/*
* Copyright 2013 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.rest.core.util;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.springframework.util.Assert;
import org.springframework.util.MultiValueMap;
/**
* Helper methods to work with {@link Map}s.
*
* @author Oliver Gierke
*/
public interface MapUtils {
/**
* Turns a {@link MultiValueMap} into its {@link Map} equivalent.
*
* @param map must not be {@literal null}.
* @return
*/
public static <K, V> Map<K, Collection<V>> toMap(MultiValueMap<K, V> map) {
Assert.notNull(map, "Given map must not be null!");
Map<K, Collection<V>> result = new LinkedHashMap<K, Collection<V>>(map.size());
for (Entry<K, List<V>> entry : map.entrySet()) {
result.put(entry.getKey(), entry.getValue());
}
return result;
}
}