我一直在嘗試更改 spring-boot redis 緩存的默認(rèn)序列化程序，因?yàn)槲蚁霃?Default 更改為 Jackson2Json 實(shí)現(xiàn)之一。Jackson2Json 庫(kù)中有兩個(gè)實(shí)現(xiàn)，其中之一是：GenericJackson2JsonRedisSerializer，我可以在以下 bean 實(shí)例化中使用它：@Bean@Primarypublic RedisCacheConfiguration defaultCacheConfig(ObjectMapper objectMapper) { return RedisCacheConfiguration.defaultCacheConfig() .serializeKeysWith( SerializationPair.fromSerializer( new StringRedisSerializer() ) ) .serializeValuesWith( SerializationPair.fromSerializer( new GenericJackson2JsonRedisSerializer(objectMapper) ) ) .prefixKeysWith("");}當(dāng)我使用此序列化程序時(shí)，序列化工作正常，所有內(nèi)容都存儲(chǔ)在 redis 服務(wù)器上，但是當(dāng)我嘗試反序列化存儲(chǔ)在 redis 服務(wù)器上的 JSON 時(shí)，我收到以下異常：java.util.LinkedHashMap cannot be cast to tutorial.Person with root causejava.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to tutorial.Person緩存的使用方式如下：@Cacheable(cacheNames = "person", key = "'person:'.concat(#post.id)")public Person findPostAuthor(Post post){}序列化程序不知道如何從 LinkedHashMap 轉(zhuǎn)換為 Person，我怎么能告訴他怎么做呢？我嘗試使用的另一個(gè)序列化器是 Jackson2JsonRedisSerializer：@Bean@Primarypublic RedisCacheConfiguration defaultCacheConfig(ObjectMapper objectMapper) { Jackson2JsonRedisSerializer<Person> serializer = new Jackson2JsonRedisSerializer<>(Person.class); serializer.setObjectMapper(objectMapper); return RedisCacheConfiguration.defaultCacheConfig() .serializeKeysWith( SerializationPair.fromSerializer( new StringRedisSerializer() ) ) .serializeValuesWith( SerializationPair.fromSerializer( serializer ) ) .prefixKeysWith("");}這樣，我必須為保存在 redis 緩存中的每個(gè)對(duì)象聲明一個(gè) bean，但我可以正確序列化/反序列化。當(dāng)我直接在 redis 緩存中插入 JSON 時(shí)，我無(wú)法使用此序列化程序?qū)ζ溥M(jìn)行反序列化，序列化程序只會(huì)給我一個(gè) Person 對(duì)象，其名稱、電子郵件和 id 屬性為空。有沒(méi)有辦法來(lái)解決這個(gè)問(wèn)題？如果有辦法改善我的問(wèn)題，請(qǐng)告訴我。
3 回答
紅糖糍粑
TA貢獻(xiàn)1815條經(jīng)驗(yàn) 獲得超6個(gè)贊
GenericJackson2JsonRedisSerializer假設(shè)杰克遜的默認(rèn)類型。當(dāng)您GenericJackson2JsonRedisSerializer使用ObjectMapper實(shí)例創(chuàng)建時(shí)，請(qǐng)確保配置默認(rèn)類型 ( enableDefaultTyping(…))。
默認(rèn)類型最適合非最終類型，并且需要在所有 JSON 有效負(fù)載中為類型提供一致的屬性名稱，以便 Jackson 可以識(shí)別要反序列化的適當(dāng)類型。
默認(rèn)類型使用動(dòng)態(tài)類型標(biāo)記，如果您的數(shù)據(jù)源（Redis 實(shí)例）不完全受信任，那么這可能會(huì)成為安全問(wèn)題。
Jackson2JsonRedisSerializer固定到特定類型并消除動(dòng)態(tài)類型風(fēng)險(xiǎn)。
斯蒂芬大帝
TA貢獻(xiàn)1827條經(jīng)驗(yàn) 獲得超8個(gè)贊
您可以使用 Spring Data Redis
添加依賴項(xiàng)：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
啟用緩存和使用 Jackson2JsonRedisSerializer
package com.redis.demo.redisdemo.config;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.cache.RedisCacheWriter;
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.RedisSerializationContext;
import org.springframework.data.redis.serializer.StringRedisSerializer;
@EnableCaching
@Configuration
public class RedisConfig extends CachingConfigurerSupport {
@Autowired
private RedisConnectionFactory redisConnectionFactory;
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
serializer.setObjectMapper(objectMapper);
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
redisTemplate.setKeySerializer(new StringRedisSerializer());
redisTemplate.setValueSerializer(serializer);
redisTemplate.setHashKeySerializer(new StringRedisSerializer());
redisTemplate.setHashValueSerializer(serializer);
redisTemplate.afterPropertiesSet();
return redisTemplate;
}
@Bean
public RedisCacheManager redisCacheManager(RedisTemplate redisTemplate) {
RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisTemplate.getConnectionFactory());
RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(redisTemplate.getValueSerializer()));
return new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
}
}
在方法中添加可緩存注釋以緩存在redis中
@Cacheable(value = "employee", key = "#id")
public Employee getEmployee(Integer id) {
log.info("Get Employee By Id: {}", id);
Optional<Employee> employeeOptional = employeeRepository.findById(id);
if (!employeeOptional.isPresent()) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Id Not foud");
}
return employeeOptional.get();
}
眼眸繁星
TA貢獻(xiàn)1873條經(jīng)驗(yàn) 獲得超9個(gè)贊
我知道這個(gè)問(wèn)題被問(wèn)到已經(jīng)很久了，但可能還有人需要答案。
我有同樣的問(wèn)題，我使用JdkSerializationRedisSerializer而不是解決它GenericJackson2JsonRedisSerializer。
我的RedisCacheConfiguration豆子看起來(lái)像：
return RedisCacheConfiguration.defaultCacheConfig()
.entryTtl(Duration.ofHours("your-long-value"))
.serializeKeysWith(SerializationPair.fromSerializer(new StringRedisSerializer()))
.serializeValuesWith(SerializationPair.fromSerializer(new JdkSerializationRedisSerializer()));添加回答
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