SpringBoot2.0配置Redis實現緩存和鍵值的序列化

1、基於maven管理的Java項目，需要在pom文件中加入redis所需要的的依賴

        <!-- redis 依賴-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <!--集成redis所需common-pool2  -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
            <version>2.5.0</version>
        </dependency>
        <!--redis 對象序列化器-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.47</version>
        </dependency>

2、新建一個配置類RedisConfig，實現鍵值的序列化

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * @author： SUN
 * @version: 1.0
 * @date： 2019/12/30 10:22
 * @description： redis配置類 實現key和value的序列化
 */

@Configuration
public class RedisConfig {


    /**
     * @param redisConnectionFactory
     * @return 自定義redisTemplate，自帶的bean沒有序列化器
     */
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);

        // 使用Jackson2JsonRedisSerialize 替換默認序列化   
        //將數據信息轉化爲json格式  redis服務器中可以查看數據信息
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);

        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);

        // 設置value的序列化規則和 key的序列化規則
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);
        redisTemplate.afterPropertiesSet();
        return redisTemplate;

    }
}

 3、通過測試類實現本地實體類或集合對象的存儲和讀取

import com.touchspring.ssdt.rfid.domain.entity.sys.SysWorker;
import com.touchspring.ssdt.rfid.repository.sys.SysWorkerRepository;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ValueOperations;

import java.util.List;

/**
 * @author： SUN
 * @version: 1.0
 * @date： 2019/12/30 11:13
 * @description：
 */
public class newTest extends TmallApplicationTests {

    @Autowired
    private SysWorkerRepository sysWorkerRepository;
    @Autowired
    private RedisTemplate redisTemplate;


    @Test
//    @Ignore("not ready yet")  此註解將不再執行方法內容
    public void testRedisPush() {
        List<SysWorker> sysWorkerList = sysWorkerRepository.findAll();
        SysWorker sysWorker = sysWorkerList.get(0);

        // ValueOperations是操作簡單的value例如String工具類
        ValueOperations valueOperations = redisTemplate.opsForValue();
        valueOperations.set("workerKey", sysWorker);

        // HashOperations是操作value爲Map的工具類
        HashOperations hashOperations = redisTemplate.opsForHash();
        hashOperations.put("workerListKey", "1", sysWorkerList);

    }

    @Test
    public void testRedisGet() {
        //  根據key值讀取對象
        ValueOperations valueOperations = redisTemplate.opsForValue();
        SysWorker sysWorker = (SysWorker) valueOperations.get("workerKey");
        System.out.println("- - - - " + sysWorker.toString());
        
        //  根據key值讀取對象
        HashOperations hashOperations = redisTemplate.opsForHash();
        List<SysWorker> sysWorkers = (List<SysWorker>) hashOperations.get("workerListKey", "1");
        System.out.println("- - - - " + sysWorkers.toString());
    }

}

4、redis存儲如下

• （1）ValueOperations

• （2）HashOperations

5、存儲到redis數據中如果包括日期（LocalDateTime），則從redis讀取解析數據時可能存在報錯，無法實現LocalDateTime日期的反序列化操作，則需要根據以下方式在日期屬性上添加註解進行處理

• 1、LocalDateTime屬性加上註解

@JsonDeserialize(using = LocalDateTimeDeserializer.class)
@JsonSerialize(using = LocalDateTimeSerializer.class)

public class Demo {
    private Long id;
    private String name;
    @JsonDeserialize(using = LocalDateTimeDeserializer.class)
    @JsonSerialize(using = LocalDateTimeSerializer.class)
    private LocalDateTime time;
    ......
    }

• 2、若未進行處理，在redis中存儲的LocalDateTime格式爲

{
  "@class": "com.karmay3d.Demo",
  "id": 10000000001,
  "name": "測試序列化",
  "time": {
    "dayOfMonth": 15,
    "dayOfWeek": "TUESDAY",
    "dayOfYear": 227,
    "month": "AUGUST",
    "monthValue": 8,
    "year": 2017,
    "hour": 14,
    "minute": 45,
    "second": 51,
    "nano": 921000000,
    "chronology": {
      "@class": "java.time.chrono.IsoChronology",
      "id": "ISO",
      "calendarType": "iso8601"
    }
  }
}

• 3、使用註解處理後 redis再次存入之後結構

{
  "@class": "com.karmay3d.Demo",
  "id": 10000000001,
  "name": "測試序列化",
  "time": [2017,8,15,14,57,37,525000000]
}

• 4、之後反序列化就可以取出實體對象了。