Common.java
/*
* Copyright 2018 The Android Open Source Project
*
* 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 androidx.car.cluster.navigation;
import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP_PREFIX;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
/**
* Helper methods
*
* @hide
*/
@RestrictTo(LIBRARY_GROUP_PREFIX)
final class Common {
/**
* This is a utility class
*/
private Common() {
}
/**
* Returns the given string, or an empty string if the value is null.
*/
@NonNull
public static String nonNullOrEmpty(@Nullable String value) {
return value != null ? value : "";
}
/**
* Returns an immutable view of the given list, or an empty one if the list is null, or if any
* of its elements is null.
*/
@NonNull
public static <T> List<T> immutableOrEmpty(@Nullable List<T> list) {
if (list == null || list.stream().anyMatch(Objects::isNull)) {
return Collections.emptyList();
}
return Collections.unmodifiableList(list);
}
}