| /* |
| * 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 com.google.common.base; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.annotations.GwtIncompatible; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * 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. |
| */ |
| @SuppressWarnings("unchecked") |
| @NullableDecl |
| public static <T> T defaultValue(Class<T> 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; |
| } |
| } |
| } |