//======================================================
// umei图片批量下载Node.js爬虫1.00
// 2017年11月13日
//======================================================// 内置http模块
var http=require("http");// 内置文件处理模块，用于创建目录和图片文件
var fs=require('fs');// cheerio模块，提供了类似jQuery的功能，用于从HTML code中查找图片地址和下一页
var cheerio = require("cheerio");// 请求参数JSON。http和https都有使用
var options;// request请求
var req;// 图片数组，找到的图片地址会放到这里
var pictures=[];//--------------------------------------
// 爬取网页，找图片地址，再爬
// pageUrl sample:http://www.umei.cc/meinvtupian/waiguomeinv/12667.htm
// pageUrl sample:http://www.umei.cc/meinvtupian/waiguomeinv/12667_3.htm
//--------------------------------------
function crawl(pageUrl){console.log("Current page="+pageUrl);// 得到hostname和pathvar currUrl=pageUrl.replace("http://","");var pos=currUrl.indexOf("/");var hostname=currUrl.slice(0,pos);        var path=currUrl.slice(pos);    //console.log("hostname="+hostname);//console.log("path="+path);// 初始化options  options={hostname:hostname,port:80,path:path,// 子路径method:'GET',};req=http.request(options,function(resp){resp.setEncoding('utf8');var body="";resp.on('data',function(chunk){body+=chunk;            });resp.on('end',function(){//console.log("body="+body);var $ = cheerio.load(body);        var picCount=0;// 找图片放入数组$(".ImageBody p img").each(function(index,element){var picUrl=$(element).attr("src");//console.log(picUrl);if(picUrl.indexOf('.jpg')!=-1){pictures.push(picUrl); picCount++;} })   console.log("找到图片"+picCount+"张.");var nextPageUrl=null;// 找下一页$(".NewPages ul li a").each(function(index,element){var text=$(element).text();if(text.indexOf('下一页')!=-1){nextPageUrl=$(element).attr("href");nextPageUrl="http://www.umei.cc/"+nextPageUrl;// 把省略部分加上console.log("找到下一页.");}        })if(nextPageUrl==null){console.log(pageUrl+"已经是最后一页了.");download(pictures);}else{//console.log("下一页是"+nextPageUrl);
                crawl(nextPageUrl);}});});// 超时处理req.setTimeout(10000,function(){req.abort();});// 出错处理req.on('error',function(err){if(err.code=="ECONNRESET"){console.log('[crawl]socket端口连接超时。');console.log(err);}else{console.log('请求发生错误，err.code:'+err.code);console.log(err);}});// 请求结束
    req.end();
}var total=0;
var succeed=0;
var failed=0;//--------------------------------------
// 下载图片
//--------------------------------------
function download(pictures){var folder='pictures('+getNowFormatDate()+")";// 创建目录fs.mkdir('./'+folder,function(err){if(err){console.log("目录"+folder+"已经存在");}});total=pictures.length;console.log("总计有"+total+"张图片将被下载.");appendToLogfile(folder,"总计有"+total+"张图片将被下载.\n");for(var i=0;i<pictures.length;i++){var picUrl=pictures[i];downloadPic(picUrl,folder);}
}//--------------------------------------
// 写log文件
//--------------------------------------
function appendToLogfile(folder,text){fs.appendFile('./'+folder+'/log.txt', text, function (err) {if(err){console.log("不能书写log文件");console.log(err);}});
}//--------------------------------------
// 取得当前时间
//--------------------------------------
function getNowFormatDate() {var date = new Date();var seperator1 = "-";var seperator2 = "_";var month = date.getMonth() + 1;var strDate = date.getDate();if (month >= 1 && month <= 9) {month = "0" + month;}if (strDate >= 0 && strDate <= 9) {strDate = "0" + strDate;}var currentdate =date.getFullYear() + seperator1 + month + seperator1 + strDate+ " " + date.getHours() + seperator2 + date.getMinutes()+ seperator2 + date.getSeconds();return currentdate;
}//--------------------------------------
// 下载单张图片
// picUrl sample:http://www.avbaike.net/wp-content/uploads/2016/08/108.jpg
//--------------------------------------
function downloadPic(picUrl,folder){console.log("图片:"+picUrl+"下载开始");// 得到hostname和pathvar currUrl=picUrl.replace("http://","");var pos=currUrl.indexOf("/");var hostname=currUrl.slice(0,pos);        var path=currUrl.slice(pos);    //console.log("hostname="+hostname);//console.log("path="+path);var picName=currUrl.slice(currUrl.lastIndexOf("/"));// 初始化options  options={hostname:hostname,port:80,path:path,// 子路径method:'GET',};req=http.request(options,function(resp){var imgData = "";resp.setEncoding("binary"); resp.on('data',function(chunk){imgData+=chunk;            });resp.on('end',function(){        // 创建文件var fileName="./"+folder+picName;fs.writeFile(fileName, imgData, "binary", function(err){if(err){console.log("[downloadPic]文件"+fileName+"下载失败.");console.log(err);appendToLogfile(folder,"文件"+fileName+"下载失败.\n");failed++;}else{console.log("文件"+fileName+"下载成功");succeed++;}});    });});// 超时处理req.setTimeout(7500,function(){req.abort();});// 出错处理req.on('error',function(err){if(err){console.log('[downloadPic]文件'+picUrl+"下载失败,"+'因为'+err);appendToLogfile(folder,"文件"+picUrl+"下载失败.\n");}failed++;});// 请求结束
    req.end();
}//--------------------------------------
// 程序入口
//--------------------------------------
function getInput(){process.stdout.write("\033[35m 请输入第一页URL:\033[039m");    //紫色
    process.stdin.resume();process.stdin.setEncoding('utf8');    process.stdin.on('data',function(text){process.stdin.end();// 退出输入状态        crawl(text.trim());// trim()是必须的！
    });
}// 调用getInput函数，程序开始
getInput();