ListArrayTypeDescriptor doesn't support Spring JPA Projections #562

hypersistence-utils-hibernate-55/src/main/java/io/hypersistence/utils/hibernate/type/array/internal/ListArrayTypeDescriptor.java

@@ -151,6 +151,10 @@ public void setParameterValues(Properties parameters) {
     }
 
     private Collection newPropertyCollectionInstance() {
+        // propertyClass is not defind for the projection
+        if(propertyClass == null){
+            return new ArrayList();
+        }
         if(List.class.isAssignableFrom(propertyClass)) {
             return new ArrayList();
         } else if(Set.class.isAssignableFrom(propertyClass)) {

hypersistence-utils-hibernate-55/src/test/java/io/hypersistence/utils/spring/repo/projection/PostRepository.java

@@ -0,0 +1,31 @@
+package io.hypersistence.utils.spring.repo.projection;
+
+import io.hypersistence.utils.spring.domain.Post;
+import io.hypersistence.utils.spring.repository.BaseJpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.stereotype.Repository;
+
+import javax.annotation.Nullable;
+import java.util.List;
+
+/**
+ * @author Vlad Mihalcea
+ */
+@Repository
+public interface PostRepository extends BaseJpaRepository<Post, Long> {
+
+    @Query(value = "select p.title as title, array_agg(p.slug) as slugs " +
+            "from Post p " +
+            "group by p.title",
+            nativeQuery = true)
+    @Nullable
+    List<TestProjection> findAllSlugGroupedByTitle();
+
+
+    interface TestProjection {
+        @Nullable
+        String getTitle();
+        @Nullable
+        List<String> getSlugs();
+    }
+}

hypersistence-utils-hibernate-55/src/test/java/io/hypersistence/utils/spring/repo/projection/ProjectionSpringDataJPABaseConfiguration.java

@@ -0,0 +1,45 @@
+package io.hypersistence.utils.spring.repo.projection;
+
+import io.hypersistence.utils.hibernate.type.array.ListArrayType;
+import io.hypersistence.utils.spring.config.AbstractSpringDataJPAConfiguration;
+import io.hypersistence.utils.spring.domain.Post;
+import io.hypersistence.utils.spring.repository.BaseJpaRepositoryImpl;
+import org.hibernate.boot.spi.MetadataBuilderContributor;
+import org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+
+import java.util.Properties;
+
+/**
+ * @author Vlad Mihalcea
+ */
+@ComponentScan(
+        basePackages = {
+                "io.hypersistence.utils.spring.repo.projection",
+        }
+)
+@EnableJpaRepositories(
+        value = "io.hypersistence.utils.spring.repo.projection",
+        repositoryBaseClass = BaseJpaRepositoryImpl.class
+)
+public class ProjectionSpringDataJPABaseConfiguration extends AbstractSpringDataJPAConfiguration {
+
+    @Override
+    protected String packageToScan() {
+        return Post.class.getPackage().getName();
+    }
+
+    @Override
+    protected void additionalProperties(Properties properties) {
+        properties.put("hibernate.jdbc.batch_size", "100");
+        properties.put("hibernate.order_inserts", "true");
+
+        properties.put(
+                EntityManagerFactoryBuilderImpl.METADATA_BUILDER_CONTRIBUTOR,
+                (MetadataBuilderContributor) metadataBuilder -> metadataBuilder.applyBasicType(
+                        ListArrayType.INSTANCE
+                )
+        );
+    }
+}

hypersistence-utils-hibernate-55/src/test/java/io/hypersistence/utils/spring/repo/projection/ProjectionSpringDataJPABaseTest.java

@@ -0,0 +1,79 @@
+package io.hypersistence.utils.spring.repo.projection;
+
+import io.hypersistence.utils.hibernate.type.util.Configuration;
+import io.hypersistence.utils.spring.domain.Post;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.transaction.support.TransactionCallback;
+import org.springframework.transaction.support.TransactionTemplate;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Vlad Mihalcea
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = ProjectionSpringDataJPABaseConfiguration.class)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+public class ProjectionSpringDataJPABaseTest {
+
+    protected final Logger LOGGER = LoggerFactory.getLogger(getClass());
+
+    @Autowired
+    private TransactionTemplate transactionTemplate;
+
+    @Autowired
+    private PostRepository postRepository;
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Test
+    public void myTest() {
+        // given
+        transactionTemplate.execute((TransactionCallback<Void>) transactionStatus -> {
+            postRepository.persist(
+                    new Post()
+                            .setId(1L)
+                            .setTitle("test title")
+                            .setSlug("slug1")
+            );
+
+            postRepository.persistAndFlush(
+                    new Post()
+                            .setId(2L)
+                            .setTitle("test title")
+                            .setSlug("slug2")
+            );
+
+            return null;
+        });
+
+        // when
+        List<PostRepository.TestProjection> postsSummary = transactionTemplate.execute(transactionStatus ->
+                postRepository.findAllSlugGroupedByTitle()
+        );
+
+        // then
+        PostRepository.TestProjection result = postsSummary.get(0);
+        assertEquals("test title", result.getTitle());
+
+        List<String> expectedSlugs = new ArrayList<>();
+        expectedSlugs.add("slug1");
+        expectedSlugs.add("slug2");
+        assertEquals(expectedSlugs, result.getSlugs());
+    }
+}
+