jersey.repackaged.com.google.common.base.Defaults Maven / Gradle / Ivy
/*
* Copyright (C) 2007 The Guava Authors
*
* 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 jersey.repackaged.com.google.common.base;
import static jersey.repackaged.com.google.common.base.Preconditions.checkNotNull;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* This class provides default values for all Java types, as defined by the JLS.
*
* @author Ben Yu
* @since 1.0
*/
public final class Defaults {
private Defaults() {}
private static final Map, Object> DEFAULTS;
static {
Map, Object> map = new HashMap, Object>();
put(map, boolean.class, false);
put(map, char.class, '\0');
put(map, byte.class, (byte) 0);
put(map, short.class, (short) 0);
put(map, int.class, 0);
put(map, long.class, 0L);
put(map, float.class, 0f);
put(map, double.class, 0d);
DEFAULTS = Collections.unmodifiableMap(map);
}
private static void put(Map, Object> map, Class type, T value) {
map.put(type, value);
}
/**
* Returns the default value of {@code type} as defined by JLS --- {@code 0} for numbers, {@code
* false} for {@code boolean} and {@code '\0'} for {@code char}. For non-primitive types and
* {@code void}, null is returned.
*/
@SuppressWarnings("unchecked")
public static T defaultValue(Class type) {
return (T) DEFAULTS.get(checkNotNull(type));
}
}