WEB框架--Tornado
Tornado是FriendFeed使用的可扩展的非阻塞式web服务器及其相关工具的开源版本。这个Web框架看起来有些像web.py 或者Google的webapp，不过为了能有效利用非阻塞式服务器环境，这个Web框架还包含了一些相关的有用工具 和优化。
Tornado和现在的主流Web服务器框架（包括大多数Python的框架）有着明显的区别：它是非阻塞式服务器，而且速度相当快。得利于其 非阻塞的方式和对epoll的运用，Tornado 每秒可以处理数以千计的连接，因此Tornado是实时Web服务的一个 理想框架。我们开发这个Web服务器的主要目的就是为了处理FriendFeed的实时功能 ——在FriendFeed的应用里每一个活动用户都会保持着一个服务器连接。（关于如何扩容 服务器，以处理数以千计的客户端的连接的问题，请参阅The C10K problem）。（百度百科）
下载安装：
pip3 install tornado
一 基础使用
import tornado.ioloop
from tornado.web import RequestHandler
class IndexHandler(RequestHandler):
def get(self):
self.write("Hello, world")
application = tornado.web.Application([
(r"/index", IndexHandler),
])
if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
执行过程：
- 第一步：执行脚本，监听 8888 端口
- 第二步：浏览器客户端访问 /index --> http://127.0.0.1:8888/index
- 第三步：服务器接受请求，并交由对应的类处理该请求
- 第四步：类接受到请求之后，根据请求方式（post / get / delete ...）的不同调用并执行相应的方法
- 第五步：方法返回值的字符串内容发送浏览器
二 路由系统
路由系统其实就是 url 和类的对应关系，Tornado不同于其他框架，其他很多框架均是 url 对应函数，Tornado中每个url对应的是一个类，如上示例。
Tornado中原生支持二级域名的路由，如：
三 模板引擎
Tornao中的模板语言和Django类似，模板引擎将模板文件载入内存，然后将数据嵌入其中，最终获取到一个完整的字符串，再将字符串返回给请求者。
Tornado 的模板支持“控制语句”和“表达语句”
- 控制语句是使用
{%和%}包起来的 例如{% if len(items) > 2 %} 表达语句是使用{{和}}包起来的，例如{{ items[0] }}。
控制语句和对应的 Python 语句的格式基本完全相同。支持 if、for、while 和 try，这些语句逻辑结束的位置需要用 {% end %} 做标记。
另外，还通过 extends 和 block 语句实现了模板继承及通过include导入
注：在使用模板前需要在setting中设置模板路径："template_path" : "xxxx"
3.1 基础使用
import tornado.ioloop from tornado.web import RequestHandler class IndexHandler(RequestHandler): def get(self): self.render("index.html", book_info=['西游记','红楼梦','水浒传','三国演义']) settings = { 'template_path':'templates', # 设置模板文件路径 'static_path':'static', # 设置静态文件路径 # 'static_url_prefix':'/static/', } application = tornado.web.Application([ (r"/index.html", IndexHandler), ],**settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>Titel</title>
<link rel="stylesheet" href="/static/comment.css">
<!--<link rel="stylesheet" href="{{static_url('comment.css')}}" >-->
</head>
<body>
<h3 class="c1">书籍清单</h3>
<div>
<ul>
{% for item in book_info %}
<li>{{item}}</li>
{% end %}
</ul>
</div>
</body>
</html>
在模板中默认提供了一些函数、字段、类以供模板使用：
escape: tornado.escape.xhtml_escape 的別名
xhtml_escape: tornado.escape.xhtml_escape 的別名
url_escape: tornado.escape.url_escape 的別名
json_encode: tornado.escape.json_encode 的別名
squeeze: tornado.escape.squeeze 的別名
linkify: tornado.escape.linkify 的別名
datetime: Python 的 datetime 模组
handler: 当前的 RequestHandler 对象
request: handler.request 的別名
current_user: handler.current_user 的別名
locale: handler.locale 的別名
_: handler.locale.translate 的別名
static_url: for handler.static_url 的別名
xsrf_form_html: handler.xsrf_form_html 的別名
3.2 模板
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> {% block css %}{% end %} </head> <body> <div style="height: 48px;background-color: olivedrab"></div> {% block content %}{% end %} {% block javascript %}{% end %} </body> </html>
{% extends "layout.html" %}
{% block css %}
<link rel="stylesheet" href="/static/comment.css">
<!--<link rel="stylesheet" href="{{static_url('comment.css')}}" >-->
{% end %}
{% block content %}
<h3 class="c1">书籍清单</h3>
<div>
<ul>
{% for item in book_info %}
<li>{{item}}</li>
{% end %}
</ul>
</div>
{% end %}
{% block javascript %}{% end %}
3.3 导入
<div> <ul> <li>网络是怎样连接的</li> <li>计算机是怎样跑起来的</li> <li>程序是怎样跑起来的</li> </ul> </div>
{% extends "layout.html" %}
{% block css %}
<link rel="stylesheet" href="/static/comment.css">
<!--<link rel="stylesheet" href="{{static_url('comment.css')}}" >-->
{% end %}
{% block content %}
<h3 class="c1">书籍清单</h3>
<div>
<ul>
{% for item in book_info %}
<li>{{item}}</li>
{% end %}
</ul>
</div>
<h4 class="c2">补充书籍</h4>
{% include 'other.html' %}
{% end %}
{% block javascript %}{% end %}
3.4 自定义UIMethod以UIModule
a. 定义
def func(self): print(self) # <__main__.IndexHandler object at 0x0000020A1FCEC518> return 'func返回值'
from tornado.web import UIModule class Foo(UIModule): def render(self, *args, **kwargs): print(self, args, kwargs) # <uimodules.Foo object at 0x0000020A1FCFEAC8> (123,) {} return 'UIModule返回值' def css_files(self): """引入css文件""" return ["/xxx/common.css",] def embedded_css(self): """引入css代码""" tpm = """ .c2{ color:green } """ return tpm def javascript_files(self): """引入js文件""" return ["/xxx/common.js",] def embedded_javascript(self): """引入js代码""" tpm =""" v = 123; console.log(v); """ return tpm
b. 注册
import tornado.ioloop from tornado.web import RequestHandler import uimodules as md import uimethods as mt class IndexHandler(RequestHandler): def get(self): self.render("index.html", book_info=['西游记','红楼梦','水浒传','三国演义']) settings = { 'template_path':'templates', # 设置模板文件路径 'static_path':'static', # 设置静态文件路径 # 'static_url_prefix':'/static/', 'ui_methods': mt, 'ui_modules': md, } application = tornado.web.Application([ (r"/index.html", IndexHandler), ],**settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
c.使用
{% extends "layout.html" %}
{% block css %}
<link rel="stylesheet" href="/static/comment.css">
<!--<link rel="stylesheet" href="{{static_url('comment.css')}}" >-->
{% end %}
{% block content %}
{% module Foo(123) %}
{{ func() }}
{% end %}
{% block javascript %}{% end %}
四 静态文件
对于静态文件，可以配置静态文件的目录和前段使用时的前缀，并且Tornaodo还支持静态文件缓存。
settings = {
'template_path': 'template',
'static_path': 'static',
'static_url_prefix': '/static/',
}
<link rel="stylesheet" href="{{static_url("comment.css")}}"/>
def get_content_version(cls, abspath): """Returns a version string for the resource at the given path. This class method may be overridden by subclasses. The default implementation is a hash of the file's contents. .. versionadded:: 3.1 """ data = cls.get_content(abspath) hasher = hashlib.md5() if isinstance(data, bytes): hasher.update(data) else: for chunk in data: hasher.update(chunk) return hasher.hexdigest()
五 Cookie
Tornado中可以对Cookie进行操作，并且还可以对Cookie进行签名以防止伪造
5.1 基本操作
class CookieHandler(RequestHandler): def get(self): if not self.get_cookie("mycookie"): self.set_cookie("mycookie", "myvalue") self.write("Your cookie was not set yet!") else: self.write("Your cookie was set!")
5.2 加密Cookie（签名）
Cookie 很容易被恶意的客户端伪造。假如你想在 Cookie 中保存当前登陆用户的 id 之类的信息，你需要对 Cookie 作签名以防止伪造。Tornado 通过 set_secure_cookie 和 get_secure_cookie 方法直接支持了这种功能。 要使用这些方法，你需要在创建应用时提供一个密钥，名字为 cookie_secret。 你可以把它作为一个关键词参数传入应用的设置中：
class CookieHandler(RequestHandler): def get(self): if not self.get_secure_cookie("mycookie"): self.set_secure_cookie("mycookie", "myvalue") self.write("Your cookie was not set yet!") else: self.write("Your cookie was set!") application = tornado.web.Application([ (r"/index.html", IndexHandler), (r"/cookie.html", CookieHandler), ],cookie_secret='abcdefg111',)
def _create_signature_v1(secret, *parts): hash = hmac.new(utf8(secret), digestmod=hashlib.sha1) for part in parts: hash.update(utf8(part)) return utf8(hash.hexdigest()) # 加密 def _create_signature_v2(secret, s): hash = hmac.new(utf8(secret), digestmod=hashlib.sha256) hash.update(utf8(s)) return utf8(hash.hexdigest()) def create_signed_value(secret, name, value, version=None, clock=None, key_version=None): if version is None: version = DEFAULT_SIGNED_VALUE_VERSION if clock is None: clock = time.time timestamp = utf8(str(int(clock()))) value = base64.b64encode(utf8(value)) if version == 1: signature = _create_signature_v1(secret, name, value, timestamp) value = b"|".join([value, timestamp, signature]) return value elif version == 2: # The v2 format consists of a version number and a series of # length-prefixed fields "%d:%s", the last of which is a # signature, all separated by pipes. All numbers are in # decimal format with no leading zeros. The signature is an # HMAC-SHA256 of the whole string up to that point, including # the final pipe. # # The fields are: # - format version (i.e. 2; no length prefix) # - key version (integer, default is 0) # - timestamp (integer seconds since epoch) # - name (not encoded; assumed to be ~alphanumeric) # - value (base64-encoded) # - signature (hex-encoded; no length prefix) def format_field(s): return utf8("%d:" % len(s)) + utf8(s) to_sign = b"|".join([ b"2", format_field(str(key_version or 0)), format_field(timestamp), format_field(name), format_field(value), b'']) if isinstance(secret, dict): assert key_version is not None, 'Key version must be set when sign key dict is used' assert version >= 2, 'Version must be at least 2 for key version support' secret = secret[key_version] signature = _create_signature_v2(secret, to_sign) return to_sign + signature else: raise ValueError("Unsupported version %d" % version) # 解密 def _decode_signed_value_v1(secret, name, value, max_age_days, clock): parts = utf8(value).split(b"|") if len(parts) != 3: return None signature = _create_signature_v1(secret, name, parts[0], parts[1]) if not _time_independent_equals(parts[2], signature): gen_log.warning("Invalid cookie signature %r", value) return None timestamp = int(parts[1]) if timestamp < clock() - max_age_days * 86400: gen_log.warning("Expired cookie %r", value) return None if timestamp > clock() + 31 * 86400: # _cookie_signature does not hash a delimiter between the # parts of the cookie, so an attacker could transfer trailing # digits from the payload to the timestamp without altering the # signature. For backwards compatibility, sanity-check timestamp # here instead of modifying _cookie_signature. gen_log.warning("Cookie timestamp in future; possible tampering %r", value) return None if parts[1].startswith(b"0"): gen_log.warning("Tampered cookie %r", value) return None try: return base64.b64decode(parts[0]) except Exception: return None def _decode_fields_v2(value): def _consume_field(s): length, _, rest = s.partition(b':') n = int(length) field_value = rest[:n] # In python 3, indexing bytes returns small integers; we must # use a slice to get a byte string as in python 2. if rest[n:n + 1] != b'|': raise ValueError("malformed v2 signed value field") rest = rest[n + 1:] return field_value, rest rest = value[2:] # remove version number key_version, rest = _consume_field(rest) timestamp, rest = _consume_field(rest) name_field, rest = _consume_field(rest) value_field, passed_sig = _consume_field(rest) return int(key_version), timestamp, name_field, value_field, passed_sig def _decode_signed_value_v2(secret, name, value, max_age_days, clock): try: key_version, timestamp, name_field, value_field, passed_sig = _decode_fields_v2(value) except ValueError: return None signed_string = value[:-len(passed_sig)] if isinstance(secret, dict): try: secret = secret[key_version] except KeyError: return None expected_sig = _create_signature_v2(secret, signed_string) if not _time_independent_equals(passed_sig, expected_sig): return None if name_field != utf8(name): return None timestamp = int(timestamp) if timestamp < clock() - max_age_days * 86400: # The signature has expired. return None try: return base64.b64decode(value_field) except Exception: return None def get_signature_key_version(value): value = utf8(value) version = _get_version(value) if version < 2: return None try: key_version, _, _, _, _ = _decode_fields_v2(value) except ValueError: return None return key_version
签名Cookie的本质是：
写Cookie过程：
- 将值进行base64加密
- 对除值以外的内容进行签名，哈希算法（无法逆向解析）
- 拼接签名 + 加密值
读Cookie过程：
- 读取 签名 + 加密值
- 对签名进行验证
- base64解密，获取值内容
import tornado.ioloop from tornado.web import RequestHandler import uimodules as md import uimethods as mt class IndexHandler(RequestHandler): """主页""" def get(self): login_user = self.get_cookie("login_user") if login_user: self.render("index.html", book_info=['西游记','红楼梦','水浒传','三国演义']) else: self.redirect('/login.html') class LoginHandler(RequestHandler): """登录""" def get(self, *args, **kwargs): self.render('login.html',**{'msg':''}) # 不返回会报错 def post(self, *args, **kwargs): user = self.get_argument('user') # 同时从get/post中获取数据 pwd = self.get_argument('pwd') if user == 'root' and pwd == '123': import time v = time.time()+60 self.set_cookie('login_user',user,expires=v) # 设置cookie,expires代表保持时间 self.redirect('/index.html') else: self.render('login.html',**{'msg':'用户名或密码错误'}) settings = { 'template_path':'templates', # 设置模板文件路径 'static_path':'static', # 设置静态文件路径 'static_url_prefix':'/static/', 'ui_methods': mt, 'ui_modules': md, } application = tornado.web.Application([ (r"/login.html", LoginHandler), (r"/index.html", IndexHandler), ],**settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
import tornado.ioloop from tornado.web import RequestHandler import uimodules as md import uimethods as mt class IndexHandler(RequestHandler): """主页""" def get(self): login_user = self.get_secure_cookie("login_user") if login_user: self.render("index.html", book_info=['西游记','红楼梦','水浒传','三国演义']) else: self.redirect('/login.html') class LoginHandler(RequestHandler): """登录""" def get(self, *args, **kwargs): self.render('login.html',**{'msg':''}) # 不返回msg会报错 def post(self, *args, **kwargs): user = self.get_argument('user') # 同时从get/post中获取数据 pwd = self.get_argument('pwd') if user == 'root' and pwd == '123': import time v = time.time()+60 # self.set_cookie('login_user',user,expires=v) # 设置cookie,expires代表保持时间 self.set_secure_cookie('login_user', user, expires=v) # 设置加密cookie self.redirect('/index.html') else: self.render('login.html',**{'msg':'用户名或密码错误'}) settings = { 'template_path':'templates', # 设置模板文件路径 'static_path':'static', # 设置静态文件路径 'static_url_prefix':'/static/', 'cookie_secret':'abcd111', 'ui_methods': mt, 'ui_modules': md, } application = tornado.web.Application([ (r"/login.html", LoginHandler), (r"/index.html", IndexHandler), ],**settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
import tornado.ioloop from tornado.web import RequestHandler import uimodules as md import uimethods as mt from tornado.web import authenticated class XRequestHandler(RequestHandler): def get_current_user(self): return self.get_secure_cookie('login_user') class IndexHandler(XRequestHandler): """主页""" @authenticated def get(self): self.render("index.html", book_info=['西游记','红楼梦','水浒传','三国演义']) class LoginHandler(RequestHandler): """登录""" def get(self, *args, **kwargs): self.render('login.html',**{'msg':''}) # 不返回msg会报错 def post(self, *args, **kwargs): user = self.get_argument('user') # 同时从get/post中获取数据 pwd = self.get_argument('pwd') if user == 'root' and pwd == '123': import time v = time.time()+60 # self.set_cookie('login_user',user,expires=v) # 设置cookie,expires代表保持时间 self.set_secure_cookie('login_user', user, expires=v) # 设置加密cookie self.redirect('/index.html') else: self.render('login.html',**{'msg':'用户名或密码错误'}) settings = { 'template_path':'templates', # 设置模板文件路径 'static_path':'static', # 设置静态文件路径 'static_url_prefix':'/static/', 'cookie_secret':'abcd111', 'ui_methods': mt, 'ui_modules': md, 'login_url':'/login.html', # 验证不通过跳转到该页面 } application = tornado.web.Application([ (r"/login.html", LoginHandler), (r"/index.html", IndexHandler), ],**settings) if __name__ == "__main__": application.listen(8888) tornado.ioloop.IOLoop.instance().start()
5.3 JavaScript操作Cookie
由于Cookie保存在浏览器端，所以在浏览器端也可以使用JavaScript来操作Cookie
# 设置cookie，指定秒数过期 function setCookie(name,value,expires){ var temp = []; var current_date = new Date(); current_date.setSeconds(current_date.getSeconds() + 5); document.cookie = name + "= "+ value +";expires=" + current_date.toUTCString(); }
对于参数：
- domain 指定域名下的cookie
- path 域名下指定url中的cookie
- secure https使用
六 CSRF
Tornado中的夸张请求伪造和Django中的相似
settings = {
'xsrf_cookies':True,
}
application = tornado.web.Application([
(r"/login.html", LoginHandler),
(r"/index.html", IndexHandler),
],**settings)
<form method="post"> {{ xsrf_form_html() }} <!-- 页面直接显示 --> {% raw xsrf_form_html() %} <p>用户名：<input type="text" name="user"></p> <p>密码：<input type="password" name="pwd"></p> <input type="submit" value="提交">{{ msg }} </form>
function getCookie(name) { var r = document.cookie.match("\\b" + name + "=([^;]*)\\b"); return r ? r[1] : undefined; } jQuery.postJSON = function(url, args, callback) { args._xsrf = getCookie("_xsrf"); $.ajax({url: url, data: $.param(args), dataType: "text", type: "POST", success: function(response) { callback(eval("(" + response + ")")); }}); };
七上传文件
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