| /* |
| * 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.common.collect.ForwardingMap; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import com.google.errorprone.annotations.DoNotCall; |
| import java.util.Map; |
| |
| /** |
| * A type-to-instance map backed by an {@link ImmutableMap}. See also {@link |
| * MutableTypeToInstanceMap}. |
| * |
| * @author Ben Yu |
| * @since 13.0 |
| */ |
| @Beta |
| public final class ImmutableTypeToInstanceMap<B> extends ForwardingMap<TypeToken<? extends B>, B> |
| implements TypeToInstanceMap<B> { |
| |
| /** Returns an empty type to instance map. */ |
| public static <B> ImmutableTypeToInstanceMap<B> of() { |
| return new ImmutableTypeToInstanceMap<B>(ImmutableMap.<TypeToken<? extends B>, B>of()); |
| } |
| |
| /** Returns a new builder. */ |
| public static <B> Builder<B> builder() { |
| return new Builder<B>(); |
| } |
| |
| /** |
| * A builder for creating immutable type-to-instance maps. Example: |
| * |
| * <pre>{@code |
| * static final ImmutableTypeToInstanceMap<Handler<?>> HANDLERS = |
| * ImmutableTypeToInstanceMap.<Handler<?>>builder() |
| * .put(new TypeToken<Handler<Foo>>() {}, new FooHandler()) |
| * .put(new TypeToken<Handler<Bar>>() {}, new SubBarHandler()) |
| * .build(); |
| * }</pre> |
| * |
| * <p>After invoking {@link #build()} it is still possible to add more entries and build again. |
| * Thus each map generated by this builder will be a superset of any map generated before it. |
| * |
| * @since 13.0 |
| */ |
| @Beta |
| public static final class Builder<B> { |
| private final ImmutableMap.Builder<TypeToken<? extends B>, B> mapBuilder = |
| ImmutableMap.builder(); |
| |
| private Builder() {} |
| |
| /** |
| * Associates {@code key} with {@code value} in the built map. Duplicate keys are not allowed, |
| * and will cause {@link #build} to fail. |
| */ |
| @CanIgnoreReturnValue |
| public <T extends B> Builder<B> put(Class<T> key, T value) { |
| mapBuilder.put(TypeToken.of(key), value); |
| return this; |
| } |
| |
| /** |
| * Associates {@code key} with {@code value} in the built map. Duplicate keys are not allowed, |
| * and will cause {@link #build} to fail. |
| */ |
| @CanIgnoreReturnValue |
| public <T extends B> Builder<B> put(TypeToken<T> key, T value) { |
| mapBuilder.put(key.rejectTypeVariables(), value); |
| return this; |
| } |
| |
| /** |
| * Returns a new immutable type-to-instance map containing the entries provided to this builder. |
| * |
| * @throws IllegalArgumentException if duplicate keys were added |
| */ |
| public ImmutableTypeToInstanceMap<B> build() { |
| return new ImmutableTypeToInstanceMap<B>(mapBuilder.build()); |
| } |
| } |
| |
| private final ImmutableMap<TypeToken<? extends B>, B> delegate; |
| |
| private ImmutableTypeToInstanceMap(ImmutableMap<TypeToken<? extends B>, B> delegate) { |
| this.delegate = delegate; |
| } |
| |
| @Override |
| public <T extends B> T getInstance(TypeToken<T> type) { |
| return trustedGet(type.rejectTypeVariables()); |
| } |
| |
| @Override |
| public <T extends B> T getInstance(Class<T> type) { |
| return trustedGet(TypeToken.of(type)); |
| } |
| |
| /** |
| * Guaranteed to throw an exception and leave the map unmodified. |
| * |
| * @deprecated unsupported operation |
| * @throws UnsupportedOperationException always |
| */ |
| @CanIgnoreReturnValue |
| @Deprecated |
| @Override |
| @DoNotCall("Always throws UnsupportedOperationException") |
| public <T extends B> T putInstance(TypeToken<T> type, T value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Guaranteed to throw an exception and leave the map unmodified. |
| * |
| * @deprecated unsupported operation |
| * @throws UnsupportedOperationException always |
| */ |
| @CanIgnoreReturnValue |
| @Deprecated |
| @Override |
| @DoNotCall("Always throws UnsupportedOperationException") |
| public <T extends B> T putInstance(Class<T> type, T value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Guaranteed to throw an exception and leave the map unmodified. |
| * |
| * @deprecated unsupported operation |
| * @throws UnsupportedOperationException always |
| */ |
| @CanIgnoreReturnValue |
| @Deprecated |
| @Override |
| @DoNotCall("Always throws UnsupportedOperationException") |
| public B put(TypeToken<? extends B> key, B value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * Guaranteed to throw an exception and leave the map unmodified. |
| * |
| * @deprecated unsupported operation |
| * @throws UnsupportedOperationException always |
| */ |
| @Deprecated |
| @Override |
| @DoNotCall("Always throws UnsupportedOperationException") |
| public void putAll(Map<? extends TypeToken<? extends B>, ? extends B> map) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| protected Map<TypeToken<? extends B>, B> delegate() { |
| return delegate; |
| } |
| |
| @SuppressWarnings("unchecked") // value could not get in if not a T |
| private <T extends B> T trustedGet(TypeToken<T> type) { |
| return (T) delegate.get(type); |
| } |
| } |