/*
* Copyright 2014-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.data.projection;
import org.springframework.lang.Nullable;
A factory to create projecting instances for other objects usually used to allow easy creation of representation
projections to define which properties of a domain objects shall be exported in which way.
Author: Oliver Gierke Since: 1.10
/**
* A factory to create projecting instances for other objects usually used to allow easy creation of representation
* projections to define which properties of a domain objects shall be exported in which way.
*
* @author Oliver Gierke
* @since 1.10
*/
public interface ProjectionFactory {
Creates a projection of the given type for the given source object. The individual mapping strategy is defined by
the implementations.
Params: - projectionType – the type to create, must not be null.
- source – the object to create a projection for, must not be null.
Returns:
/**
* Creates a projection of the given type for the given source object. The individual mapping strategy is defined by
* the implementations.
*
* @param projectionType the type to create, must not be {@literal null}.
* @param source the object to create a projection for, must not be {@literal null}.
* @return
*/
<T> T createProjection(Class<T> projectionType, Object source);
Creates a projection to the given type for the given nullable source.
Params: - projectionType – must not be null.
- source – can be null.
Returns:
/**
* Creates a projection to the given type for the given nullable source.
*
* @param projectionType must not be {@literal null}.
* @param source can be {@literal null}.
* @return
*/
@Nullable
default <T> T createNullableProjection(Class<T> projectionType, @Nullable Object source) {
return source == null ? null : createProjection(projectionType, source);
}
Creates a projection instance for the given type.
Params: - projectionType – the type to create, must not be null.
Returns:
/**
* Creates a projection instance for the given type.
*
* @param projectionType the type to create, must not be {@literal null}.
* @return
*/
<T> T createProjection(Class<T> projectionType);
Returns the ProjectionInformation
for the given projection type. Params: - projectionType – must not be null.
Returns: Since: 1.12
/**
* Returns the {@link ProjectionInformation} for the given projection type.
*
* @param projectionType must not be {@literal null}.
* @return
* @since 1.12
*/
ProjectionInformation getProjectionInformation(Class<?> projectionType);
}