/*
* Copyright 2000-2015 JetBrains s.r.o.
*
* 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.intellij.util;
import com.intellij.openapi.util.Condition;
import com.intellij.util.containers.Convertor;
import org.jetbrains.annotations.Contract;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
/**
* @author peter
*/
public class ObjectUtil {
private ObjectUtil() {
}
public static final Object NULL = new Object();
@NotNull
public static <T> T assertNotNull(@Nullable T t) {
return notNull(t);
}
public static <T> void assertAllElementsNotNull(@NotNull T[] array) {
for (int i = 0; i < array.length; i++) {
T t = array[i];
if (t == null) {
throw new NullPointerException("Element [" + i + "] is null");
}
}
}
@Contract("null, null -> null")
public static <T> T chooseNotNull(@Nullable T t1, @Nullable T t2) {
return t1 == null? t2 : t1;
}
@Contract("null,null->null")
public static <T> T coalesce(@Nullable T t1, @Nullable T t2) {
return t1 != null ? t1 : t2;
}
@Contract("null,null,null->null")
public static <T> T coalesce(@Nullable T t1, @Nullable T t2, @Nullable T t3) {
return t1 != null ? t1 : t2 != null ? t2 : t3;
}
@Nullable
public static <T> T coalesce(@Nullable Iterable<T> o) {
if (o == null) return null;
for (T t : o) {
if (t != null) return t;
}
return null;
}
@NotNull
public static <T> T notNull(@Nullable T value) {
//noinspection ConstantConditions
return notNull(value, value);
}
@NotNull
public static <T> T notNull(@Nullable T value, @NotNull T defaultValue) {
return value == null ? defaultValue : value;
}
@Nullable
public static <T> T tryCast(@Nullable Object obj, @NotNull Class<T> clazz) {
if (clazz.isInstance(obj)) {
return clazz.cast(obj);
}
return null;
}
@Nullable
public static <T, S> S doIfCast(@Nullable Object obj, @NotNull Class<T> clazz, final Convertor<T, S> convertor) {
if (clazz.isInstance(obj)) {
//noinspection unchecked
return convertor.convert((T)obj);
}
return null;
}
@Nullable
public static <T> T nullizeByCondition(@Nullable final T obj, @NotNull final Condition<T> condition) {
if (condition.value(obj)) {
return null;
}
return obj;
}
}