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Ruby:多线程下载博客文章到本地的完整代码#encoding:utf-8 require 'net/http' require 'thread' require 'open-uri' require 'nokogiri' require 'date' $queue = Queue.new #文章列表页数 page_nums = 8 page_nums.times do |num| $queue.push("http://www.cnblogs.com/hongfei/default.html?page="+num.to_s) end threads = [] #获取网页源码 def get_html(url) html = "" open(url) do |f| html = f.read end return html end def fetch_links(html) doc = Nokogiri::HTML(html) #提取文章链接 doc.xpath('//div[@class="postTitle"]/a').each do |link| href = link['href'].to_s if href.include?"html" #add work to the queue $queue.push(link['href']) end end end def save_to(save_to,content) f = File.new("./"+save_to+".html","w+") f.write(content) f.close() end #程序开始的时间 $total_time_begin = Time.now.to_i #开辟的线程数 threadNums = 10 threadNums.times do threads<<Thread.new do until $queue.empty? url = $queue.pop(true) rescue nil html = get_html(url) fetch_links(html) if !url.include?"?page" title = Nokogiri::HTML(html).css('title').text puts "["+ Time.now.strftime("%H:%M:%S") + "]「" + title + "」" + url save_to("pages/" + title.gsub(/\//,""),html) if url.include?".html" end end end end threads.each{|t| t.join} #程序结束的时间 $total_time_end = Time.now.to_i puts "线程数:" + threadNums.to_s puts "执行时间:" + ($total_time_end - $total_time_begin).to_s + "秒" 多线程部分讲解$queue = Queue.new #文章列表页数 page_nums = 8 page_nums.times do |num| $queue.push("http://www.cnblogs.com/hongfei/default.html?page="+num.to_s) end
首先声明一个Queue队列,然后往队列中添加文章列表页,以便后面可以从这些列表页中提取文章链接,另外queue声明成全局变量($),以便在函数中也可以访问到 #开辟的线程数 threadNums = 10 threadNums.times do threads<<Thread.new do until $queue.empty? url = $queue.pop(true) rescue nil html = get_html(url) fetch_links(html) if !url.include?"?page" title = Nokogiri::HTML(html).css('title').text puts "["+ Time.now.strftime("%H:%M:%S") + "]「" + title + "」" + url save_to("pages/" + title.gsub(/\//,""),html) if url.include?".html" end end end end threads.each{|t| t.join}
通过Thread.new来创建线程 代码执行时间统计#程序开始的时间 $total_time_begin = Time.now.to_i #执行过程 #程序结束的时间 $total_time_end = Time.now.to_i puts "执行时间:" + ($total_time_end - $total_time_begin).to_s + "秒" TIme模块的#now方法可以获取当前时间,然后使用to_i,可以将当前时间转换成从1970年1月1日00:00:00 UTC开始所经过的秒数。 获取网页源码#获取网页源码 def get_html(url) html = "" open(url) do |f| html = f.read end return html end ruby中,获取网页的方法用Net::HTTP模块和OpenURI模块。OpenURI模块最简单,可以直径将指定网页当成普通文件一样进行操作。 执行结果:使用多线程采集130多篇文章,耗时15秒(单线程:47s左右)
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