短地址 php

<?php
// 数据库连接
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "short_url_db";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 生成短地址
function generateShortUrl($longUrl) {
    global $conn;
    $hash = hash('md5', $longUrl);
    $shortUrl = substr($hash, 0, 8); // 取前8位作为短地址

    // 检查短地址是否已存在
    $sql = "SELECT * FROM url_mapping WHERE short_url = '$shortUrl'";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        // 如果已存在，重新生成
        return generateShortUrl($longUrl);
    } else {
        // 存储映射关系
        $sql = "INSERT INTO url_mapping (long_url, short_url) VALUES ('$longUrl', '$shortUrl')";
        $conn->query($sql);
        return $shortUrl;
    }
}

// 重定向短地址
if (isset($_GET['url'])) {
    $shortUrl = $_GET['url'];
    $sql = "SELECT long_url FROM url_mapping WHERE short_url = '$shortUrl'";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
        header("Location: " . $row["long_url"]);
        exit();
    } else {
        echo "短地址无效";
    }
} else {
    // 示例：生成短地址
    $longUrl = "https://www.example.com/very/long/url/that/needs/to/be/shortened";
    $shortUrl = generateShortUrl($longUrl);
    echo "长网址: $longUrl<br>";
    echo "短地址: http://yourdomain.com/?url=$shortUrl";
}

$conn->close();
?>