网站建设柒金手指下拉二一,公司网站设计规范,做网站的技术员,wordpress js代码插件Redis 批量操作
如果频繁地使用Redis#xff0c;比如在 for循环中调用 redis#xff0c;有时可能会报错#xff1a; Could not get a resource from the pool。
这是因为 Redis的连接数是有限的#xff0c;打开了Redis的连接#xff0c;用完记得要关闭#xff0c;如果连…Redis 批量操作
如果频繁地使用Redis比如在 for循环中调用 redis有时可能会报错 Could not get a resource from the pool。
这是因为 Redis的连接数是有限的打开了Redis的连接用完记得要关闭如果连接数不够了就会报错。
Redis 批量操作可以使用 RedisTemplate 的 execute()方法。
RedisTemplate 源码 org.springframework.data.redis.core.RedisOperations org.springframework.data.redis.core.RedisTemplate
RedisTemplate 的 execute()方法
org.springframework.data.redis.core.RedisTemplate#execute(org.springframework.data.redis.core.SessionCallback)
execute() 方法可以在一次连接中进行多个命令操作。执行完会自动关闭连接。 /*** Executes a Redis session. Allows multiple operations to be executed in the same session enabling transactional* capabilities through {link #multi()} and {link #watch(Collection)} operations.** param T return type* param session session callback. Must not be {literal null}.* return result object returned by the action or ttnull/tt*/Overridepublic T T execute(SessionCallbackT session) {Assert.isTrue(initialized, template not initialized; call afterPropertiesSet() before using it);Assert.notNull(session, Callback object must not be null);RedisConnectionFactory factory getRequiredConnectionFactory();// 打开连接RedisConnectionUtils.bindConnection(factory, enableTransactionSupport);try {return session.execute(this);} finally {//执行完会自动关闭连接RedisConnectionUtils.unbindConnection(factory);}}execute()的SessionCallback参数和RedisCallback参数
SessionCallback 比 RedisCallck 更好些优先使用 SessionCallback 。
使用SessionCallback , 还可以配合multi() 和 watch() 进行事务操作。
/*** Executes the given action within a Redis connection. Application exceptions thrown by the action object get* propagated to the caller (can only be unchecked) whenever possible. Redis exceptions are transformed into* appropriate DAO ones. Allows for returning a result object, that is a domain object or a collection of domain* objects. Performs automatic serialization/deserialization for the given objects to and from binary data suitable* for the Redis storage. Note: Callback code is not supposed to handle transactions itself! Use an appropriate* transaction manager. Generally, callback code must not touch any Connection lifecycle methods, like close, to let* the template do its work.** param T return type* param action callback object that specifies the Redis action. Must not be {literal null}.* return a result object returned by the action or ttnull/tt*/
Nullable
T T execute(RedisCallbackT action);/*** Executes a Redis session. Allows multiple operations to be executed in the same session enabling transactional* capabilities through {link #multi()} and {link #watch(Collection)} operations.** param T return type* param session session callback. Must not be {literal null}.* return result object returned by the action or ttnull/tt*/
Nullable
T T execute(SessionCallbackT session);execute() 使用示例 Autowiredprivate StringRedisTemplate stringRedisTemplate;public void testExecute() {String userId userId;stringRedisTemplate.opsForValue().set(userId123, lin);stringRedisTemplate.opsForValue().set(userId456, wu);stringRedisTemplate.opsForValue().set(userId789, chen);MapString, String map new HashMap();stringRedisTemplate.execute(new SessionCallbackString() {Overridepublic K, V String execute(NonNull RedisOperationsK, V redisOperations) throws DataAccessException {ListString list Arrays.asList(123, 456, 789);for (String id : list) {String key userId id;String value (String) redisOperations.opsForValue().get(key);map.put(key, value);}return null;}});map.forEach((k, v) - System.out.println(k ,val: v));}
