/*
* Copyright (C) 2012-2015 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 com.datastax.driver.mapping.annotations.UDT;
import com.google.common.collect.Sets;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Utility methods to determine which CQL type we expect for a given Java field type.
*/
class TypeMappings {
private static boolean mapsToCollection(Class<?> klass) {
return mapsToList(klass) || mapsToSet(klass) || mapsToMap(klass);
}
private static boolean mapsToList(Class<?> klass) {
return List.class.equals(klass);
}
private static boolean mapsToSet(Class<?> klass) {
return Set.class.equals(klass);
}
private static boolean mapsToMap(Class<?> klass) {
return Map.class.equals(klass);
}
static boolean isMappedUDT(Class<?> klass) {
return klass.isAnnotationPresent(UDT.class);
}
/**
* Traverses the type of a Java field or parameter to find classes annotated with @UDT.
* This will recurse into nested collections, e.g. List<Set<TheMappedUDT>>
*/
static Set<Class<?>> findUDTs(Type type) {
Set<Class<?>> udts = findUDTs(type, null);
return (udts == null)
? Collections.<Class<?>>emptySet()
: udts;
}
private static Set<Class<?>> findUDTs(Type type, Set<Class<?>> udts) {
if (type instanceof ParameterizedType) {
ParameterizedType pt = (ParameterizedType) type;
Type raw = pt.getRawType();
if ((raw instanceof Class)) {
Class<?> klass = (Class<?>) raw;
if (mapsToCollection(klass)) {
Type[] childTypes = pt.getActualTypeArguments();
udts = findUDTs(childTypes[0], udts);
if (mapsToMap(klass))
udts = findUDTs(childTypes[1], udts);
}
}
} else if (type instanceof Class) {
Class<?> klass = (Class<?>) type;
if (isMappedUDT(klass)) {
if (udts == null)
udts = Sets.newHashSet();
udts.add(klass);
}
}
return udts;
}
}