短域名系统源码

import sqlite3
import hashlib

# 创建数据库和表
conn = sqlite3.connect('short_url.db')
c = conn.cursor()
c.execute('''CREATE TABLE IF NOT EXISTS url_mapping (short_url TEXT PRIMARY KEY, long_url TEXT)''')
conn.commit()

def generate_short_url(long_url):
    # 使用MD5哈希生成短网址
    hash_object = hashlib.md5(long_url.encode())
    short_url = hash_object.hexdigest()[:8]
    
    # 检查短网址是否已存在
    c.execute("SELECT * FROM url_mapping WHERE short_url=?", (short_url,))
    if c.fetchone():
        return generate_short_url(long_url)  # 如果存在冲突，重新生成
    
    # 存储映射关系
    c.execute("INSERT INTO url_mapping (short_url, long_url) VALUES (?, ?)", (short_url, long_url))
    conn.commit()
    
    return short_url

def redirect_to_long_url(short_url):
    c.execute("SELECT long_url FROM url_mapping WHERE short_url=?", (short_url,))
    result = c.fetchone()
    if result:
        return result[0]
    else:
        return "Short URL not found"

# 示例使用
long_url = "https://www.example.com/very/long/url/that/needs/to/be/shortened"
short_url = generate_short_url(long_url)
print(f"Short URL: {short_url}")

redirected_url = redirect_to_long_url(short_url)
print(f"Redirected to: {redirected_url}")

conn.close()