-rest-client 从节点调用 REST API。如果我的调用 returns 出错，我想捕获错误并将其报告给调用者。

我正在用 Postman 尝试这个，不幸的是这只能工作一次。当我第二次按下发送时，我的 node.js 程序崩溃并出现错误 "Can't set headers after they are sent."

我是 node.js 的新人，非常感谢您的帮助！

//app stuff
const client_id = "x";
const client_secret = "y";
const callback = "https://myurl;

// Basic Setup
var http     = require('http'),
    express  = require('express'),
    mysql    = require('mysql'),
    parser   = require('body-parser'),
    Client   = require('node-rest-client').Client;

var client = new Client();

// Setup express
var app = express();
app.use(parser.json());
app.use(parser.urlencoded({ extended: true }));
app.set('port', process.env.PORT || 5000);

// Set default route
app.get('/', function (req, res) {
    res.send('<html><body><p>Welcome to Bank API Wrapper</p></body></html>');
});

app.post('/authorize', function (req,res) {
    var response = [];

    if (typeof req.body.code !== 'undefined' && typeof req.body.state !== 'undefined' ){
        var code = req.body.code, state = req.body.state;

        //conversion to base64 because citi api wants it this way
        var authorization = "Basic " + Buffer.from(client_id + ":" + client_secret).toString('base64');

        var args = {
            data:{"grant_type":"authorization_code","code":code,"redirect_uri":callback},
            headers:{"Authorization":authorization,"Content-Type":"application/x-www-form-urlencoded"} 
        };

        //get access and refresh token
        client.post("https://sandbox.apihub.citi.com/gcb/api/authCode/oauth2/token/sg/gcb", args, function (citidata, citiresponse) {
            //console.log(citidata);
            //console.log(citiresponse);
        });

        client.on('error', function (err) {
            response.push({'result' : 'error', 'msg' : 'unauthorized access'});
            res.setHeader('Content-Type', 'application/json');
            res.status(200).send(JSON.stringify(response));
        });
    } 
    else {
        response.push({'result' : 'error', 'msg' : 'Please fill required details'});
        res.setHeader('Content-Type', 'application/json');
        res.status(200).send(JSON.stringify(response));
    }
});


// Create server
http.createServer(app).listen(app.get('port'), function(){
    console.log('Server listening on port ' + app.get('port'));
});

Answer 1

你得到了这个：

client.on('error', function (err) {

这会在 client 上注册一个错误处理程序，但它永远不会被删除。 client 在请求之间共享，因此后续请求中的任何错误仍将触发旧的错误处理程序。

相反，您可以侦听请求中的错误。像这样：

var request = client.post("...

request.on('error', function(err) {
    // handle error
});

见https://www.npmjs.com/package/node-rest-client#error-handling

node-rest-client：发送后无法设置headers。

node-rest-client: Can't set headers after they are sent.

node.js

node-rest-client