Spring data Cassandra Rest Id must be assignable to Serializable!: null - spring-boot

Question

Given below Entity and Repository, I get Id must be assignable to Serializable!: null error when I access rest resource for repository.
curl -H 'Accept: application/json' http://localhost:8080/properties
{"cause":null,"message":"Id must be assignable to Serializable!: null"}
Groovy code
#Component
interface PropertyRepository extends CassandraRepository<Property, String> {
}
#Table("property_v1")
#Canonical
class Property {
#PrimaryKeyColumn(value = "name", type = PARTITIONED)
String name
#PrimaryKeyColumn(value = "environment", type = CLUSTERED)
String environment
#Column("value")
String value
}
I tried adding #Id annotation to primary key field but spring does not allow #Id and #PrimaryKeyColumn annotations on the same entity.
I get #Table types must not define both #Id and #PrimaryKeyColumn properties error.
How do I access spring data Cassandra entities over rest?
I tried using RepositoryRestResource annotation as well on Repository class but received same error.
#RepositoryRestResource(path = "/properties", collectionResourceRel = "properties")
Versions:
Spring boot: 2.0.1.RELEASE
Uses spring-boot-starter-data-cassandra, spring-boot-starter-data-rest moduldes
Exception Stacktrace:
java.lang.IllegalArgumentException: Id must be assignable to Serializable!: null
at org.springframework.util.Assert.instanceCheckFailed(Assert.java:637)
at org.springframework.util.Assert.isInstanceOf(Assert.java:537)
at org.springframework.data.rest.webmvc.support.RepositoryEntityLinks.linkToSingleResource(RepositoryEntityLinks.java:135)
at org.springframework.data.rest.core.support.DefaultSelfLinkProvider.createSelfLinkFor(DefaultSelfLinkProvider.java:68)
at org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler.getSelfLinkFor(PersistentEntityResourceAssembler.java:99)
at org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler.wrap(PersistentEntityResourceAssembler.java:76)
at org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler.toResource(PersistentEntityResourceAssembler.java:55)
at org.springframework.data.rest.webmvc.AbstractRepositoryRestController.entitiesToResources(AbstractRepositoryRestController.java:110)
at org.springframework.data.rest.webmvc.AbstractRepositoryRestController.toResources(AbstractRepositoryRestController.java:80)
at org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResource(RepositoryEntityController.java:209)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)

Answer 1

Figured out the issue.
If an entity class has a composite key, spring data rest works only if I have a dedicated class for Primary Key columns.
Changing the class structure to below, enabled rest resources for spring data entities. I used a nested static class for key. But it could be very well a public class of its own.
I feel this boiler plate should be removed from developers and instead spring could look into partition key column and use it as Id.
#Component
interface PropertyRepository extends CassandraRepository<Property, Property.PropertyKey> {
}
#Table("property_v1")
#Canonical
class Property {
#PrimaryKey
PropertyKey key
#Column("value")
String value
#PrimaryKeyClass
#Canonical
static class PropertyKey implements Serializable {
#PrimaryKeyColumn(value = "name", type = PARTITIONED)
String name
#PrimaryKeyColumn(value = "environment", type = CLUSTERED)
String environment
}
}