node.js - "callback" argument must be a function
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问题描述
问 题
最后一句话报错,scraper()是一个爬虫函数,但是因为网站对请求频率有限制,所有要定时执行。
var request = require('request'),
cheerio = require('cheerio'),
http = require('http'),
url = require('url'),
mysql = require('mysql');
var id=22535;
var title;
var news = [];
function scraper (id) {
var host = 'http://www.sosobtc.com/article/'+id+".html";
request(host, function (error, response, data) {
if (!error && response.statusCode == 200) {
var $ = cheerio.load(data);
title = $('.article-header h2').text();
var time=$('.timestamp').first().text();
var content=$('.article-main').text();
var myDate=new Date();
//存入数据库
var connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '134679852a',
database:'news'
});
connection.connect();
//增加数据
var sql="insert into news(title,content,time) values(?,?,?)";
var sql_params=[title,content,myDate.toLocaleDateString()+'的'+time];
connection.query(sql,sql_params,function(err,result){
if(err){
console.log('[INSERT ERROR] - ',err.message);
return;
}
console.log("success !!! "+id);
});
//关闭连接
connection.end();
}
else console.log("page not found!"+id);
});
id--;
}
if(id<10002) {
console.log("finished");
clearInterval(stopid);
}
var stopid=setInterval(scraper(id),100);
解决方案
var stopid=setInterval(scraper(id),100);
改成
var stopid=setInterval(scraper,100,id);
要不然,你这样写是没效果的
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