import redis.clients.jedis.Jedis;
import redis.clients.jedis.exceptions.JedisException;

public class RedisTransactionExample {

    private static final String REDIS_HOST = "localhost";
    private static final int REDIS_PORT = 6379;

    public static void main(String[] args) {
        Jedis jedis = new Jedis(REDIS_HOST, REDIS_PORT);

        try {
            // 開始事務(wù)
            jedis.watch("product:p001");
            String stockStr = jedis.get("product:p001");

            if (stockStr != null && Integer.parseInt(stockStr) > 0) {
                jedis.multi(); // 標記事務(wù)開始
                jedis.decr("product:p001"); // 減少庫存
                jedis.sadd("user:1001", "p001"); // 添加購買記錄
                List<Object> results = jedis.exec(); // 執(zhí)行事務(wù)

                if (results != null && results.size() == 2) {
                    System.out.println("Transaction executed successfully.");
                } else {
                    System.out.println("Transaction failed or was cancelled.");
                }
            } else {
                System.out.println("Not enough stock.");
            }

        } catch (NumberFormatException e) {
            System.err.println("Invalid stock value: " + stockStr);
        } catch (JedisException e) {
            System.err.println("Error while executing transaction: " + e.getMessage());
        } finally {
            if (jedis != null) {
                jedis.close();
            }
        }
    }
}