org.testifyproject.guava.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 org.testifyproject.guava.common.base;
import static org.testifyproject.guava.common.base.Preconditions.checkNotNull;
import org.testifyproject.guava.common.annotations.GwtIncompatible;
import javax.annotation.Nullable;
/**
* This class provides default values for all Java types, as defined by the JLS.
*
* @author Ben Yu
* @since 1.0
*/
@GwtIncompatible
public final class Defaults {
private Defaults() {}
private static final Double DOUBLE_DEFAULT = Double.valueOf(0d);
private static final Float FLOAT_DEFAULT = Float.valueOf(0f);
/**
* 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}, {@code null} is returned.
*/
@Nullable
@SuppressWarnings("unchecked")
public static T defaultValue(Class type) {
checkNotNull(type);
if (type == boolean.class) {
return (T) Boolean.FALSE;
} else if (type == char.class) {
return (T) Character.valueOf('\0');
} else if (type == byte.class) {
return (T) Byte.valueOf((byte) 0);
} else if (type == short.class) {
return (T) Short.valueOf((short) 0);
} else if (type == int.class) {
return (T) Integer.valueOf(0);
} else if (type == long.class) {
return (T) Long.valueOf(0L);
} else if (type == float.class) {
return (T) FLOAT_DEFAULT;
} else if (type == double.class) {
return (T) DOUBLE_DEFAULT;
} else {
return null;
}
}
}