/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.sling.validation.impl.util;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.TypeVariable;
import java.util.Map;
import java.util.Map.Entry;
import javax.annotation.Nonnull;
import org.apache.commons.lang3.reflect.TypeUtils;
import org.apache.sling.validation.spi.Validator;
public class ValidatorTypeUtil {
/** @param validator
* @return the type parametrization value on the {@link Validator} interface */
public static @Nonnull Class<?> getValidatorType(Validator<?> validator) {
// get all type arguments from the current validator class up to the Validator interface
Map<TypeVariable<?>, java.lang.reflect.Type> typeMap = TypeUtils.getTypeArguments(validator.getClass(), Validator.class);
java.lang.reflect.Type type = null;
for (Entry<TypeVariable<?>, java.lang.reflect.Type> entry : typeMap.entrySet()) {
type = entry.getValue();
// check if this is really the type argument defined on the interface {@link Validator}
if (entry.getKey().getGenericDeclaration() instanceof Class<?>) {
Class<?> clazz = (Class<?>) entry.getKey().getGenericDeclaration();
if (clazz.equals(Validator.class)) {
// Java6 doesn't return the class for array types due to this bug: http://bugs.java.com/view_bug.do?bug_id=5041784
if (type instanceof GenericArrayType) {
// as a workaround make a new array class out of the generic component type encapsulated in the generic array type
type = Array.newInstance((Class<?>) ((GenericArrayType) type).getGenericComponentType(), 0).getClass();
}
if (type instanceof Class<?>) {
return (Class<?>) type;
}
// type may also be a parameterized type (e.g. for Collection<String>), this is not allowed!
else {
throw new IllegalArgumentException(
"Validators may not use parameterized types as type parameter. Only simple class types and arrays of class types are allowed.");
}
}
}
}
throw new IllegalArgumentException("Validator '" + validator + "' has not valid type parameter!");
}
}