import os, json
from flask import Flask, render_template, flash, request, redirect, jsonify, session
from flask import escape, url_for, make_response, abort
from werkzeug.utils import secure_filename
from utils.db.MySQLUtil import MySQLUtil

UPLOAD_FOLDER = './'
ALLOWED_EXTENSIONS = {'txt', 'log', 'pdf', 'png', 'jpg', 'jpeg', 'gif'}
app = Flask(__name__)

app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024

app.secret_key = 'A0Zr98j/3yX R~XHH!jmN]LWX/,?RT'

@app.route('/index', methods=['GET', 'POST'])
def index():
    """请求方法和cookie"""
    method = request.method
    username = request.cookies.get('username')
    print(method, username)
    return render_template('index.html', name="name_welcome")

@app.route('/hello/')
@app.route('/hello/<name>')
def hello(name=None):
    """变量规则"""
    return render_template('hello.html', name=name)

def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

@app.route('/upload', methods=['GET', 'POST'])
def upload_file():
    """文件上传"""
    if request.method == 'POST':
        # check if the post request has the file part
        if 'file' not in request.files:
            flash('No file part')
            return redirect(request.url)
        file = request.files['file']
        # if user does not select file, browser also
        # submit an empty part without filename
        if file.filename == '':
            flash('No selected file')
            return render_template('upload.html')
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            flash('upload file success')
            return url_for('upload_file', filename=filename)
    return render_template('upload.html')

@app.route('/match/<str>')
def match_url(str):
    """url构建"""
    print('{}\'s profile'.format(escape(str)))
    return render_template(str+".html")

@app.route('/<str>')
def url_forward(str):
    """url构建"""
    return render_template(str)

@app.route('/set_cookie')
def set_cookie():
    """存储cookie"""
    response = make_response("set cookie success")
    response.set_cookie('username', 'the username')
    flash(str(response))
    return redirect(url_for('index'))

@app.route('/get_cookie')
def get_cookie():
    """读取cookie"""
    cookie = request.cookies.get('username')
    flash(cookie)
    return redirect(url_for('index'))

@app.route("/del_cookie")
def del_cookie():
    """删除cookie（删除只是让cookie过期）"""
    response = make_response("delete cookie success")
    response.delete_cookie("username")
    flash(str(response))
    return redirect(url_for('index'))

@app.route('/')
def my_redirect():
    return redirect(url_for('login'))

@app.errorhandler(404)
def page_not_found(error):
    """404状态返回网页"""
    return render_template('404.html'), 404

@app.route('/login', methods = ['GET', 'POST'])
def login():
    """消息闪现"""
    error = None
    if request.method == 'POST':
        if request.form['username'] != 'admin': ## or request.form['password'] != 'admin':
           error = "Invalid username or password. Please try again!"
        else:
           flash('You were successfully logged in')
           return redirect(url_for('index'))
    return render_template('login.html', error=error)

@app.route('/logout')
def logout():
    """删除session中的username"""
    session.pop('username', None)
    return redirect(url_for('login'))

@app.route('/kv-result', methods=['POST', 'GET'])
def result():
    """将表单数据返回给模板"""
    if request.method == 'POST':
      result = request.form
      print(result)
      return render_template("kv-result.html", result=result)

@app.route('/mysql_db', methods=['POST', 'GET'])
def mysql_db():
    """查询MySQL全部数据库名称"""
    if request.method == 'POST':
      form = request.form
      print(type(form), form)
      ip = form['ip']
      port = form['port']
      username = form['username']
      password = form['password']
      print(ip, port, username, password)
      mysqlUtil = MySQLUtil(ip, port, username, password)
      dbs = mysqlUtil.list_databases()
      print(dbs)
      return render_template("result.html", result=dbs)

if __name__ == '__main__':
    print(1111)
    app.run(host='0.0.0.0', port='5000', debug=True, threaded=True)
    app.logger.debug('A value for debugging')
    app.logger.warning('A warning occurred (%d apples)', 42)
    app.logger.error('An error occurred')
    print(2222)

flash.py

#-*- encoding: utf-8 -*-

from flask import Flask, flash, redirect, render_template, request, url_for
app = Flask(__name__)

app.secret_key = 'random string'

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/login', methods = ['GET', 'POST'])
def login():
    error = None
    if request.method == 'POST':
        if request.form['username'] != 'admin' or \
            request.form['password'] != 'admin':
            error = 'Invalid username or password. Please try again!'
        else:
            flash('You were successfully logged in')
            return redirect(url_for('index'))
    return render_template('login.html', error=error)

if __name__ == "__main__":
    app.run(debug=True)