项目组同事提出一个问题，使用Spring RestTemplate不能在“不存在时设值”的同时，设置超时时间。我通过阅读源代码，发现Jedis是支持这一指令的，以下代码来自于 redis.clients.jedis.Jedis
/** * Set the string value as value of the key. The string can't be longer than 1073741824 bytes (1 GB). * @param key * @param value * @param nxxx NX|XX, NX -- Only set the key if it does not already exist. XX -- Only set the key if it already exist. * @param expx EX|PX, expire time units: EX = seconds; PX = milliseconds * @param time expire time in the units of <code>expx</code> * @return Status code reply */ public String set(final String key, final String value, final String nxxx, final String expx, final long time) {而RestTemplate在封装时，忽略了返回值。这个返回值表示了设值是否成功，在分布式锁等应用场景中是非常重要的。以下代码来自于org.springframework.data.redis.connection.RedisStringCommands
/** * Set {@code value} for {@code key} applying timeouts from {@code expiration} if set and inserting/updating values * depending on {@code option}. * * @param key must not be {@literal null}. * @param value must not be {@literal null}. * @param expiration can be {@literal null}. Defaulted to {@link Expiration#persistent()}. * @param option can be {@literal null}. Defaulted to {@link SetOption#UPSERT}. * @since 1.7 * @see <a href="http://redis.io/commands/set">Redis Documentation: SET</a> */ void set(byte[] key, byte[] value, Expiration expiration, SetOption option);如何在使用RedisTemplate的同时，获取Jedis实例，执行相关的方法？以下的方案是从RedisConnectionFactory中获取Redis连接（JedisConnection实现类），然后使用反射的方法从中取得了Jedis实例，即可直接执行其中的方法，供大家参考
@Autowired private RedisConnectionFactory connectionFactory; @RequestMapping("/greeting") public String greeting() { Field jedisField = ReflectionUtils.findField(JedisConnection.class, "jedis"); ReflectionUtils.makeAccessible(jedisField); System.out.println(connectionFactory.getConnection()); Jedis jedis = (Jedis) ReflectionUtils.getField(jedisField, connectionFactory.getConnection()); String result = jedis.set("test-key", "Hello world-", "NX", "EX", 1);代码执行后，返回字符串”OK”或者”null”，表示是否设值成功。
