nodejs给文件链接添加md5

点点

2021-05-05 10:22 阅读 359 喜欢 0

因为没有用到webpack ，是java项目，所以准备做一个小工具，检索jsp或html中引用css js的地方，并根据对应的路径找到文件，对文件进行md5计算，最后给链接更新一个md5值，这样没有变化的就会缓存，有变化的就会从服务器更新。

大体思路

1.检索目标目录下的jsp 或 html 2.读取内容，根据正则找到 link 或 script 3.根据规则，找到对应的目录的文件 4.读取文件，计算MD5 5.更新回原来的地址 6.结束

代码实现

准备使用nodejs 来实现。

    //给jsp 或 html 中的css js 添加fileMd5值
    var fs = require('fs'),
readline = require('readline'),
path = require('path'),
join = path.join,
extname = path.extname,
async = require('async'),
colors = require('colors'),
url = require('url'),
crypto = require('crypto'),
qs = require('querystring');

    function AddMd5(directory,opts){
this.directory = directory;
this.fileList = [];
this.count = 0;
this.extList = opts.extList;//['.jsp','.html','.htm'];
this.exclude = opts.exclude;//['plugins'];
this.compress = opts.compress;
this.replace = opts.replace;//['${basepath}','${staticresdomain}','<%=basepath%>'];//替换字符串
return this;
 }
   //获得符合条件的文件
    AddMd5.prototype.getFiles = function(dirPath){
var thiz = this;
if(fs.existsSync(dirPath)){
    var files = fs.readdirSync(dirPath);
    if(files && files.length > 0){
        for(var i=0,max=files.length;i<max;i++){
            var temp = files[i];
            var filePath = join(dirPath,temp);
            var stats = fs.statSync(filePath);
            if(stats.isDirectory() && thiz.exclude.indexOf(temp) < 0){
                //继续
                thiz.getFiles(filePath);
            }else{
                var fileExt = extname(filePath).toLowerCase();
                if(thiz.extList.indexOf(fileExt) > -1){
                    //符合
                    thiz.fileList.push(filePath);
                }
            }
        }
    }
}
}
  AddMd5.prototype.start = function(){
var thiz = this,
    directory = thiz.directory;
thiz.getFiles(directory);
console.log('共计扫描到 '.green+(''+thiz.fileList.length).red+' 个符合条件的文件'.green);
async.mapLimit(thiz.fileList,5,function(item,cb){
    thiz.scan(item,cb);
},function(err,value){
    console.log('共计替换 '.green+(''+thiz.count).red +' 个链接'.green)
});
};

    AddMd5.prototype.scan = function(filePath,callback){
var thiz = this,compress = thiz.compress;
var is = fs.createReadStream(filePath);
var inter = readline.createInterface({input :is});
var strArr = '';
inter.on('line',function(line){
    var rst = thiz.checkLine(line);
    if(rst){//检查到有内容
        //处理并替换
        var type = rst.type;
        var md5 = rst.md5;
        //检索并替换
        var arr = /src[\s]*=[\s]*[\"\']?([^\'\"]*)[\'\"]?/i.exec(line);
        if(arr && arr.length > 0){
            var src = arr[1];
            var query = url.parse(src).query;
            var src2 = src.indexOf('?') > -1 ? src.substring(0,src.indexOf('?')) : src;
            var qsObj = qs.parse(query);
            qsObj.v = md5.substring(0,5);
            var qsStr = qs.stringify(qsObj);
            var newSrc= src2 + '?'+qsStr;
            line = line.replace(src,newSrc);
            console.log('替换 [ '.green+line.red+' ]'.green);
            thiz.count ++ ;
        }
    }
    strArr+=line+(compress ? '' : '\n');
});
inter.on('close',function(){
    //重新写入
    fs.writeFileSync(filePath,strArr);
    callback(null,null);
})
 };
     //根据文件路径获得FILEMD5
     AddMd5.prototype.getMd5 = function(filePath){
var buffer = fs.readFileSync(filePath);
var md5 = crypto.createHash('md5');
md5.update(buffer);
return md5.digest('hex').toLowerCase();
   };
     AddMd5.prototype.checkLine = function(str){
//检查字符串是否符合 link script 
var thiz = this,replace = thiz.replace,directory = thiz.directory;
str = str.toLowerCase().replace(/\s/g,'');
var rst = /\<script[\s\S]*src="([\$\{\}\w\.\/\<\%\=\>\?\&]*)"[\s\S]*\>[\s\S]*\<\/script\>/g.exec(str);
var src = '';
var type = '';
if(rst && rst.length > 0){
    src = rst[1];
    type = 'src';
}
rst = /^\<link[\s\S]*href="([\$\{\}\w\.\/\<\%\=\>\?\&]*)"[\s\S]*[\>|\/\>|\<\/link\>]$/g.exec(str);
if(rst && rst.length > 0 && rst[1].indexOf('favicon') < 0){
    src = rst[1];
    type = 'href';
}
if(src){
    if(replace && replace.length > 0){
        for(var i=0,max=replace.length;i<max;i++){
            src = src.replace(replace[i],'');
        }
    }
    var srcObj = url.parse(src);
    var query = srcObj.query;
    var filePath = join(directory,srcObj.pathname);
    if(fs.existsSync(filePath)){
        var fileMd5 = thiz.getMd5(filePath);
        return {
            md5 : fileMd5,
            query : query,
            filePath : srcObj.pathname,
            type : type
        };
    }
}
return null;
 };

 module.exports = AddMd5;

封装了一个命令行工具，以后就可以随意对某个目录进行压缩啦，发布后自己安装下就可以啦。