net.yetamine.lang.creational.Factory Maven / Gradle / Ivy
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package net.yetamine.lang.creational;
import java.util.Objects;
import java.util.function.Function;
import java.util.function.Supplier;
/**
* An interface for factories and builders.
*
*
* For convenience this interface inherits from {@link Supplier} and the
* inherited {@link #get()} method should be an alias to {@link #build()}.
*
* @param
* the type of the product
*/
@FunctionalInterface
public interface Factory extends Supplier {
/**
* Provides a new instance of the product.
*
*
* Technically, the result does not have to be a brand new instance if the
* result is immutable and may be shared. However, the result must be such
* an instance that it can be used by multiple clients without their mutual
* interference. This is an additional requirement that the {@link #get()}
* method does not impose.
*
* @return a new instance of the product
*/
T build();
/**
* @see java.util.function.Supplier#get()
*/
default T get() {
return build();
}
/**
* Makes a factory which uses a template object as the prototype for making
* more instances.
*
* @param
* the type of the product
* @param template
* the template for the builder. It must not be {@code null}.
* @param builder
* the builder which takes a template object and returns an
* independent copy of it. It must not be {@code null}.
*
* @return a factory using a template object
*/
static Factory prototype(T template, Function builder) {
Objects.requireNonNull(template);
Objects.requireNonNull(builder);
return () -> builder.apply(template);
}
}