Python實現搭建-簡單伺服器教程

Python動態伺服器網頁（需要使用WSGI介面），基本實現步驟如下：
1.等待客戶端的鏈接，伺服器會收到一個http協議的請求數據報
2.利用正則表達式對這個請求數據報進行解析（請求方式、提取出文件的環境）
3.提取出文件的環境之後，利用截斷取片的方法將文件名轉化為模塊名稱
4.使用m = __import__(),就可以得到返回值為m的模塊
5.創建一個env字典：其中包含的是請求方式及文件環境等各種的鍵值對
6.創建一個新的動態腳本，其中定義了application這個函數，必須包含env和start_response的參數（也是伺服器里的調用方法）
7.在這個動態腳本中定義狀態碼status和響應頭headers（註意是字典形式，如Content-Type）
8.然後再調用start_response(status,headers)，但是要註意，這個函數在伺服器被定義
9.在動態腳本中編寫動態執行程式
10.m.appliction的返回值就是回應數據包的body，它的數據頭在start_response被整合
11.將數據頭與數據body拼接起來，然後發送給客戶端，就可顯示動態網頁

MyWebServer

import socket
import re
import sys
 
from multiprocessing import Process
from MyWebFramework import Application
 
# 設置靜態文件根目錄
HTML_ROOT_DIR = "./html"
WSGI_PYTHON_DIR = "./wsgipython"
 
class HTTPServer(object):
    """"""
    def __init__(self, application):
        """構造函數， 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]用戶連接上了" % (client_address[0],client_address[1]))
            print("[%s, %s]用戶連接上了" % 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):
        """
         status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    star
        """
        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):
        """處理客戶端請求"""
        # 獲取客戶端請求數據
        request_data = client_socket.recv(1024)
        print("request data:", request_data)
        request_lines = request_data.splitlines()
        for line in request_lines:
            print(line)
 
        # 解析請求報文
        # 'GET / HTTP/1.1'
        request_start_line = request_lines[0]
        # 提取用戶請求的文件名
        print("*" * 10)
        print(request_start_line.decode("utf-8"))
        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
 
        # 向客戶端返迴響應數據
        client_socket.send(bytes(response, "utf-8"))
        # 關閉客戶端連接
        client_socket.close()
 
    def bind(self, port):
        self.server_socket.bind(("", port))
 
def main():
    sys.path.insert(1, WSGI_PYTHON_DIR)
    if len(sys.argv) < 2:
        sys.exit("python MyWebServer.py Module:app")
    # python MyWebServer.py  MyWebFrameWork: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.set_port
    http_server.bind(8000)
    http_server.start()
 
if __name__ == "__main__":
    main()

MyWebFrameWork

import time
# from MyWebServer import HTTPServer
 
# 設置靜態文件根目錄
HTML_ROOT_DIR = "./html"
 
class Application(object):
    """框架的核心部分，也就是框架的主題程式，框架是通用的"""
    def __init__(self, urls):
        # 設置路由信息
        self.urls = urls
 
    def __call__(self, env, start_response):
        path = env.get("PATH_INFO", "/")
        # /static/index.html
        if path.startswith("/static"):
            # 要訪問靜態文件
            file_name = path[7:]
            # 打開文件，讀取內容
            try:
                file = open(HTML_ROOT_DIR + file_name, "rb")
            except IOError:
                # 代表未找到路由信息，404錯誤
                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:
            #("/ctime", show_ctime)
            if path == url:
                return handler(env, start_response)
 
        # 代表未找到路由信息，404錯誤
        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 say_hello(env, start_response):
    status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    start_response(status, headers)
    return "hello itcast"
 
def say_haha(env, start_response):
    status = "200 OK"
    headers = [
        ("Content-Type", "text/plain")
    ]
    start_response(status, headers)
    return "hello haha"
 
urls = [
            ("/", show_ctime),
            ("/ctime", show_ctime),
            ("/sayhello", say_hello),
            ("/sayhaha", say_haha),
        ]
app = Application(urls)
# if __name__ == "__main__":
#     urls = [
#             ("/", show_ctime),
#             ("/ctime", show_ctime),
#             ("/sayhello", say_hello),
#             ("/sayhaha", say_haha),
#         ]
#     app = Application(urls)
#     http_server = HTTPServer(app)
#     http_server.bind(8000)
#     http_server.start()