通过nodejs将文件上传到mongodb

zz775520666

　　刚接触nodejs，有点犯晕...
　　这里要用到一些组件，通过npm安装一下 gridform和gridfs-stream
　　上传POST到 ：http://yourUrl/upload
　　上传后的文件，可以通过文件名和ID来访问，比如：http://yourUrl/id/xxxxxx  OR http://yourUrl/filename
　　
　　建好下面这两个文件后，运行node test.js启动



//test.js
var mongo = require('mongodb'),
FileServer=require('./fileserver'),
Server = require('mongodb').Server;
var db = new mongo.Db('test', new Server("127.0.0.1", 27017,{auto_reconnect:true}));
var fileServer = FileServer(db);
fileServer.start(8888);

　　
　　
　　



//fileserver.js
var http = require("http"),
url = require("url"),
mongo = require('mongodb'),
path = require("path"),
ObjectID = require('mongodb').ObjectID,
Grid = require('gridfs-stream'),
gridform = require('gridform'),
fs = require("fs"),
GridStore = require('mongodb').GridStore;

function FileServer(db) {
if (!(this instanceof FileServer)) return new FileServer(db);
this.db = db;
}
FileServer.prototype.start = function start(listenport) {
var me = this;
me.db.open(function(err) {
if (err) {
console.log(err);
return;
}
app.listen(listenport, "127.0.0.1");
console.log("Server running at http://127.0.0.1:" + listenport);
});
var app = http.createServer(function(req, res) {
var pathname = url.parse(req.url).pathname;
//upload////////////////////////////////////////////////////
if (pathname.indexOf('/upload') >= 0 && 'POST' == req.method) {
gridform.db = me.db;
gridform.mongo = mongo;
var outObj;
var form = gridform();
form.parse(req, function(err, fields, files) {
if (err) {
outObj = {
"status": 0,
"message": err
}
} else {
for (var obj in files) {
outObj = {
status: 1,
data: {
name: files[obj].name,
id: files[obj].id.toString(),
url: 'http://' + req.headers.host + '/id/' + files[obj].id.toString()
}
};
}
}
console.log('received upload..');
me.responMsg(res, 200, JSON.stringify(outObj));
});
} else if (pathname != '/') { //download///////////////////////////////////////
var filename, fileId, delPos, idPos, strId;
delPos = pathname.indexOf('/delete/');
idPos = pathname.indexOf('/id/');
//通过ID匹配文件
if (idPos >= 0) {
strId = pathname.substr(idPos + 4, pathname.length - idPos + 1);
filename = {
_id: strId
};
fileId = ObjectID(strId);
} else {
filename = pathname.replace('/', '');
}
console.log('get file:' + filename);
//优先查找磁盘中的文件
var realPath = "files" + pathname;

path.exists(realPath, function(exists) {
if (exists) {
fs.readFile(realPath, "binary", function(err, file) {
if (err) {
me.responMsg(res, 500, err);
} else {
var ext = path.extname(realPath);
ext = ext ? ext.slice(1) : 'unknown';
var contentType = mime[ext] || "text/plain";
res.writeHead(200, {
'Content-Type': contentType
});
res.write(file, "binary");
res.end();
}
});
} else {
// Verify that the file exists
me.exist(me.db, fileId || filename, function(err, result, item) {
if (!result) {
me.responMsg(res, 404, "文件不存在");
return;
}
if (delPos >= 0) {
GridStore.unlink(me.db, item._id, function(err) {
me.responMsg(res, 200, 'success')
});
} else {
var gfs = Grid(me.db, mongo);
var readstream = gfs.createReadStream(filename);
var ext = item.filename.split('.');
ext = ext ? ext[ext.length-1] : 'unknown';
var contentType = mime[ext] || "text/plain";
res.setHeader("Content-Type", contentType);
readstream.pipe(res);
}
});
}
});
} else {
res.setHeader("Content-Type", "text/html");
res.end(
'' + '' + '' + '');
}

});
}
FileServer.prototype.responMsg = function responMsg(response, status, msg) {
response.writeHead(status, {
'Content-Type': 'text/plain;charset=utf-8'
});
response.end(msg);
}
//覆盖了驱动里原始的exist方法，将找到的item也返回来
FileServer.prototype.exist = function exist(db, fileIdObject, rootCollection, callback) {
var args = Array.prototype.slice.call(arguments, 2);
callback = args.pop();
rootCollection = args.length ? args.shift() : null;
// Fetch collection
var rootCollectionFinal = rootCollection != null ? rootCollection : GridStore.DEFAULT_ROOT_COLLECTION;
db.collection(rootCollectionFinal + ".files", function(err, collection) {
// Build query
var query = (typeof fileIdObject == 'string' || Object.prototype.toString.call(fileIdObject) == '[object RegExp]') ? {
'filename': fileIdObject
} : {
'_id': fileIdObject
}; // Attempt to locate file
collection.find(query, function(err, cursor) {
cursor.nextObject(function(err, item) {
callback(null, item == null ? false : true, item);
});
});
});
};
var mime = {
"css": "text/css",
"gif": "image/gif",
"html": "text/html",
"ico": "image/x-icon",
"jpeg": "image/jpeg",
"jpg": "image/jpeg",
"js": "text/javascript",
"json": "application/json",
"pdf": "application/pdf",
"png": "image/png",
"svg": "image/svg+xml",
"swf": "application/x-shockwave-flash",
"tiff": "image/tiff",
"txt": "text/plain",
"wav": "audio/x-wav",
"wma": "audio/x-ms-wma",
"wmv": "video/x-ms-wmv",
"xml": "text/xml",
"doc": "application/msword",
"docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
"xls": "application/vnd.ms-excel",
"xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
};
module.exports = exports = FileServer;