/*
* Copyright 2012 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
*
* 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 org.springframework.data.repository.core.support;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import org.springframework.data.annotation.Id;
import org.springframework.data.repository.core.EntityInformation;
import org.springframework.data.repository.core.support.AbstractEntityInformation;
import org.springframework.util.Assert;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.ReflectionUtils.FieldCallback;
/**
* {@link EntityInformation} implementation that inspects fields for an annotation and looks up this field's value to
* retrieve the id.
*
* @author Oliver Gierke
*/
public class ReflectionEntityInformation<T, ID extends Serializable> extends AbstractEntityInformation<T, ID> {
private static final Class<Id> DEFAULT_ID_ANNOTATION = Id.class;
private Field field;
/**
* Creates a new {@link ReflectionEntityInformation} inspecting the given domain class for a field carrying the
* {@link Id} annotation.
*
* @param domainClass must not be {@literal null}.
*/
public ReflectionEntityInformation(Class<T> domainClass) {
this(domainClass, DEFAULT_ID_ANNOTATION);
}
/**
* Creates a new {@link ReflectionEntityInformation} inspecting the given domain class for a field carrying the given
* annotation.
*
* @param domainClass must not be {@literal null}.
* @param annotation must not be {@literal null}.
*/
public ReflectionEntityInformation(Class<T> domainClass, final Class<? extends Annotation> annotation) {
super(domainClass);
Assert.notNull(annotation);
ReflectionUtils.doWithFields(domainClass, new FieldCallback() {
public void doWith(Field field) {
if (field.getAnnotation(annotation) != null) {
ReflectionEntityInformation.this.field = field;
return;
}
}
});
Assert.notNull(this.field, String.format("No field annotated with %s found!", annotation.toString()));
ReflectionUtils.makeAccessible(field);
}
/*
* (non-Javadoc)
* @see org.springframework.data.repository.core.EntityInformation#getId(java.lang.Object)
*/
@SuppressWarnings("unchecked")
public ID getId(Object entity) {
return entity == null ? null : (ID) ReflectionUtils.getField(field, entity);
}
/*
* (non-Javadoc)
* @see org.springframework.data.repository.core.EntityInformation#getIdType()
*/
@SuppressWarnings("unchecked")
public Class<ID> getIdType() {
return (Class<ID>) field.getType();
}
}