Python实现简单HTTP服务器

Posted 2020-11-09 YangPython

实现简单web框架

一.框架(MyWeb.py)

# coding:utf-8

import time

# 设置静态文件根目录
HTML_ROOT_DIR = "./html"


class Application(object):
    def __init__(self, urls):
        # 设置路由信息
        self.urls = urls

    def __call__(self, env, start_response):
        path = env.get("PATH_INFO", "/")
        if path.startswith("/static"):
            # 要访问静态文件
            file_name = path[7:]
            # 打开文件，读取内容
            try:
                file = open(HTML_ROOT_DIR + file_name, "rb")
            except IOError:
                # 代表未找到路由信息，404错误
                status = "404 Not Found"
                headers = []
                start_response(status, headers)
                return "not found"
            else:
                file_data = file.read()
                file.close()

                status = "200 OK"
                headers = []
                start_response(status, headers)
                return file_data.decode("utf-8")

        for url, handler in self.urls:
            if path == url:
                return handler(env, start_response)

        # 代表未找到路由信息，404错误
        status = "404 Not Found"
        headers = []
        start_response(status, headers)
        return "not found"


def show_ctime(env, start_response):
    status = "200 OK"
    headers = [("Content-Type", "text/plain")]
    start_response(status, headers)
    return time.ctime()


def echo_test(env, start_response):
    status = "200 OK"
    headers = [("Content-Type", "text/plain")]
    start_response(status, headers)
    return \'Python Test\'


urls = [
            ("/", show_ctime),
            ("/ctime", show_ctime),
            ("/echo", echo_test),
        ]
app = Application(urls)

二.服务器(MyServer.py)

# coding:utf-8

import socket
import re
import sys
from multiprocessing import Process


class HTTPServer(object):
    def __init__(self, application):
        """
        application：指的是框架的app
        """
        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.app = application

    def start(self):
        self.server_socket.listen(128)
        while True:
            client_socket, client_address = self.server_socket.accept()
            print("[%s, %s]用户连接上了" % client_address)
            handle_client_process = Process(target=self.handle_client, args=(client_socket,))
            handle_client_process.start()
            client_socket.close()

    def start_response(self, status, headers):
        response_headers = "HTTP/1.1 " + status + "\\r\\n"
        for header in headers:
            response_headers += "%s: %s\\r\\n" % header
        self.response_headers = response_headers

    def handle_client(self, client_socket):
        """
        处理客户端请求
        """
        # 获取客户端请求数据
        request_data = client_socket.recv(1024)
        print("request data:", request_data)
        request_lines = request_data.splitlines()
        for line in request_lines:
            print(line)

        # 解析请求报文
        request_start_line = request_lines[0]
        # 提取用户请求的文件名及请求方法
        file_name = re.match(r"\\w+ +(/[^ ]*) ", request_start_line.decode("utf-8")).group(1)
        method = re.match(r"(\\w+) +/[^ ]* ", request_start_line.decode("utf-8")).group(1)

        env = {
            "PATH_INFO": file_name,
            "METHOD": method
        }
        response_body = self.app(env, self.start_response)

        response = self.response_headers + "\\r\\n" + response_body
        # 向客户端返回响应数据
        client_socket.send(bytes(response, "utf-8"))
        # 关闭客户端连接
        client_socket.close()

    def bind(self, port):
        self.server_socket.bind(("", port))


def main():
    if len(sys.argv) < 2:
        sys.exit("python MyWebServer.py Module:app")
    module_name, app_name = sys.argv[1].split(":")
    # module_name = "MyWebFrameWork"
    # app_name = "app"
    m = __import__(module_name)
    app = getattr(m, app_name)
    http_server = HTTPServer(app)
    http_server.bind(8000)
    http_server.start()


if __name__ == "__main__":
    main()

终端输入：python MyServer.py MyWeb：app

浏览器输入：http://127.0.0.1:8000/static/index.html，显示静态文件内容

浏览器输入：http://127.0.0.1:8000/，显示相应的动态内容：