/*
* Copyright 2014 - 2017 Blazebit.
*
* 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
*
* http://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 com.blazebit.persistence.view.filter;
import com.blazebit.persistence.view.AttributeFilter;
import com.blazebit.persistence.view.AttributeFilterProvider;
/**
* A placeholder for a filter implementation that implements a is null and is not null filter.
* This placeholder can be used in a {@link AttributeFilter} annotation.
*
* A null filter accepts an object. The {@linkplain Object#toString()} representation of that object will be parsed to a boolean
* if the object is not instance of {@linkplain Boolean}.
* If the resulting boolean is true, the filter will apply an is null restriction, otherwise an is not null restriction.
*
* @author Christian Beikov
* @since 1.0.0
*/
public abstract class NullFilter extends AttributeFilterProvider {
}