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The common module with base models and useful utils.
/*
* Copyright (c) 2020 https://rxmicro.io
*
* 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 io.rxmicro.common.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import static java.util.Map.entry;
import static java.util.stream.Collectors.toList;
import static java.util.stream.Collectors.toSet;
/**
* @author nedis
* @link https://rxmicro.io
* @since 0.1
*/
public final class ExCollections {
public static final String[] EMPTY_STRING_ARRAY = new String[0];
@SuppressWarnings("rawtypes")
private static final Set> UNMODIFIABLE_MAP_CLASSES = Set.of(
Collections.unmodifiableMap(Map.of()).getClass(), // java.util.Collections.UnmodifiableMap
Map.of().getClass(), // java.util.ImmutableCollections.MapN
Map.of(1, 1).getClass() // java.util.ImmutableCollections.Map1
);
@SuppressWarnings("rawtypes")
private static final Set> UNMODIFIABLE_SET_CLASSES = Set.of(
Collections.unmodifiableSet(Set.of()).getClass(), // java.util.Collections.UnmodifiableSet
Set.of().getClass(), // java.util.ImmutableCollections.SetN
Set.of(1).getClass() // java.util.ImmutableCollections.Set12
);
@SuppressWarnings("rawtypes")
private static final Set> UNMODIFIABLE_LIST_CLASSES = Set.of(
Collections.unmodifiableList(List.of()).getClass(), // java.util.Collections.UnmodifiableList
List.of().getClass(), // java.util.ImmutableCollections.ListN
List.of(1).getClass() // java.util.ImmutableCollections.List12
);
public static boolean isUnmodifiableList(final Object object) {
return object != null &&
UNMODIFIABLE_LIST_CLASSES.contains(object.getClass());
}
@SuppressWarnings("Java9CollectionFactory")
public static List unmodifiableList(final Collection collection) {
if (collection.isEmpty()) {
return List.of();
} else if (UNMODIFIABLE_LIST_CLASSES.contains(collection.getClass())) {
return (List) collection;
} else if (collection.size() == 1) {
return List.of(collection.iterator().next());
} else if (collection instanceof List) {
return Collections.unmodifiableList((List) collection);
} else {
return Collections.unmodifiableList(new ArrayList<>(collection));
}
}
public static boolean isUnmodifiableMap(final Object object) {
return object != null &&
UNMODIFIABLE_MAP_CLASSES.contains(object.getClass());
}
public static Map unmodifiableMap(final Map map) {
return unmodifiableOrderedMap(map);
}
public static Map unmodifiableOrderedMap(final Map map) {
if (map.isEmpty()) {
return Map.of();
} else if (UNMODIFIABLE_MAP_CLASSES.contains(map.getClass())) {
return map;
} else if (map.size() == 1) {
final Map.Entry entry = map.entrySet().iterator().next();
return Map.of(entry.getKey(), entry.getValue());
} else {
return Collections.unmodifiableMap(map);
}
}
public static Set unmodifiableOrderedSet(final Collection collection) {
if (collection.isEmpty()) {
return Set.of();
} else if (UNMODIFIABLE_SET_CLASSES.contains(collection.getClass())) {
return (Set) collection;
} else if (collection.size() == 1) {
return Set.of(collection.iterator().next());
} else if (collection instanceof Set) {
return Collections.unmodifiableSet((Set) collection);
} else {
return Collections.unmodifiableSet(new LinkedHashSet<>(collection));
}
}
@SafeVarargs
public static Set unmodifiableOrderedSet(final E... elements) {
return unmodifiableOrderedSet(Arrays.asList(elements));
}
@SafeVarargs
public static Set join(final Set... items) {
return Arrays.stream(items).flatMap(Collection::stream).collect(toSet());
}
@SafeVarargs
public static List join(final List... items) {
return Arrays.stream(items).flatMap(Collection::stream).collect(toList());
}
public static Map orderedMap(final K k1, final V v1) {
return orderedMapFromEntries(
entry(k1, v1)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5,
final K k6, final V v6) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5),
entry(k6, v6)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5,
final K k6, final V v6,
final K k7, final V v7) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5),
entry(k6, v6),
entry(k7, v7)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5,
final K k6, final V v6,
final K k7, final V v7,
final K k8, final V v8) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5),
entry(k6, v6),
entry(k7, v7),
entry(k8, v8)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5,
final K k6, final V v6,
final K k7, final V v7,
final K k8, final V v8,
final K k9, final V v9) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5),
entry(k6, v6),
entry(k7, v7),
entry(k8, v8),
entry(k9, v9)
);
}
public static Map orderedMap(final K k1, final V v1,
final K k2, final V v2,
final K k3, final V v3,
final K k4, final V v4,
final K k5, final V v5,
final K k6, final V v6,
final K k7, final V v7,
final K k8, final V v8,
final K k9, final V v9,
final K k10, final V v10) {
return orderedMapFromEntries(
entry(k1, v1),
entry(k2, v2),
entry(k3, v3),
entry(k4, v4),
entry(k5, v5),
entry(k6, v6),
entry(k7, v7),
entry(k8, v8),
entry(k9, v9),
entry(k10, v10)
);
}
@SafeVarargs
@SuppressWarnings("varargs")
public static Map orderedMapFromEntries(Map.Entry... entries) {
final Map map = new LinkedHashMap<>();
for (final Map.Entry entry : entries) {
map.put(entry.getKey(), entry.getValue());
}
return unmodifiableMap(map);
}
private ExCollections() {
}
}
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