Question

我想使用spring缓存，并将其添加到findAll（Pageable pageable）上，如下所示：

@CacheConfig(cacheNames = {"familyUserDao"})
public interface FamilyUserDao extends JpaRepository<FamilyUser,Long> {
    @Override
    @Cacheable(key = "methodName +#p0")
    Page<FamilyUser> findAll(Pageable pageable);
}

我打电话的时候
页面familyUserPage = familyUserDao.findAll（pageable）; 第一次可以，但是当我第二次打电话时，它像下面这样扔：

org.springframework.data.redis.serializer.SerializationException: Could not         read JSON: Can not construct instance of org.springframework.data.domain.PageImpl: no suitable constructor found, can  not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)
 at [Source: [B@7fae8571; line: 1, column: 46]; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of org.springframework.data.domain.PageImpl: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)
 at [Source: [B@7fae8571; line: 1, column: 46]
at org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer.deserialize(Jackson2JsonRedisSerializer.java:73)

实际上这是一个反序列化问题，Page的默认实现类是PageImpl。但是它没有默认的构造函数，那么如何解决呢？

Answer 1

在调用方法时，您必须传递参数，这是Page类型和整数类型的两个属性，例如continuation：

Page familyUserPage = familyUserDao.findAll (int page, int size);

要显示前10个对象，请将页面置于0并将大小设为10，将10跟随页面设为1并将大小设为10 ...

当我调用spring data JPA分页查询时，抛出“ PageImpl：找不到合适的构造函数，无法反序列化”

1 个答案: