com.datastax.driver.mapping.DefaultHierarchyScanStrategy Maven / Gradle / Ivy
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/*
* Copyright DataStax, Inc.
*
* 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.datastax.driver.mapping;
import static com.google.common.base.Preconditions.checkNotNull;
import java.util.ArrayList;
import java.util.List;
/**
* The default {@link HierarchyScanStrategy}.
*
* This strategy assumes that there exists a common ancestor for all mapped classes in the
* application, and allows all its descendants (optionally including itself) to be scanned for
* annotations.
*/
public class DefaultHierarchyScanStrategy implements HierarchyScanStrategy {
private final Class highestAncestor;
private final boolean included;
/**
* Creates a new instance with defaults: the common ancestor is {@link Object} excluded, which
* implies that every ancestor of a mapped class, except {@code Object} itself, will be scanned
* for annotations.
*/
public DefaultHierarchyScanStrategy() {
this(Object.class, false);
}
/**
* Creates a new instance with the given highest common ancestor.
*
* @param highestAncestor The highest ancestor class to consider; cannot be {@code null}.
* @param included Whether or not to include the highest ancestor itself.
*/
public DefaultHierarchyScanStrategy(Class highestAncestor, boolean included) {
checkNotNull(highestAncestor);
this.highestAncestor = highestAncestor;
this.included = included;
}
@Override
public List> filterClassHierarchy(Class mappedClass) {
List> classesToScan = new ArrayList>();
Class highestAncestor = this.highestAncestor;
for (Class clazz = mappedClass; clazz != null; clazz = clazz.getSuperclass()) {
if (!clazz.equals(highestAncestor) || included) {
classesToScan.add(clazz);
}
if (clazz.equals(highestAncestor)) {
break;
}
}
return classesToScan;
}
}