Java example source code file (ClassToInstanceMap.java)

This example Java source code file (ClassToInstanceMap.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

annotation, canignorereturnvalue, classtoinstancemap, consider, gwtcompatible, nullable, todo, util

The ClassToInstanceMap.java Java example source code

/*
 * 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.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

import java.util.Map;

import javax.annotation.Nullable;

/**
 * A map, each entry of which maps a Java
 * <a href="http://tinyurl.com/2cmwkz">raw type 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>Like any other {@code Map}, this map may contain entries
 * for primitive types, and a primitive type and its corresponding wrapper type
 * may map to different values.
 *
 * <p>See the Guava User Guide article on , 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.
   */
  @CanIgnoreReturnValue // TODO(kak): Consider removing this?
  <T extends B> T getInstance(Class type);

  /**
   * Maps the specified class to the specified value. Does <i>not associate
   * this value with any of the class's supertypes.
   *
   * @return the value previously associated with this class (possibly {@code
   *     null}), or {@code null} if there was no previous entry.
   */
  @CanIgnoreReturnValue
  <T extends B> T putInstance(Class type, @Nullable T value);
}