在Java中使用Redis实现缓存优化的操作步骤

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>3.6.0</version>
</dependency>

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class RedisConfig {
    private JedisPool jedisPool;

    // 初始化连接池
    public RedisConfig() {
        JedisPoolConfig poolConfig = new JedisPoolConfig();
        poolConfig.setMaxTotal(128);  // 最大连接数
        poolConfig.setMaxIdle(64);    // 最大空闲连接数
        poolConfig.setMinIdle(16);    // 最小空闲连接数
        poolConfig.setTestOnBorrow(true);  // 检查连接是否可用

        // 创建连接池，指定 Redis 服务地址和端口
        jedisPool = new JedisPool(poolConfig, "localhost", 6379);
    }

    // 获取 Jedis 实例
    public Jedis getJedis() {
        return jedisPool.getResource();
    }

    // 关闭连接池
    public void close() {
        if (jedisPool != null) {
            jedisPool.close();
        }
    }
}

public class CacheService {
    private RedisConfig redisConfig;

    public CacheService() {
        redisConfig = new RedisConfig();
    }

    // 向 Redis 中写入缓存
    public void setCache(String key, String value) {
        try (Jedis jedis = redisConfig.getJedis()) {
            jedis.set(key, value);
        }
    }

    // 关闭连接
    public void close() {
        redisConfig.close();
    }
}

public class CacheService {
    private RedisConfig redisConfig;

    public CacheService() {
        redisConfig = new RedisConfig();
    }

    // 从 Redis 中获取缓存
    public String getCache(String key) {
        try (Jedis jedis = redisConfig.getJedis()) {
            return jedis.get(key);
        }
    }

    public void close() {
        redisConfig.close();
    }
}

public class UserService {
    private CacheService cacheService;
    private DatabaseService databaseService;

    public UserService() {
        cacheService = new CacheService();
        databaseService = new DatabaseService();
    }

    public String getUserInfo(int userId) {
        String cacheKey = "user_" + userId;
        
        // 先检查缓存
        String userInfo = cacheService.getCache(cacheKey);
        
        if (userInfo == null) {
            // 如果缓存不存在，从数据库获取
            userInfo = databaseService.getUserInfoFromDb(userId);
            // 将结果存入缓存
            cacheService.setCache(cacheKey, userInfo);
        }
        
        return userInfo;
    }

    public void close() {
        cacheService.close();
    }
}

public class DatabaseService {
    public String getUserInfoFromDb(int userId) {
        // 假设这是一个数据库查询的操作
        // 这里我们使用一个简单的字符串模拟从数据库中查询用户信息
        return "User Info for ID " + userId;
    }
}

public void setCacheWithExpire(String key, String value, int seconds) {
    try (Jedis jedis = redisConfig.getJedis()) {
        jedis.setex(key, seconds, value);  // 设置缓存并指定过期时间
    }
}