io.grpc.okhttp.internal.Util Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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.
*/
/*
* Forked from OkHttp 2.5.0
*/
package io.grpc.okhttp.internal;
import java.lang.reflect.Array;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/** Junk drawer of utility methods. */
public final class Util {
public static final String[] EMPTY_STRING_ARRAY = new String[0];
/** A cheap and type-safe constant for the UTF-8 Charset. */
public static final Charset UTF_8 = Charset.forName("UTF-8");
private Util() {
}
/** Returns true if two possibly-null objects are equal. */
public static boolean equal(Object a, Object b) {
return a == b || (a != null && a.equals(b));
}
/** Returns an immutable list containing {@code elements}. */
public static List immutableList(T[] elements) {
return Collections.unmodifiableList(Arrays.asList(elements.clone()));
}
/**
* Returns an array containing containing only elements found in {@code first} and also in
* {@code second}. The returned elements are in the same order as in {@code first}.
*/
@SuppressWarnings("unchecked")
public static T[] intersect(Class arrayType, T[] first, T[] second) {
List result = intersect(first, second);
return result.toArray((T[]) Array.newInstance(arrayType, result.size()));
}
/**
* Returns a list containing containing only elements found in {@code first} and also in
* {@code second}. The returned elements are in the same order as in {@code first}.
*/
private static List intersect(T[] first, T[] second) {
List result = new ArrayList<>();
for (T a : first) {
for (T b : second) {
if (a.equals(b)) {
result.add(b);
break;
}
}
}
return result;
}
}