javascalautils.concurrent.PromiseCompanion Maven / Gradle / Ivy
/**
* Copyright 2015 Peter Nerg
*
* 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 javascalautils.concurrent;
/**
* Acts as a Scala type companion object for {@link Promise}.
* The primary purpose is to get the Scala feel of instantiating classes.
* In Scala you can define a companion object for a class, acting as a static reference/singleton
* for that class allowing you do define factory methods.
* One use case is to define methods with the same name as the class and let these methods invoke
* the constructor thus creating a nice way to create instances without using the word "new".
* This can be achieved in java by statically importing a method and then using it.
* The limitation is that classes may not have method with the same name as the class itself hence
* new companion classes have to be created.
* To be able to use it in a neat concise way one needs to statically import the method.
*
*
*
*
* import static javascalautils.PromiseCompanion.Promise;
*
* Promise<String> promise = Promise();
*
*
*
*
* @author Peter Nerg
* @since 1.3
*/
public final class PromiseCompanion {
private PromiseCompanion() {}
/**
* Creates an instance of Promise.
* Best used in conjunction with statically importing this method.
*
*
*
*
* import static javascalautils.concurrent.FutureCompanion.Promise;
*
* Promise<String> promise = Promise();
*
*
*
*
* @param The type the Promise is expected to deliver
* @return The Promise instance
* @since 1.3
*/
public static Promise Promise() {
return Promise.apply();
}
}