| /* |
| * Copyright (C) 2012 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.reflect; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import java.util.Map; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * A map, each entry of which maps a {@link TypeToken} to an instance of that type. In addition to |
| * implementing {@code Map}, the additional type-safe operations {@link #putInstance} and {@link |
| * #getInstance} are available. |
| * |
| * <p>Generally, implementations don't support {@link #put} and {@link #putAll} because there is no |
| * way to check an object at runtime to be an instance of a {@link TypeToken}. Instead, caller |
| * should use the type safe {@link #putInstance}. |
| * |
| * <p>Also, if caller suppresses unchecked warnings and passes in an {@code Iterable<String>} for |
| * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error. |
| * |
| * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types, |
| * and a primitive type and its corresponding wrapper type may map to different values. |
| * |
| * @param <B> the common supertype that all entries must share; often this is simply {@link Object} |
| * @author Ben Yu |
| * @since 13.0 |
| */ |
| @Beta |
| public interface TypeToInstanceMap<B> extends Map<TypeToken<? extends B>, B> { |
| |
| /** |
| * Returns the value the specified class is mapped to, or {@code null} if no entry for this class |
| * is present. This will only return a value that was bound to this specific class, not a value |
| * that may have been bound to a subtype. |
| * |
| * <p>{@code getInstance(Foo.class)} is equivalent to {@code |
| * getInstance(TypeToken.of(Foo.class))}. |
| */ |
| @NullableDecl |
| <T extends B> T getInstance(Class<T> type); |
| |
| /** |
| * Returns the value the specified type is mapped to, or {@code null} if no entry for this type is |
| * present. This will only return a value that was bound to this specific type, not a value that |
| * may have been bound to a subtype. |
| */ |
| @NullableDecl |
| <T extends B> T getInstance(TypeToken<T> type); |
| |
| /** |
| * Maps the specified class to the specified value. Does <i>not</i> associate this value with any |
| * of the class's supertypes. |
| * |
| * <p>{@code putInstance(Foo.class, foo)} is equivalent to {@code |
| * putInstance(TypeToken.of(Foo.class), foo)}. |
| * |
| * @return the value previously associated with this class (possibly {@code null}), or {@code |
| * null} if there was no previous entry. |
| */ |
| @CanIgnoreReturnValue |
| @NullableDecl |
| <T extends B> T putInstance(Class<T> type, @NullableDecl T value); |
| |
| /** |
| * Maps the specified type to the specified value. Does <i>not</i> associate this value with any |
| * of the type's supertypes. |
| * |
| * @return the value previously associated with this type (possibly {@code null}), or {@code null} |
| * if there was no previous entry. |
| */ |
| @CanIgnoreReturnValue |
| @NullableDecl |
| <T extends B> T putInstance(TypeToken<T> type, @NullableDecl T value); |
| } |