1. Create a new spring project and check the necessary component web DataJdbc mysql redis
2. Download redis, configure config file
Comment bind 127, allow all ip access
Protected-mode yes change to no to cancel the protection mechanism and allow external network access
daemonize no change yes background operation
Uncomment requirepass to set the password
Run redis-server.exe [configuration file path]
3. Configuration file properties, write MVC three layers
# configure data source spring.datasource.url=jdbc:mysql://localhost:3306/bjpowernode?serverTimezone=UTC &useSSL=false &characterEncoding=utf-8 spring.datasource.username=root spring.datasource.password=123456 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver # Configure MyBatis mybatis.mapper-locations=classpath:mapper/*.xml mybatis.configuration.map-underscore-to-camel-case=true #redis spring.redis.host=127.0.0.1 spring.redis.port=6379 spring.redis.password=123456 spring.redis.timeout=600000 #Timeout
Write redis configuration class
@Configuration
public class RedisConfig {
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
return redisTemplate;
}
}
Write a three-tier architecture, postman to test the database
@RestController
@RequestMapping("test")
public class T {
@Autowired
EmpService empService;
@GetMapping("t1")
@ResponseBody
public List<Emp> t1(){
List <Emp> e=empService.getemp();
return e;
}
}
@Service
public interface EmpService {
List<Emp> getemp();
}
@Service
public class EmpServiceImpl implements EmpService {
@Autowired
EmpDAO empDAO;
@Autowired
RedisTemplate redisTemplate;
@Override
public List<Emp> getemp() {
List<Emp> emps= (List<Emp>) redisTemplate.opsForValue().get("getemp");
if (emps!=null){
System.out.println("Have read the cache~~~~~~~~~");
return emps;
}
System.out.println("Expired no read cache~~~");
List<Emp> getemp = empDAO.getemp();
redisTemplate.opsForValue().set("getemp",getemp,10, TimeUnit.SECONDS);//Manually set the expiration time
return get temp;
}
}
@Mapper //You can use @MapperScan("scan dao/mapper path") on the startup class
public interface EmpDAO {
List<Emp> getemp();
}
XML
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.demo2.dao.EmpDAO">
<select id="getemp" resultType="com.demo2.pojo.Emp">
SELECT * FROM emp
</select>
</mapper>
4. Additional: redis tools (optional) copied online
/**
* @author yu_xuanyuan
* @date 2022/9/23 10:16
*/
@Component
public class RedisUtil {
@Autowired
RedisTemplate<String, Object> redisTemplate;
/**
*setex
* @param key key
* @param value value
* @param time expiration time
*/
public void setex(String key,Object value,long time){
redisTemplate.opsForValue().set(key, value, time, TimeUnit.SECONDS);
}
/**
* set
* String type set, no expiration time
* @param key key
* @param value value
*/
public void set(String key, Object value){
redisTemplate.opsForValue().set(key,value);
}
/**
* Set key and value in batches
* @param map key and value set
*/
public void mset(Map<String,Object> map){
redisTemplate.opsForValue().multiSet(map);
}
/**
* Set if key does not exist
* @param key key
* @param value value
* @return return success
*/
public Boolean setnx(String key, Object value){
return redisTemplate.opsForValue().setIfAbsent(key, value);
}
/**
* Batch insert key, if key does not exist
* @param map key and value set
* @return success
*/
public Boolean msetnx(Map<String,Object> map){
return redisTemplate.opsForValue().multiSetIfAbsent(map);
}
/**
* String type get
* @param key key
* @return returns the object corresponding to value
*/
public Object get(String key){
return redisTemplate.opsForValue().get(key);
}
/**
* Delete the corresponding key
* @param key key
* @return Returns whether the deletion is successful
*/
public Boolean del(String key){
return redisTemplate.delete(key);
}
/**
* Batch delete keys
* @param keys collection of keys
* @return Return the number of successful deletions
*/
public Long del(List<String> keys){
return redisTemplate.delete(keys);
}
/**
* Set an expiration time for a key
* @param key key
* @param time expiration time
* @return Returns whether the setting is successful
*/
public Boolean expire(String key, long time){
return redisTemplate. expire(key, time, TimeUnit. SECONDS);
}
/**
* Return the expiration time of a key
* @param key key
* @return Returns the remaining expiration time of the key
*/
public Long ttl(String key){
return redisTemplate. getExpire(key);
}
/**
* Return whether the key exists
* @param key key
* @return whether the key exists
*/
public Boolean exists(String key){
return redisTemplate.hasKey(key);
}
/**
* Add the delta value to the value of the key
* @param key key
* @param delta parameter
* @return return the value of key + delta
*/
public Long incrby(String key, long delta){
return redisTemplate.opsForValue().increment(key, delta);
}
/**
* Subtract delta from the value of key
* @param key key
* @param delta parameter
* @return return key - delta value
*/
public Long decrby(String key, long delta){
return redisTemplate.opsForValue().decrement(key, delta);
}
//hash type
/**
* set hash type
* @param key key
* @param hashKey hashKey
* @param value value
*/
public void hset(String key, String hashKey, Object value){
redisTemplate.opsForHash().put(key, hashKey, value);
}
/**
* set hash type, and set the expiration time
* @param key key
* @param hashKey hashKey
* @param value value
* @param time expiration time
* @return return success
*/
public Boolean hset(String key, String hashKey, Object value, long time){
hset(key, hashKey, value);
return expire(key, time);
}
/**
* batch setting hash
* @param key key
* @param map collection of hashKey and value
* @param time expiration time
* @return success
*/
public Boolean hmset(String key, Map<String,Object> map, long time){
redisTemplate.opsForHash().putAll(key, map);
return expire(key, time);
}
/**
* Get the value of hash type
* @param key key
* @param hashKey hashKey
* @return returns the corresponding value
*/
public Object hget(String key, String hashKey){
return redisTemplate.opsForHash().get(key, hashKey);
}
/**
* Get all the hash values and hashKey under the key
* @param key key
* @return return data
*/
public Map<Object,Object> hgetall(String key){
return redisTemplate.opsForHash().entries(key);
}
/**
* batch deletion
* @param key key
* @param hashKey hashKey array collection
*/
public void hdel(String key, Object... hashKey){
redisTemplate.opsForHash().delete(key, hashKey);
}
/**
* Determine whether there is a hashKey
* @param key key
* @param hashKey hashKey
* @return exists
*/
public Boolean hexists(String key, String hashKey){
return redisTemplate.opsForHash().hasKey(key, hashKey);
}
}