通过上一节,我们了解了redisTemplate和StringRedisTemplate的区别,那么有没有什么办法,可以序列化对象,可读性又强呢?
spring-data-redis提供如下几种选择:
编写测试代码:
@Test
public void testSerial(){
UserPO userPO = new UserPO(1111L,"小明_testRedis1",25);
List<Object> list = new ArrayList<>();
for(int i=0;i<200;i++){
list.add(userPO);
}
JdkSerializationRedisSerializer j = new JdkSerializationRedisSerializer();
GenericJackson2JsonRedisSerializer g = new GenericJackson2JsonRedisSerializer();
Jackson2JsonRedisSerializer j2 = new Jackson2JsonRedisSerializer(List.class);
Long j_s_start = System.currentTimeMillis();
byte[] bytesJ = j.serialize(list);
System.out.println("JdkSerializationRedisSerializer序列化时间:"+(System.currentTimeMillis()-j_s_start) + "ms,序列化后的长度:" + bytesJ.length);
Long j_d_start = System.currentTimeMillis();
j.deserialize(bytesJ);
System.out.println("JdkSerializationRedisSerializer反序列化时间:"+(System.currentTimeMillis()-j_d_start));
Long g_s_start = System.currentTimeMillis();
byte[] bytesG = g.serialize(list);
System.out.println("GenericJackson2JsonRedisSerializer序列化时间:"+(System.currentTimeMillis()-g_s_start) + "ms,序列化后的长度:" + bytesG.length);
Long g_d_start = System.currentTimeMillis();
g.deserialize(bytesG);
System.out.println("GenericJackson2JsonRedisSerializer反序列化时间:"+(System.currentTimeMillis()-g_d_start));
Long j2_s_start = System.currentTimeMillis();
byte[] bytesJ2 = j2.serialize(list);
System.out.println("Jackson2JsonRedisSerializer序列化时间:"+(System.currentTimeMillis()-j2_s_start) + "ms,序列化后的长度:" + bytesJ2.length);
Long j2_d_start = System.currentTimeMillis();
j2.deserialize(bytesJ2);
System.out.println("Jackson2JsonRedisSerializer反序列化时间:"+(System.currentTimeMillis()-j2_d_start));
}
运行测试结果:
JdkSerializationRedisSerializer序列化时间:8ms,序列化后的长度:1325
JdkSerializationRedisSerializer反序列化时间:4
GenericJackson2JsonRedisSerializer序列化时间:52ms,序列化后的长度:17425
GenericJackson2JsonRedisSerializer反序列化时间:60
Jackson2JsonRedisSerializer序列化时间:4ms,序列化后的长度:9801
Jackson2JsonRedisSerializer反序列化时间:4
JdkSerializationRedisSerializer序列化后长度最小,Jackson2JsonRedisSerializer效率最高。
如果综合考虑效率和可读性,牺牲部分空间,推荐key使用StringRedisSerializer,保持的key简明易读;value可以使用Jackson2JsonRedisSerializer
如果空间比较敏感,效率要求不高,推荐key使用StringRedisSerializer,保持的key简明易读;value可以使用JdkSerializationRedisSerializer
package com.example.demo.config.redisConfig;
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;
@Configuration
public class RedisConfig {
@Bean(name = "redisTemplate")
public RedisTemplate<String, Object> getRedisTemplate(RedisConnectionFactory factory) {
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();
redisTemplate.setConnectionFactory(factory);
redisTemplate.setKeySerializer(new StringRedisSerializer()); // key的序列化类型
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);
redisTemplate.setValueSerializer(jackson2JsonRedisSerializer); // value的序列化类型
return redisTemplate;
}
}
注: new Jackson2JsonRedisSerializer(Object.class)需要指明类型,例如:new Jackson2JsonRedisSerializer(User.class),否则会报错:
java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to com.example.demo.bean.User。
或者开启默认类型:
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
这种方式存储时会自动带上类的全路径,占用部分空间:
@Configuration
public class RedisConfig {
@Bean(name = "redisTemplate")
public RedisTemplate<String, Object> getRedisTemplate(RedisConnectionFactory factory) {
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();
redisTemplate.setConnectionFactory(factory);
redisTemplate.setKeySerializer(new StringRedisSerializer()); // key的序列化类型
redisTemplate.setValueSerializer(new JdkSerializationRedisSerializer()); // value的序列化类型
return redisTemplate;
}
}
注:该方式,对象需要实现接口:Serializable
@RunWith(SpringRunner.class)
@SpringBootTest
@WebAppConfiguration
public class RedisTest {
@Resource
private RedisTemplate redisTemplate;
@Test
public void testRedis1(){
User user = new User();
user.setAge(11);
user.setName("我是小王1");
redisTemplate.opsForValue().set("user37",user);
System.out.println(redisTemplate.getValueSerializer());
System.out.println(redisTemplate.getKeySerializer());
User result = (User) redisTemplate.opsForValue().get("user37");
System.out.println(result);
}
}