com.netflix.spinnaker.kork.test.MapUtils Maven / Gradle / Ivy
/*
* Copyright 2019 Netflix, 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.netflix.spinnaker.kork.test;
import java.util.Collection;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nonnull;
/** Provides a standard library of helper functions for Map types. */
public class MapUtils {
/**
* Returns a new map that is the result of deeply merging original and overrides.
*
* Each key in original is merged with the corresponding key in overrides as follows: - an
* explicitly null entry in overrides removes a key in original - a map in original is merged with
* a map from overrides (via call to merge) - a non map in overrides results in an
* IllegalStateException - a collection in original is replaced with a collection in overrides - a
* non collection in overrides results in an IllegalStateException - the value is taken from
* overrides
*
*
Each remaining key in overrides is then added to the resulting map.
*
* @param original the original Map
* @param override the Map to override/merge into original
* @return a new Map containing the merge of original and overrides (never null)
* @throws IllegalStateException if incompatible types exist between original and overrides
*/
@Nonnull
public static Map merge(
@Nonnull Map original, @Nonnull Map override) {
final Set remainingKeys = new LinkedHashSet<>(override.keySet());
final Map result = new LinkedHashMap<>();
for (Map.Entry entry : original.entrySet()) {
final String key = entry.getKey();
result.put(key, entry.getValue());
if (override.containsKey(key)) {
final Object value = override.get(key);
if (value == null) {
result.remove(key);
} else {
result.merge(key, value, MapUtils::mergeObject);
}
}
remainingKeys.remove(key);
}
for (String newKey : remainingKeys) {
result.put(newKey, override.get(newKey));
}
return result;
}
private static Object mergeObject(Object original, Object override) {
if (original instanceof Map) {
if (!(override instanceof Map)) {
throw new IllegalMergeTypeException(
"Attempt to merge Map with " + override.getClass().getSimpleName());
}
return merge(toMap(original), toMap(override));
} else if (original instanceof Collection) {
if (!(override instanceof Collection)) {
throw new IllegalMergeTypeException(
"Attempt to replace Collection with " + override.getClass().getSimpleName());
}
}
return override;
}
@SuppressWarnings("unchecked")
private static Map toMap(Object o) {
return (Map) o;
}
public static class IllegalMergeTypeException extends KorkTestException {
public IllegalMergeTypeException(String message) {
super(message);
}
}
}