MongoDbDemo.py

#encoding=utf-8

import StringIO
import threading

from pymongo import Connection
from gridfs import *
from PIL import Image
from bson.objectid import ObjectId


# 文件处理系统
class GFS:
    # 定义connection and fs
    c = None
    db = None
    fs = None
    instance = None
    locker = threading.Lock()

    @staticmethod
    def _connect():
        if not GFS.c:
            GFS.c = Connection("mongodb://127.0.0.1:27017")  # 建立mongodb的连接
            GFS.db = GFS.c['hw-sq']  # 连接到指定的数据库中
            GFS.fs = GridFS(GFS.db, collection='fs')  # 连接到具体的collection中

        # 初始化

    def __init__(self):
        print "__init__"
        GFS._connect()
        print "server info " + " * " * 40
        print GFS.c.server_info

    # 获得单列对象
    @staticmethod
    def getInstance():
        GFS.locker.acquire()
        try:
            GFS.instance
            if not GFS.instance:
                GFS.instance = GFS()
            return GFS.instance
        finally:
            GFS.locker.release()

        # 写入

    def put(self, name, format="png", mime="image"):
        gf = None
        data = None
        try:
            data = StringIO.StringIO()
            name = "%s.%s" % (name, format)
            image = Image.open(name)
            image.save(data, format)
            # print "name is %s=======data is %s" % (name, data.getvalue())
            gf = GFS.fs.put(data.getvalue(), filename=name, format=format)
        except Exception as e:
            print "Exception ==>> %s " % e
        finally:
            GFS.c = None
            GFS._connect()
            return gf

        # 获得图片

    def get(self, id):
        gf = None
        try:
            gf = GFS.fs.get(ObjectId(id))
            im = gf.read()  # read the data in the GridFS
            dic = {}
            dic["chunk_size"] = gf.chunk_size
            dic["metadata"] = gf.metadata
            dic["length"] = gf.length
            dic["upload_date"] = gf.upload_date
            dic["name"] = gf.name
            dic["content_type"] = gf.content_type
            dic["format"] = gf.format
            return (im, dic)
        except Exception, e:
            print e
            return (None, None)
        finally:
            if gf:
                gf.close()


    # 将gridFS中的图片文件写入硬盘
    def write_2_disk(self, data, dic):
        name = "./get_%s" % dic['name']
        if name:
            output = open(name, 'wb')
            output.write(data)
            output.close()
            print "fetch image ok!"


    # 获得文件列表
    def list(self):
        return GFS.fs.list()

    # 删除文件
    def remove(self, name):
        GFS.fs.remove(name)


if __name__ == '__main__':
    image_name = u'F:\gongxiang\lptp\济南楼盘\houses_type_pic\\2-221-90-A.jpg'
    if image_name:
        gfs = GFS.getInstance()
        if gfs:
            image_id = gfs.put(image_name)
            print "==========Object id is %s  and it's type is %s==========" % (image_id, type(image_id))
#(data, dic) = gfs.get(ObjectId(image_id))
# gfs.write_2_disk(data, dic)