ValueList.java
/*
* #%L
* wcm.io
* %%
* Copyright (C) 2023 wcm.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
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*/
package io.wcm.siteapi.genericedit.builder.impl.util;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
/**
* Converts a value which is a collection or array to a list of values.
* Otherwise a list with the single value is returned.
* Null values are filtered out.
*/
public final class ValueList {
private final List<Object> values;
private ValueList(@NotNull List<Object> values) {
this.values = values;
}
/**
* @return List of values
*/
public @NotNull List<Object> get() {
return Collections.unmodifiableList(values);
}
/**
* @param rawValue Value which is either a single value, or a collection or array
*/
@SuppressWarnings("unchecked")
public static ValueList from(@Nullable Object rawValue) {
List<Object> values = new ArrayList<>();
if (rawValue != null) {
if (rawValue instanceof Collection) {
Collection<Object> coll = (Collection)rawValue;
coll.stream()
.filter(Objects::nonNull)
.forEach(values::add);
}
else if (rawValue.getClass().isArray()) {
int length = Array.getLength(rawValue);
for (int i = 0; i < length; i++) {
Object item = Array.get(rawValue, i);
if (item != null) {
values.add(item);
}
}
}
else {
values.add(rawValue);
}
}
return new ValueList(values);
}
}