Shulou(Shulou.com)06/01 Report--

This article is about the methods that redis uses on projects. The editor thought it was very practical, so I shared it with you as a reference. Let's follow the editor and have a look.

Remembering that I wanted to integrate Redis into the JavaWeb project, I searched a lot of tutorials online that were not comprehensive, and now I finally figured it out, so I'd like to share it here.

Installation of 1.Redis

I will not talk about it here, there are many tutorials on the Internet, windows,Linux, my own is built on the server.

Graphical connection

Add a cache to the business logic

1.1. Interface encapsulation

The commonly used methods of operating redis extract an interface and create two implementation classes corresponding to stand-alone version and cluster version respectively.

1.1.1. Interface definition

# # jedisClient

Package cn.e3mall.common.jedis;import java.util.List;public interface JedisClient {String set (String key, String value); String get (String key); Boolean exists (String key); Long expire (String key, int seconds); Long ttl (String key); Long incr (String key); Long hset (String key, String field, String value); String hget (String key, String field); Long hdel (String key, String...) Field); Boolean hexists (String key, String field); List hvals (String key); Long del (String key);}

# JedisClientPool

Package cn.e3mall.common.jedis;import java.util.List;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;public class JedisClientPool implements JedisClient {private JedisPool jedisPool;public JedisPool getJedisPool () {return jedisPool;} public void setJedisPool (JedisPool jedisPool) {this.jedisPool = jedisPool;} @ Overridepublic String set (String key, String value) {Jedis jedis = jedisPool.getResource (); String result = jedis.set (key, value); jedis.close (); return result @ Overridepublic String get (String key) {Jedis jedis = jedisPool.getResource (); String result = jedis.get (key); jedis.close (); return result;} @ Overridepublic Boolean exists (String key) {Jedis jedis = jedisPool.getResource (); Boolean result = jedis.exists (key); jedis.close (); return result;} @ Overridepublic Long expire (String key, int seconds) {Jedis jedis = jedisPool.getResource (); Long result = jedis.expire (key, seconds); jedis.close (); return result } @ Overridepublic Long ttl (String key) {Jedis jedis = jedisPool.getResource (); Long result = jedis.ttl (key); jedis.close (); return result;} @ Overridepublic Long incr (String key) {Jedis jedis = jedisPool.getResource (); Long result = jedis.incr (key); jedis.close (); return result;} @ Overridepublic Long hset (String key, String field, String value) {Jedis jedis = jedisPool.getResource (); Long result = jedis.hset (key, field, value); jedis.close (); return result } @ Overridepublic String hget (String key, String field) {Jedis jedis = jedisPool.getResource (); String result = jedis.hget (key, field); jedis.close (); return result;} @ Overridepublic Long hdel (String key, String...) Field) {Jedis jedis = jedisPool.getResource (); Long result = jedis.hdel (key, field); jedis.close (); return result;} @ Overridepublic Boolean hexists (String key, String field) {Jedis jedis = jedisPool.getResource (); Boolean result = jedis.hexists (key, field); jedis.close (); return result;} @ Overridepublic List hvals (String key) {Jedis jedis = jedisPool.getResource (); List result = jedis.hvals (key); jedis.close (); return result } @ Overridepublic Long del (String key) {Jedis jedis = jedisPool.getResource (); Long result = jedis.del (key); jedis.close (); return result;}}

# JedisClientCluster

Package cn.e3mall.common.jedis;import java.util.List;import redis.clients.jedis.JedisCluster;public class JedisClientCluster implements JedisClient {private JedisCluster jedisCluster;public JedisCluster getJedisCluster () {return jedisCluster;} public void setJedisCluster (JedisCluster jedisCluster) {this.jedisCluster = jedisCluster;} @ Overridepublic String set (String key, String value) {return jedisCluster.set (key, value);} @ Overridepublic String get (String key) {return jedisCluster.get (key);} @ Overridepublic Boolean exists (String key) {return jedisCluster.exists (key) @ Overridepublic Long expire (String key, int seconds) {return jedisCluster.expire (key, seconds);} @ Overridepublic Long ttl (String key) {return jedisCluster.ttl (key);} @ Overridepublic Long incr (String key) {return jedisCluster.incr (key);} @ Overridepublic Long hset (String key, String field, String value) {return jedisCluster.hset (key, field, value);} @ Overridepublic String hget (String key, String field) {return jedisCluster.hget (key, field);} @ Overridepublic Long hdel (String key, String...) Field) {return jedisCluster.hdel (key, field);} @ Overridepublic Boolean hexists (String key, String field) {return jedisCluster.hexists (key, field);} @ Overridepublic List hvals (String key) {return jedisCluster.hvals (key);} @ Overridepublic Long del (String key) {return jedisCluster.del (key);}}

Configuration: applicationContext-redis.xml

Encapsulated code testing

Testpublic void testJedisClient () throws Exception {/ / initialize the Spring container ApplicationContext applicationContext = new ClassPathXmlApplicationContext ("classpath:spring/applicationContext-redis.xml"); / / get the JedisClient object JedisClient jedisClient = applicationContext.getBean (JedisClient.class) from the container; jedisClient.set ("first", "100"); String result = jedisClient.get ("first"); System.out.println (result);}

Add cach

1.1.1. Functional analysis

Add a cache when querying the list of contents.

1. Query the cache before querying the database.

2. Query the result and respond directly to the result.

3. Unable to query, there is no need to query the database in the cache.

4. add the query results to the cache.

5. Return the result.

Add cache: Key:cidValue: content list to redis. You need to convert the java object to json. Use hash to classify key. HASH_KEY:HASH |-KEY:VALUE |-KEY:VALUE

Note: adding a cache does not affect normal business logic.

Code implementation (implemented at the service layer)

@ Autowiredprivate JedisClient jedisClient;@Value ("${CONTENT_LIST}") private String CONTENT_LIST;@Overridepublic E3Result addContent (TbContent content) {/ / insert content data into the content table content.setCreated (new Date ()); content.setUpdated (new Date ()); / / insert into the database contentMapper.insert (content); / / cache synchronization to delete the corresponding data in the cache. JedisClient.hdel (CONTENT_LIST, content.getCategoryId (). ToString ()); return E3Result.ok ();} @ Overridepublic List getContentListByCid (long cid) {/ / query cache try {/ / if there is a direct response result in the cache String json = jedisClient.hget (CONTENT_LIST, cid + "); if (StringUtils.isNotBlank (json)) {List list = JsonUtils.jsonToList (json,TbContent.class); System.out.println (" data found from cache "); return list } catch (Exception e) {e.printStackTrace ();} / if there is no query database TbContentExample example = new TbContentExample (); Criteria criteria = example.createCriteria (); / / set query condition criteria.andCategoryIdEqualTo (cid); / / execute query List list = contentMapper.selectByExampleWithBLOBs (example); / / add results to cache try {System.out.println ("add results to cache"); jedisClient.hset (CONTENT_LIST, cid + ", JsonUtils.objectToJson (list) } catch (Exception e) {e.printStackTrace ();} return list;}

* * pay attention to cache synchronization

One more thing, hot cache, give it an expiration time (it's okay to be out of sync)

@ Overridepublic TbItem getItemById (long itemId) {/ / get goods to add cache, without reflecting the business logic, try-catchtry {System.out.println ("cache obtaining commodity information"); String json = jedisClient.get (REDIS_ITEM_PRE+ ":" + itemId+ ": BASE"); if (StringUtils.isNotBlank (json)) {TbItem tbItem = JsonUtils.jsonToPojo (json,TbItem.class); return tbItem;}} catch (Exception e) {e.printStackTrace () } / / not in cache, query database / / query / / TbItem tbItem = itemMapper.selectByPrimaryKey (itemId) according to primary key; TbItemExample example = new TbItemExample (); Criteria criteria = example.createCriteria (); / / set query condition criteria.andIdEqualTo (itemId); / / execute query List list = itemMapper.selectByExample (example); if (list! = null & & list.size () > 0) {/ / result is added to cache try {System.out.println ("cache adds commodity information") JedisClient.set (REDIS_ITEM_PRE+ ":" + itemId+ ": BASE", JsonUtils.objectToJson (list.get (0); / / set expiration time (1 hour) jedisClient.expire (REDIS_ITEM_PRE+ ":" + itemId+ ": BASE", TIEM_CACHE_EXPIRE);} catch (Exception e) {e.printStackTrace ();} return list.get (0);} return null;}

Data in redis:

{"itemId": 1231490, "created": 1425821627000, "updated": 1425821627000, "itemDesc": "warm reminder: Xiaomi 4 Unicom version has built-in operator software, Xiaomi 4 official Unicom version does not have built-in operator software. Product display Products Exhibition

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Sonny high picture quality

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"{" id ": 1231490," title ":" Xiaomi 4 White Unicom 3G mobile phone "," sellPoint ":" sold out! Stainless steel metal frame, 5-inch screen ultra-narrow edge, Snapdragon quad-core 2.5GHz processor, 3G RAM,1 thank you for reading! So much for sharing the methods used by redis on the project. I hope the above content can be of some help to you so that you can learn more knowledge. If you think the article is good, you can share it and let more people see it.

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