DATAJDBC-378 - Proper handling of null and empty collections in JdbcAggregateTemplate.

Original Pull Request: #155

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateTemplate.java

@@ -152,6 +152,9 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	 */
 	@Override
 	public long count(Class<?> domainType) {
+
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		return accessStrategy.count(domainType);
 	}
 
@@ -162,6 +165,9 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	@Override
 	public <T> T findById(Object id, Class<T> domainType) {
 
+		Assert.notNull(id, "Id must not be null");
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		T entity = accessStrategy.findById(id, domainType);
 		if (entity != null) {
 			publishAfterLoad(id, entity);
@@ -175,6 +181,10 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	 */
 	@Override
 	public <T> boolean existsById(Object id, Class<T> domainType) {
+
+		Assert.notNull(id, "Id must not be null");
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		return accessStrategy.existsById(id, domainType);
 	}
 
@@ -185,6 +195,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	@Override
 	public <T> Iterable<T> findAll(Class<T> domainType) {
 
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		Iterable<T> all = accessStrategy.findAll(domainType);
 		publishAfterLoad(all);
 		return all;
@@ -197,6 +209,9 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	@Override
 	public <T> Iterable<T> findAllById(Iterable<?> ids, Class<T> domainType) {
 
+		Assert.notNull(ids, "Ids must not be null");
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		Iterable<T> allById = accessStrategy.findAllById(ids, domainType);
 		publishAfterLoad(allById);
 		return allById;
@@ -209,6 +224,9 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	@Override
 	public <S> void delete(S aggregateRoot, Class<S> domainType) {
 
+		Assert.notNull(aggregateRoot, "Aggregate root must not be null");
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		IdentifierAccessor identifierAccessor = context.getRequiredPersistentEntity(domainType)
 				.getIdentifierAccessor(aggregateRoot);
 
@@ -221,6 +239,10 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	 */
 	@Override
 	public <S> void deleteById(Object id, Class<S> domainType) {
+
+		Assert.notNull(id, "Id must not be null");
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		deleteTree(id, null, domainType);
 	}
 
@@ -231,6 +253,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 	@Override
 	public void deleteAll(Class<?> domainType) {
 
+		Assert.notNull(domainType, "Domain type must not be null");
+
 		AggregateChange<?> change = createDeletingChange(domainType);
 		change.executeWith(interpreter, context, converter);
 	}

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/DefaultDataAccessStrategy.java

@@ -18,6 +18,7 @@ package org.springframework.data.jdbc.core.convert;
 import java.sql.JDBCType;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -241,6 +242,10 @@ public class DefaultDataAccessStrategy implements DataAccessStrategy {
 	@SuppressWarnings("unchecked")
 	public <T> Iterable<T> findAllById(Iterable<?> ids, Class<T> domainType) {
 
+		if (!ids.iterator().hasNext()) {
+			return Collections.emptyList();
+		}
+
 		RelationalPersistentProperty idProperty = getRequiredPersistentEntity(domainType).getRequiredIdProperty();
 		MapSqlParameterSource parameterSource = new MapSqlParameterSource();
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/JdbcAggregateTemplateIntegrationTests.java

@@ -35,7 +35,6 @@ import org.junit.Assume;
 import org.junit.ClassRule;
 import org.junit.Rule;
 import org.junit.Test;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.context.annotation.Bean;
@@ -597,6 +596,24 @@ public class JdbcAggregateTemplateIntegrationTests {
 		});
 	}
 
+	@Test // DATAJDBC-378
+	public void findAllByIdMustNotAcceptNullArgumentForType() {
+
+		assertThatThrownBy(() -> template.findAllById(singleton(23L), null)).isInstanceOf(IllegalArgumentException.class);
+	}
+
+	@Test // DATAJDBC-378
+	public void findAllByIdMustNotAcceptNullArgumentForIds() {
+
+		assertThatThrownBy(() -> template.findAllById(null, LegoSet.class)).isInstanceOf(IllegalArgumentException.class);
+	}
+
+	@Test // DATAJDBC-378
+	public void findAllByIdWithEmpthListMustReturnEmptyResult() {
+
+		assertThat(template.findAllById(emptyList(), LegoSet.class)).isEmpty();
+	}
+
 	private static NoIdMapChain4 createNoIdMapTree() {
 
 		NoIdMapChain4 chain4 = new NoIdMapChain4();