/*
* Copyright (c) 2009-2010 Clark & Parsia, LLC. <http://www.clarkparsia.com>
*
* 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.clarkparsia.empire.annotation;
import com.clarkparsia.empire.util.BeanReflectUtil;
import static com.clarkparsia.empire.util.BeanReflectUtil.getAnnotatedFields;
import static com.clarkparsia.empire.util.BeanReflectUtil.getAnnotatedGetters;
import com.clarkparsia.empire.SupportsRdfId;
import com.clarkparsia.empire.EmpireException;
import com.clarkparsia.empire.EmpireOptions;
import javax.persistence.Entity;
import javax.persistence.OneToMany;
import javax.persistence.ManyToMany;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.HashSet;
/**
* <p>Utility class for checking that a class has the required annotations on it and that it's annotations are used
* correctly. For example, OneToMany annotations should be used on a field or method that returns a Collection,
* and all classes need an {@link RdfsClass} annotation.</p>
*
* @author Michael Grove
* @author uoccou
* @since 0.6.5
* @version 0.7
*/
public final class AnnotationChecker {
/**
* No instances
*/
private AnnotationChecker() {
}
/**
* Return whether or not the class has the minimum set of annotations required for use by Empire and that all
* other annotations, such as OneToMany, are used correctly.
* @param theClass the class to validate.
* @throws com.clarkparsia.empire.EmpireException if
*/
public static void assertValid(final Class theClass) throws EmpireException {
if (!isEmpireCompatible(theClass)) {
throw new EmpireException("Missing a required annotation (Entity & RdfsClass) or does not implement SupportsRdfId");
}
Collection<AccessibleObject> aAccessors = new HashSet<AccessibleObject>();
aAccessors.addAll(getAnnotatedFields(theClass));
aAccessors.addAll(getAnnotatedGetters(theClass, true));
for (AccessibleObject aObj : aAccessors) {
if (aObj.getAnnotation(OneToMany.class) != null ||
aObj.getAnnotation(ManyToMany.class) != null) {
Class aType = aObj instanceof Field
? ((Field)aObj).getType()
: ((Method)aObj).getReturnType();
if (!Collection.class.isAssignableFrom(aType)) {
throw new EmpireException("Using OneToMany or ManyToMany annotation on a non-collection field : " + theClass + "." + aType);
}
}
}
}
/**
* Equivalent to {@link #assertValid} but returns the validity as a boolean rather than throwing an exception.
* @param theClass the class to validate
* @return true if the class is valid, false otherwise
*/
public static boolean isValid(final Class theClass) {
try {
assertValid(theClass);
return true;
}
catch (EmpireException e) {
return false;
}
}
/**
* For OWL based restrictions, make sure the values on the java bean respect the annotations placed on the
* fields.
* @param theObj the object to validate
* @throws Exception thrown if the object is not in a valid state wrt to its data.
*/
public static void validateState(final Object theObj) throws Exception {
// TODO: implement me
}
/**
* Return whether or not the given class instances is compatible with Empire, in that it has all the required
* annotations, and can have an rdf:ID.
* @param theClass the class to check
* @return true if its Empire compatible, false otherwise.
*/
private static boolean isEmpireCompatible(final Class theClass) {
return (!EmpireOptions.ENFORCE_ENTITY_ANNOTATION || BeanReflectUtil.hasAnnotation(theClass, Entity.class)) &&
BeanReflectUtil.hasAnnotation(theClass, RdfsClass.class) &&
SupportsRdfId.class.isAssignableFrom(theClass);
}
}