mini-Web业务逻辑及其实现 / Business Logic for mini-web Frame

mini-Web业务逻辑及其实现

为什么需要WSGI？

当服务器收到浏览器请求后， 需要判断请求的是静态资源还是动态资源。如果是静态，则直接返回静态页面给浏览器；如果是动态，则需要处理数据后返回给浏览器。由于要保证服务器长期稳定运行，通常处理数据的这部分功能需要独立出来，因此会用到应用程序框架。

另外，为了不同web服务器和不同web框架之间的通配性以及可移植性，因此需要遵循WSGI(Web Server Gateway Interface，服务器网关接口)。 WSGI没有官方的实现，因为WSGI更像一个协议，遵循该协议的WSGI应用都可以在任何服务器上运行。

定义WSGI接口

我们只需要在web框架中定义一个符合WSGI标准的HTTP处理函数，即可响应HTTP请求。

def application(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/html')])
    return 'Hello there!'

application()函数接收两个参数

• environ: 一个字典对象, 包含所有HTTP请求信息
• start_response: 一个函数的应用，用来发送HTTP响应头信息

application()函数必须有返回值，返回响应body信息。

application()函数由WSGI服务器调用，参数亦在服务器中传入， 所有的HTTP解析、响应头和响应体信息的拼接都在服务器中完成，在框架中我们只需要完成应用程序的逻辑部分即可。

server端

web_server.py

import socket
import multiprocessing
import re
# import dynamic.mini_frame
import sys


class WSGIserver(object):
    def __init__(self, port, app, static_path):
        # 1. 创建套接字
        self.tcp_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.tcp_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        # 2. 绑定本地信息
        self.tcp_socket.bind(("", port))
        # 3. 套接字转为被动接听
        self.tcp_socket.listen(128)

        self.application = app
        self.static_path = static_path

    def serve_client(self, new_socket):
        """为这个客户端返回数据"""
        request = new_socket.recv(1024).decode("utf-8")
        request_lines = request.splitlines()
        print("")  # for test
        print(">" * 20)
        print(request_lines)

        file_name = ""
        ret = re.match(r"[^/]+(/[^ ]*)", request_lines[0])
        if ret:
            file_name = ret.group(1)
            if file_name == "/":
                file_name = "/index.html"

        # 不以.py结尾的就是静态页面， 直接返回数据给浏览器
        # 这里修改为判断'.html', 为了实现伪静态
        if not file_name.endswith('.html'):
            try:
                f = open(self.static_path + file_name, 'rb')
            except:
                response = "HTTP/1.1 404 NOT FOUND\r\n"
                response += 'Content-Type:text/html;charset=utf-8'
                response += "\r\n"
                response += "ooops 找不到页面了"
                new_socket.send(response.encode('utf-8'))
            else:
                html_content = f.read()
                f.close()

                response = "HTTP/1.1 200 OK\r\n"
                response += "\r\n"

                new_socket.send(response.encode('utf-8'))
                new_socket.send(html_content)
        # 其他都是以.py结尾的，动态资源请求给web框架处理
        # 现在这里为是以.html结尾
        else:
            env = dict()
            env['PATH_INFO'] = file_name  # 请求头
            # {'PATH_INFO': "/index.py}
            # body = dynamic.mini_frame.application(env, self.set_response_header)
            body = self.application(env, self.set_response_header)
            header = "HTTP/1.1 %s\r\n" % self.status
            # self.headers 框架返回的回应头
            for temp in self.headers:
                header += "%s:%s\r\n" % (temp[0], temp[1])
            header += "\r\n"
            response = header+body
            new_socket.send(response.encode('utf-8'))

    def set_response_header(self, status, headers):
        # 框架返回状态和回应头
        self.status = status
        self.headers = [("server", "mini_web v1.0")]
        self.headers += headers

    def run_forever(self):
        """用来完成整体控制"""
        # 4. 等待新客户端的链接
        while True:
            new_socket, client_addr = self.tcp_socket.accept()
            # 5. 为这个客户端服务
            p = multiprocessing.Process(target=self.serve_client, args=(new_socket,))
            p.start()

            new_socket.close()


def main():
    if len(sys.argv) == 3:
        try:
            port = int(sys.argv[1])  # 7890
            frame_app_name = sys.argv[2]  # mini_frame:application
        except Exception as err:
            print("端口输入错误.")
    else:
        print("请按照以下方式运行:")
        print("python3 xxxx.py 7890 mini_frame:application")
        return

    # mini_frame: application
    ret = re.match(r"([^:]+):(.*)", frame_app_name)
    if ret:
        frame_name = ret.group(1)
        app_name = ret.group(2)
    else:
        print("请按照以下方式运行:")
        print("python3 xxxx.py 7890 mini_frame:application")
        return

    with open("./web_server.conf") as f:
        conf_info = eval(f.read())
    # 此时config_info是一个字典

    sys.path.append(conf_info['dynamic_path'])  # 需要将web_server.py所在的文件夹添加到查询路径中

    # import frame_name  不能这样import,因为import不会将frame_name当作变量名,而是在文件夹中找frame_name.py
    frame = __import__(frame_name)  # 返回值标记着导入的这个模板
    app = getattr(frame, app_name)  # app指向了mini_frame中的application

    server = WSGIserver(port, app, conf_info['static_path'])
    server.run_forever()

if __name__ == '__main__':
    main()

框架端

import re
from pymysql import connect
import urllib.parse

# 创建一个空字典,用来存储路由
URL_ROUTE = {}


# 定义一个装饰器函数
def route(url):
    def wrapper_func(func):
        URL_ROUTE[url] = func

        def call_func(*args, **kwargs):
            return func(*args, **kwargs)

        return call_func

    return wrapper_func


@route(r'/add/(\d+).html')
def add_choose(file_name, url):
    """添加自选功能"""

    # 先通过正则判断,取出url里html前面的一部分,即股票代码
    ret = re.match(url, file_name)
    if ret:
        stock_code = ret.group(1)

    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    # 判断该股票是否已在关注列表
    sql = """select i.code from info as i inner join focus as f on i.id=f.info_id where i.code=%s;"""
    cursor.execute(sql, (stock_code,))
    if cursor.fetchone():
        cursor.close()
        db.close()
        return "该股票(%s)已在自选中了,请不要重复添加" % stock_code

    # 不在关注列表,则添加到关注列表中
    sql = """INSERT INTO focus (info_id) select id from info where code=%s;"""
    cursor.execute(sql, (stock_code,))
    db.commit()
    cursor.close()
    db.close()

    return "(%s)添加成功!" % stock_code


@route(r'/del/(\d+).html')
def del_choose(file_name, url):
    """删除自选"""
    ret = re.match(url, file_name)
    if ret:
        stock_code = ret.group(1)

    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    # 判断该股票是否不在关注列表
    sql = """select i.code from info as i inner join focus as f on i.id=f.info_id where i.code=%s;"""
    cursor.execute(sql, (stock_code,))
    if  not cursor.fetchone():
        cursor.close()
        db.close()
        return "在自选中没有该股票(%s),无法删除" % stock_code

    # 在关注列表,则从数据库focus中删除该记录
    sql = """delete from focus where info_id=(select id from info where code=%s);"""
    cursor.execute(sql, (stock_code,))
    db.commit()
    cursor.close()
    db.close()

    return "(%s)删除成功!" % stock_code


@route(r'/update/(\d+).html')
def show_update_page(file_name, url):
    """显示update页面"""
    ret = re.match(url, file_name)
    if ret:
        stock_code = ret.group(1)

    with open("./templates/update.html") as f:
        content = f.read()

    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    sql = '''select note_info from focus where info_id=(select id from info where code=%s) ;'''
    cursor.execute(sql, [stock_code])
    note_info = cursor.fetchone()

    cursor.close()
    db.close()

    # 使用正则替换content中的{%code%}
    content = re.sub(r"\{%code%\}", stock_code, content)
    # 使用正则替换content中的{%note_info%}  fetchone()取出来的是元祖,需要转换为str
    content = re.sub(r"\{%note_info%\}", str(note_info[0]), content)

    return content


@route(r'/update/(\d+)/(.*).html')
def update_note_info(file_name, url):
    ret = re.match(url, file_name)
    if ret:
        stock_code = ret.group(1)
        note_info = ret.group(2)

    # 浏览器会对中文进行url编码, 这里需要先解码
    note_info = urllib.parse.unquote(note_info)

    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    sql = '''UPDATE focus set note_info=%s where info_id=(select id from info where code=%s);'''
    cursor.execute(sql, [note_info, stock_code])
    db.commit()
    cursor.close()
    db.close()

    return "(%s)修改成功!" % stock_code


@route('/index.html')
def index(file_name, url):
    """返回index.html的内容"""
    with open("./templates/index.html") as f:
        content = f.read()

    # 这里替换为mysql中查询到的数据
    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    sql = "select * from info;"
    cursor.execute(sql)
    info_data = cursor.fetchall()

    cursor.close()
    db.close()

    html_template = '''
     <tr>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>%s</td>
        <td>
            <input type="button" value="添加" id="toAdd" name="toAdd" systemidvaule="%s">
    </tr>
    '''

    table_content = ""
    for line in info_data:
        table_content += html_template % (
            line[0], line[1], line[2], line[3], line[4], line[5], line[6], line[7], line[1])

    # 使用正则替换content中的{%content%}
    content = re.sub(r"\{%content%\}", table_content, content)
    return content


@route('/center.html')
def center(file_name, url):
    with open("./templates/center.html") as f:
        content = f.read()

    # my_stock_info = "BUG制造机"
    db = connect(host='localhost', port=3306, user='root', password='mysql', database='stock_db', charset='utf8')
    cursor = db.cursor()
    sql = '''
        select i.code,i.short,i.chg,i.turnover,i.price,i.highs,f.note_info
        from info as i inner join focus as f on f.info_id=i.id;
'''
    cursor.execute(sql)
    info_data = cursor.fetchall()

    cursor.close()
    db.close()

    html_template = '''
        <tr>
            <td>%s</td>
            <td>%s</td>
            <td>%s</td>
            <td>%s</td>
            <td>%s</td>
            <td>%s</td>
            <td>%s</td>
            <td>
              <a type="button" class="btn btn-default btn-xs" href="/update/%s.html"> <span class="glyphicon glyphicon-star" aria-hidden="true"></span> 修改 </a>
            </td>
            <td>
                <input type="button" value="删除" id="toDel" name="toDel" systemidvaule="%s">
            </td>
        </tr>
        '''

    table_content = ""
    for line in info_data:
        table_content += html_template % (
        line[0], line[1], line[2], line[3], line[4], line[5], line[6], line[0], line[0])

    # 使用正则替换content中的{%content%}
    content = re.sub(r"\{%content%\}", table_content, content)
    return content


# environ 是从服务器接受到的包含HTTP请求信息的dict对象， start_response指向服务器中的函数 发送HTTP报文信息
def application(environ, start_response):
    # start_response函数传入两个参数
    # 第一个是报文信息，第二个是报文头，列表[]
    start_response('200 OK', [('Content-Type', 'text/html;charset=utf-8')])
    # env = {'PATH_INFO': "/index.py"}
    file_name = environ['PATH_INFO']  # 取出"/index.py"

    try:
        # 把URL字典拆成两个元素,key是url,value是指向的方法
        for url, call_func in URL_ROUTE.items():
            # 将浏览器请求的url地址和字典里的url进行匹配, 如果成功调用方法
            ret = re.match(url, file_name)
            print(ret)
            if ret:
                # 将请求的地址和url当作参数传递给调用的函数
                return call_func(file_name, url)
        else:
            return "没有访问的页面 ---> %s" % file_name
            # return URL_ROUTE[file_name]()
    except Exception as err:
        return "----->>>%s" % str(err)