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This article mainly shows you the "Redis how to use RedisTemplate template class of common operations", the content is easy to understand, clear, hope to help you solve your doubts, the following let Xiaobian lead you to study and learn "Redis how to use RedisTemplate template class of common operations" this article.

I. Preface

Redis is one of the NoSQL (non-relational database) databases. The key-value storage system, or a cached key-value pair database, has the following characteristics:

Run based on memory with high performance

It supports distribution and can be expanded infinitely in theory.

Key-value storage system

Open source log database written in ANSI C, complying with BSD protocol, supporting network, memory-based and persistent, Key-Value database, and providing API in multiple languages

The main application scenarios include:

Caching systems, counters, message queuing systems, rankings, social networks and real-time systems, distributed locks and publish / subscribe messages, etc.

In the program, the common operation of Redis has a template class (or API) dedicated to manipulating Redis, which is RedisTemplate.

II. Brief introduction of Redis data structure

Redis can store the mapping between keys and five different types of data structures, namely String (string), List (list), Set (collection), Hash (hash), and Zset (ordered set).

Here is a brief introduction to these five types of data structures:

String string, integer, or floating-point number operates on the whole string or part of a string; objects and floating-point numbers perform increment or decrement List array linked lists, each node of which contains an element that pushes in or pops up elements from both ends of the linked list; trim the linked list based on offsets Read single or multiple elements; find or remove the unordered unorderedcollection of the element Set containing elements based on the value, and each element contained is unique and different to add, get, and remove a single element; check whether an element exists in a collection; calculate intersection, union, and subtraction Randomly get the element Hash from the collection by adding, fetching, and removing a single key-value pair in an unordered hash table containing key-value pairs; get the ordered mapping of all key-value pairs between Zset string members (member) and floating-point scores (score). The order of elements is determined by the size of the score; the element is added, acquired, or deleted according to the score range (range) or member.

RedisTemplate is located under the spring-data-redis package:

Package org.springframework.data.redis.core; public class RedisTemplate extends org.springframework.data.redis.core.RedisAccessor implements org.springframework.data.redis.core.RedisOperations

Inherits the RedisAccessor class and implements the RedisOperations generic key-value interface.

RedisTemplate can be referenced using annotations:

@ Autowiredprivate RedisTemplate redisTemplate; III. RedisTemplate's operation on 5 data structures

RedisTemplate uses the following methods to operate on five data structures:

RedisTemplate.opsForValue (); / / Operation string redisTemplate.opsForHash (); / / Operation hash redisTemplate.opsForList (); / / Operation list redisTemplate.opsForSet (); / / Operation set redisTemplate.opsForZSet (); / / Operation ordered set3.1 String string Operation / / set key and value values redisTemplate.opsForValue (). Set ("key", "value"); / / get the value String result = redisTemplate.opsForValue (). Get ("key"). ToString () through key 3.2 list array operations / / list array objects and add array values List list = new ArrayList (); list.add ("A1"); list.add ("a2"); list.add ("a3"); / / use the redisTemplate template class to add the list array collection to RedisredisTemplate.opsForList (). LeftPush ("listkey", list); / / use the redisTemplate template class to get the list collection List resultList = (List) redisTemplate.opsForList (). LeftPop ("listkey") from Redis according to key 3.3 Hash structure, map operations / / define Map collections and types Map map = new HashMap (); map.put ("key1", "value1"); map.put ("key2", "value2"); map.put ("key3", "value3"); / / set map to redis with redis template classes redisTemplate.opsForHash (). PutAll ("map", map); Map resultMap = redisTemplate.opsForHash (). Entries ("map") List reslutMapList = redisTemplate.opsForHash (). Values ("map"); Set resultMapSet = redisTemplate.opsForHash (). Keys ("map"); String value = (String) redisTemplate.opsForHash (). Get ("map", "key1"); 3.4 Set collection operation / / define a set set merge set set value SetOperations set = redisTemplate.opsForSet (); set.add ("set1", "22"); set.add ("set1", "33"); set.add ("set1", "44") / / get the object value in the set collection through key Set resultSet = redisTemplate.opsForSet (). Members ("set1"); this is all the content of the article "how to use the RedisTemplate template class in Redis". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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