PageImpl反序列化过程中出错：无法构造`org.SpringFramework.Data.Domain.PageImpl'的实例

Question

问题是在redis cache manager中使用Spring cache时，由于没有默认构造函数，无法反序列化Spring可分页响应

使用的Spring Boot版本为2.1.4版本

@Bean
public RedisCacheManager redisCacheManager(LettuceConnectionFactory lettuceConnectionFactory) {
    RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig().disableCachingNullValues()
        .serializeValuesWith(
                RedisSerializationContext.SerializationPair.fromSerializer(RedisSerializer.json()));

    redisCacheConfiguration.usePrefix();

    return RedisCacheManager.RedisCacheManagerBuilder.fromConnectionFactory(lettuceConnectionFactory)
            .cacheDefaults(redisCacheConfiguration).build();

}

@GetMapping
@Cacheable("Article_Response_Page")
public Page<Article> findAll(Pageable pageable) {
    return articleRepository.findAll(pageable);
}

 com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot 
 construct instance of `org.springframework.data.domain.PageImpl` (no 
 Creators, like default construct, exist): cannot deserialize from Object 
 value (no delegate- or property-based Creator)
 at [Source: (byte[])" 
 {"@class":"org.springframework.data.domain.PageImpl","content": 
 ["java.util.Collections$UnmodifiableRandomAccessList",[]],"pageable": 
 {"@class":"org.springframework.data.domain.PageRequest","sort":{"@class":"org.springframework.data.domain.Sort","sorted":false,"unsorted":true,"empty":true},"offset":0,"pageSize":20,"pageNumber":0,"paged":true,"unpaged":false},"totalPages":0,"totalElements":0,"last":true,"size":20,"number":0,"sort":{"@class":"org.springframework.data.domain.Sort","sorted":false,"uns"[truncated 73 bytes]; line: 1, column: 54]
at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:67) ~[jackson-databind-2.9.8.jar:2.9.8]

一定有更好的方法来解决这个问题，我想知道在spring cache中解决这类问题的最佳方法

这是移动到SPRING BOOT v2后的Jackson bug吗？

Answer 1

您可以使用PageImpl的包装器，然后：

public class PageImpl<T> extends org.springframework.data.domain.PageImpl<T> {

     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
     public PageImpl(@JsonProperty("content") List<T> content,
                @JsonProperty("number") int page,
                @JsonProperty("size") int size,
                @JsonProperty("totalElements") long total) {

        super(content, PageRequest.of(page, size), total);
    }
}