Spring Data implementing custom repository with abstract class in the middle

Question

I need to implement filtering to all entities' repositories.

The filtering follows the same scenario, differing only in Filter and Entity params.

So now I have my filter interface:

interface RepositoryFilter<Entity, Filter> {
 fun findAllByFilter(filter: Filter, pageable: Pageable): PageImpl<Entity>
}

An abstract class which implements several methods used in findAllByFilter implementation:

abstract class AbstractRepositoryFilter<Entity, Filter>(
 private val jdbcTemplate: NamedParameterJdbcTemplate
) : RepositoryFilter<Entity, Filter> {
 override fun findAllByFilter(filter: Filter, pageable: Pageable): RestResponsePage<Entity> {
 val sql = initSqlQuery() // to be implemented in concrete class
 val params = mutableMapOf<String, Any>() 
 appendFilterParams(filter, sql, params) // to be implemented in concrete class
 val total = countFiltered(sql, params) // is implemented in AbstractRepositoryFilter
 val result = collectFiltered(sql, params) // to be implemented in concrete class
 return RestResponsePage(result, pageable, total)
 }
}

A concrete class, that implements functionality for concrete Entity (Event):

class RepositoryFilterImpl(
 jdbcTemplate: NamedParameterJdbcTemplate
) : AbstractRepositoryFilter<Event, EventFilter>(jdbcTemplate) {
 override fun initSqlQuery(): StringBuilder {
 // implemention 
 }
 override fun appendFilterParams(filter: EventFilter, sql: StringBuilder, params: MutableMap<String, Any>) {
 // implemention 
 }
 override fun collectFiltered(sql: StringBuilder, params: MutableMap<String, Any>): List<Event>
 {
 // implemention 
 }
}

The result repository:

@Repository
interface EventRepository : CrudRepository<Event, Long>, RepositoryFilter<Event, EventFilter>

However, I get the same mistake, trying to compile this:

Caused by: org.springframework.data.mapping.PropertyReferenceException: No property 'filter' found for type 'Event'
 at org.springframework.data.mapping.PropertyPath.<init>(PropertyPath.java:94) ~[spring-data-commons-3.4.2.jar:3.4.2]
 at org.springframework.data.mapping.PropertyPath.create(PropertyPath.java:455) ~[spring-data-commons-3.4.2.jar:3.4.2]

I want to avoid boilerplate code, that's why I tried to use an abstract class...

• Svetlana: I was trying to follow an example provided in Spring's Custom Repository Implementations. There is a UserRepository (my EventRepository), which extends CustomizedSave interface (my RepositoryFilter). In turn, CustomizedSave is implemented by CustomizedSaveImpl (my RepositoryFilterImpl as i hope)

Answer 1

I think you should check , you annotate "@EnableJpaRepositories" at configuration.