Question

我使用ebay-api作为node-js，当我因某种原因刷新页面时出现错误。在控制台日志中，我收到了错误＃34;发送后不能发送标题。＆＃34; 这是我的代码，你能弄清楚为什么我会在发送标题后发送标题＆＃34;当我刷新？

// example simple request to FindingService:findItemsByKeywords

var ebay = require('../index.js');
var http = require('http');

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


app.set('port', process.env.PORT || 5000);

app.get('/getEbay', function (req, res) {
    console.log('inside get');
    //  for avoiding crossbrowser-error
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');
    res.header('Content-Type', 'application/json');
    var params = {};

    params.keywords = ["cat"];
    params['paginationInput.entriesPerPage'] = 10;
    ebay.ebayApiGetRequest({
        serviceName: 'FindingService',
        opType: 'findItemsByKeywords',
        appId: 'MYAPPID',      // FILL IN YOUR OWN APP KEY, GET ONE HERE: https://publisher.ebaypartnernetwork.com/PublisherToolsAPI
        params: params,
        // filters: filters,
        parser: ebay.parseItemsFromResponse    // (default)
    },
    // gets all the items together in a merged array
  function ebayApiGetRequest(error, items) {
      if (error) throw error;

      console.log('Found', items.length, 'items');
      //  res.send(items);
        console.log(JSON.stringify(items));


      res.contentType('application/json');

      res.send(JSON.stringify(items));

      //  }  
  }
);

});


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

console.log('Listening on port 5000...');

我认为我的错误是调用函数的顺序，或者可能有办法避免这种错误的调用？

Answer 1

而不是：

res.send(JSON.stringify(items));
res.send(items);

尝试：

res.end(JSON.stringify(items));

Answer 2

function ebayApiGetRequest(error, items) {
      if (error) throw error;

      console.log('Found', items.length, 'items');
      //  res.send(items);
        console.log(JSON.stringify(items));


      res.contentType('application/json');

      res.send(JSON.stringify(items));// you send here
      res.send(items);//and you send again right afterwards?

      //  }  
  }

如果您实际执行了两次发送，那么当然您将发送两次数据。其中一个res.send()就足够了。

Answer 3

好吧，伙计们，我们找出了问题！

这里有正在运行的新代码：

// example simple request to FindingService:findItemsByKeywords
var http = require('http');

var express = require('express');
var app = express();
var io = require('socket.io');
var ebay = require('../index.js');


app.set('port', process.env.PORT || 5000);

app.get('/getEbay', function(req, res) {
    console.log('inside get');
    //  for avoiding crossbrowser-error
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');
    res.header('Content-Type', 'application/json');

    getEbaybyResults(function(error, items) {
          if (error) throw error;

          console.log('Found', items.length, 'items');
          //  res.send(items);
          console.log(JSON.stringify(items));


        // res.contentType('application/json');
        //  console.log(try);
       // res.send(JSON.stringify(items));
        res.end(JSON.stringify(items));
    });


});

function getEbaybyResults(callback) {

   var params = {};

    params.keywords = ["cat"];
    params['paginationInput.entriesPerPage'] = 10;
    ebay.ebayApiGetRequest(
      {
        serviceName: 'FindingService',
        opType: 'findItemsByKeywords',
        appId: 'MYAPPID',      // FILL IN YOUR OWN APP KEY, GET ONE HERE: https://publisher.ebaypartnernetwork.com/PublisherToolsAPI
        params: params,
        // filters: filters,
        parser: ebay.parseItemsFromResponse    // (default)
      },
      function(error, items) {
        callback(error, items);
      }
    );
    //ebayApiGetRequest();
}

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

//console.log('Listening on port 5000...');

node js error - 发送后无法发送标头

3 个答案: