Projections require Entity Id field to not throw exception while instantiating

[VariabileAleatoria]

Issue Description

When creating interface projections that only expose specific fields (closed projections), omitting the entity's @Id field can result in runtime errors during proxy creation, even when the projected fields contain valid non-null data.

Entity

@Data
@Builder
@Table("file")
public class File {
    @Id
    private Long id;
    private String fileId;
    private Long uploaderId;
    private LocalDateTime uploadDate;
    private String fullName;
    @Builder.Default
    @MappedCollection(idColumn = "file_id")
    private Set<Document> documents = new HashSet<>();
}

Projection

public interface FilePreview {
    String getFileId();
    LocalDateTime getUploadDate();
}

Repository

public interface FileRepository extends CrudRepository<File, Long> {
    List<FilePreview> findBy();
}

When invoking findBy an java.lang.IllegalStateException is thrown with message Identifier value must not be null at this point.

Modifying the projection to

public interface FilePreview {
    Long getId();
    String getFileId();
    LocalDateTime getUploadDate();
}

results in the method not throwing exception.

The documentation does not mention anywhere this as an intended behaviour and it's not clear why would it be needed.

[mp911de]

Care to attach the full stack trace?

[VariabileAleatoria]

stack

sure, class names were translated to english to file the issue

java.lang.IllegalStateException: Identifier value must not be null at this point
        at org.springframework.util.Assert.state(Assert.java:79)
        at org.springframework.data.jdbc.core.convert.MappingJdbcConverter$ResolvingRelationalPropertyValueProvider.getPropertyValue(MappingJdbcConverter.java:375)
        at org.springframework.data.jdbc.core.convert.MappingJdbcConverter$ResolvingRelationalPropertyValueProvider.getPropertyValue(MappingJdbcConverter.java:306)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter$2.getPropertyValue(MappingRelationalConverter.java:495)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter$2.getPropertyValue(MappingRelationalConverter.java:471)
        at org.springframework.data.mapping.model.PersistentEntityParameterValueProvider.getParameterValue(PersistentEntityParameterValueProvider.java:72)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter$ConvertingParameterValueProvider.getParameterValue(MappingRelationalConverter.java:1244)
        at org.springframework.data.mapping.model.ValueExpressionParameterValueProvider.getParameterValue(ValueExpressionParameterValueProvider.java:56)
        at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.extractInvocationArguments(ClassGeneratingEntityInstantiator.java:301)
        at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator$EntityInstantiatorAdapter.createInstance(ClassGeneratingEntityInstantiator.java:273)
        at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:98)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter.read(MappingRelationalConverter.java:462)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter.readAggregate(MappingRelationalConverter.java:357)
        at org.springframework.data.relational.core.conversion.MappingRelationalConverter.readAggregate(MappingRelationalConverter.java:320)
        at org.springframework.data.jdbc.core.convert.MappingJdbcConverter.readAndResolve(MappingJdbcConverter.java:283)
        at org.springframework.data.jdbc.core.convert.EntityRowMapper.mapRow(EntityRowMapper.java:65)
        at org.springframework.data.jdbc.repository.support.JdbcQueryLookupStrategy$PostProcessingRowMapper.mapRow(JdbcQueryLookupStrategy.java:367)
        at org.springframework.data.jdbc.repository.query.AbstractJdbcQuery$ConvertingRowMapper.mapRow(AbstractJdbcQuery.java:207)
        at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:94)
        at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:61)
        at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:733)
        at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:658)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:723)
        at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:748)
        at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:178)
        at org.springframework.data.jdbc.repository.query.AbstractJdbcQuery.lambda$createSingleReadingQueryExecution$3(AbstractJdbcQuery.java:149)
        at org.springframework.data.jdbc.repository.query.PartTreeJdbcQuery.execute(PartTreeJdbcQuery.java:150)
        at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:170)
        at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:158)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:170)
        at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:149)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:380)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:138)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:223)
        at jdk.proxy2/jdk.proxy2.$Proxy91.findBy(Unknown Source)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
        at java.base/java.lang.reflect.Method.invoke(Method.java:565)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:359)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:196)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
        at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:138)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
        at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:223)
        at jdk.proxy2/jdk.proxy2.$Proxy91.findBy(Unknown Source)
        at it.liguriadigitale.tribunali_be.service.FascicoloServiceTest.getFascicoloPreview(FascicoloServiceTest.java:46)
        at java.base/java.lang.reflect.Method.invoke(Method.java:565)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)