这两天做了一个图片上传功能，很庆幸express 3.x版本文件上传及nodejs 1.0xx版本文件操作功能支持的很不错。 然后找社区有无现成代码例子，参考了 letonlife大神的例子，

前端(不能直接copy代码，直接转换html):

form method=“post” enctype=“multipart/form-data” action="/userimage_upload"

    div class="modal-body"

        input class="customfile-input" type="file" name="user_file"
    /div
    div class="modal-footer"
        button class="btn" data-dismiss="modal" aria-hidden="true"关闭/button
        button class="btn btn-primary" type="submit"上传/button
    /div
/form

后端(包括引用mongoose连接池全贴上来):

var status = require(’./…/status’); var mongoose = status.mongoose; var db = status.db; var Schema = mongoose.Schema;

var filter = require("./…/moudels/filter.js");

var Removes_userlogo = db.model(‘remove_user_logo’,new Schema({ innerdate:{type:Date, default: Date.now} ,update:{type:Date, default: Date.now} ,user:String ,name:String }));

// 移动文件需要使用fs模块 var fs = require(‘fs’); module.exports = function(app){

app.post('/userimage_upload',filter.authorize ,function(req,res){
     // 获得文件的临时路径
    var tmp_path = req.files.user_file.path;
    var target_file = './public/user/logo/'+req.session.name;
    var target_path = target_file+'/user';
    
    var newIname_arry = req.files.user_file.name.split('.');

    var tem_extension = newIname_arry[newIname_arry.length-1]; //后缀名

    fs.exists(target_file,function(exist){
        if(!exist){
            
            fs.mkdirSync(target_file);
        }
        fs.exists(target_path+'.'+tem_extension,function(exist){
            if(exist){
                fs.exists(target_file+"/remove",function(exist){
                    if(exist){
                        takefile(target_path,target_file,tmp_path,tem_extension,function(remove_name){
                            insertRemoves_userlogo(req,res,remove_name);
                            res.send({status:0}); 
                        });
                    }else{
                        fs.mkdirSync(target_file+"/remove");
                        takefile(target_path,target_file,tmp_path,tem_extension,function(remove_name){
                            insertRemoves_userlogo(req,res,remove_name);
                            res.send({status:0}); 
                        });
                    }

                });
                
            }else{
                // 移动文件
                fs.rename(tmp_path, target_path+'.'+tem_extension, function(err) {
                  if (err){
                           throw err;
                        res.send({status:1}); 
                    }              
                  fs.unlink(tmp_path, function() {
                     if (err) throw err;
                     
                     res.send({status:0});  //res.send('File uploaded to: ' + target_path + ' - ' + req.files.thumbnail.size + ' bytes');
                  });

                });
            }
        });
    });
    
    
    
});

};

//文件操作 具体操作 //保留文件地址 回收站文件夹地址 临时文件地址 临时文件后缀名 自定义回调函数 var takefile=function(target_path,target_file,tmp_path,tem_extension,func){ var now = new Date();

var rOption = {
  flags : 'r',
  encoding : null,
  mode : 0666
}

var wOption = {
  flags: 'a',
  encoding: null,
  mode: 0666   
}
var namefiles = fs.readdirSync(target_file);
var remove_extension = "";
for(i in namefiles){
    if(namefiles[i].indexOf("user.") == 0){
        var arr = namefiles[i].split(".");
        remove_extension = arr[arr.length-1];
        break;
    }
}
var remove_name = now.getFullYear() + "-" + (now.getMonth() + 1) + "-" + now.getDate() + 
    "  "+now.getHours()+"_"+now.getMinutes()+"_"+now.getSeconds()+"_"+now.getMilliseconds();
var old_file = fs.createReadStream(target_path+'.'+remove_extension,rOption);
var new_file = fs.createWriteStream(target_file+"/remove/"+ remove_name +"."+remove_extension,wOption);

old_file.on('data',function(data){
  new_file.write(data);
    
});

old_file.on('end',function(){
      
      new_file.end();
      fs.unlink(target_path+'.'+tem_extension,function(err){
        
    });
    
      // 移动文件
    fs.rename(tmp_path, target_path+'.'+tem_extension, function(err) {
      if (err){
               throw err;
            res.send({status:1}); 
        }              
      fs.unlink(tmp_path, function() {
         if (err) throw err;
         
         func(remove_name);
      });

    });
});

}

//remove数据库增加 var insertRemoves_userlogo = function(req,res,name){ var removes = new Removes_userlogo({user:req.session.name,name:name,innerdate:Date(),update:Date()}); removes.save(function(err){ if(err){ throw err; } }); }

在数据库处理跟发送send上采用了回调调用处理,经过严格测试完美通过。 请教社区大神:感觉nodeJS这些函数的异步运行及JS的回调使用不知道怎么运用更好？ 不过很赞叹JS回调语法的好用。