DATAKV-310 - Guard repository implementations against null values.

SimpleKeyValueRepository and QuerydslKeyValueRepository now reject null arguments as per their interface contract.

Original Pull Request: #50

src/main/java/org/springframework/data/keyvalue/repository/support/QuerydslKeyValueRepository.java

@@ -96,6 +96,8 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	@Override
 	public Optional<T> findOne(Predicate predicate) {
 
+		Assert.notNull(predicate, "Predicate must not be null");
+
 		try {
 			return Optional.ofNullable(prepareQuery(predicate).fetchOne());
 		} catch (NonUniqueResultException o_O) {
@@ -109,6 +111,9 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	 */
 	@Override
 	public Iterable<T> findAll(Predicate predicate) {
+
+		Assert.notNull(predicate, "Predicate must not be null");
+
 		return prepareQuery(predicate).fetchResults().getResults();
 	}
 
@@ -119,6 +124,9 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	@Override
 	public Iterable<T> findAll(Predicate predicate, OrderSpecifier<?>... orders) {
 
+		Assert.notNull(predicate, "Predicate must not be null");
+		Assert.notNull(orders, "OrderSpecifiers must not be null");
+
 		AbstractCollQuery<T, ?> query = prepareQuery(predicate);
 		query.orderBy(orders);
 
@@ -131,6 +139,10 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	 */
 	@Override
 	public Iterable<T> findAll(Predicate predicate, Sort sort) {
+
+		Assert.notNull(predicate, "Predicate must not be null");
+		Assert.notNull(sort, "Sort must not be null");
+
 		return findAll(predicate, toOrderSpecifier(sort, builder));
 	}
 
@@ -141,6 +153,9 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	@Override
 	public Page<T> findAll(Predicate predicate, Pageable pageable) {
 
+		Assert.notNull(predicate, "Predicate must not be null");
+		Assert.notNull(pageable, "Pageable must not be null");
+
 		AbstractCollQuery<T, ?> query = prepareQuery(predicate);
 
 		if (pageable.isPaged() || pageable.getSort().isSorted()) {
@@ -163,6 +178,8 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	@Override
 	public Iterable<T> findAll(OrderSpecifier<?>... orders) {
 
+		Assert.notNull(orders, "OrderSpecifiers must not be null");
+
 		if (ObjectUtils.isEmpty(orders)) {
 			return findAll();
 		}
@@ -179,6 +196,9 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	 */
 	@Override
 	public long count(Predicate predicate) {
+
+		Assert.notNull(predicate, "Predicate must not be null");
+
 		return prepareQuery(predicate).fetchCount();
 	}
 
@@ -188,6 +208,9 @@ public class QuerydslKeyValueRepository<T, ID> extends SimpleKeyValueRepository<
 	 */
 	@Override
 	public boolean exists(Predicate predicate) {
+
+		Assert.notNull(predicate, "Predicate must not be null");
+
 		return count(predicate) > 0;
 	}
 

src/main/java/org/springframework/data/keyvalue/repository/support/SimpleKeyValueRepository.java

@@ -64,6 +64,9 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	 */
 	@Override
 	public Iterable<T> findAll(Sort sort) {
+
+		Assert.notNull(sort, "Sort must not be null!");
+
 		return operations.findAll(sort, entityInformation.getJavaType());
 	}
 
@@ -111,6 +114,8 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	@Override
 	public <S extends T> Iterable<S> saveAll(Iterable<S> entities) {
 
+		Assert.notNull(entities, "The given Iterable of entities must not be null");
+
 		List<S> saved = new ArrayList<>();
 
 		for (S entity : entities) {
@@ -126,6 +131,9 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	 */
 	@Override
 	public Optional<T> findById(ID id) {
+
+		Assert.notNull(id, "The given id must not be null");
+
 		return operations.findById(id, entityInformation.getJavaType());
 	}
 
@@ -154,6 +162,8 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	@Override
 	public Iterable<T> findAllById(Iterable<ID> ids) {
 
+		Assert.notNull(ids, "The given Iterable of id's must not be null");
+
 		List<T> result = new ArrayList<>();
 
 		ids.forEach(id -> findById(id).ifPresent(result::add));
@@ -176,6 +186,9 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	 */
 	@Override
 	public void deleteById(ID id) {
+
+		Assert.notNull(id, "The given id must not be null");
+
 		operations.delete(id, entityInformation.getJavaType());
 	}
 
@@ -185,6 +198,9 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	 */
 	@Override
 	public void delete(T entity) {
+
+		Assert.notNull(entity, "The given entity must not be null");
+
 		deleteById(entityInformation.getRequiredId(entity));
 	}
 
@@ -194,6 +210,9 @@ public class SimpleKeyValueRepository<T, ID> implements KeyValueRepository<T, ID
 	 */
 	@Override
 	public void deleteAll(Iterable<? extends T> entities) {
+
+		Assert.notNull(entities, "The given Iterable of entities must not be null");
+
 		entities.forEach(this::delete);
 	}