com.jongsoft.utils.core.Value Maven / Gradle / Ivy
/*
* The MIT License
*
* Copyright 2016 Jong Soft.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.jongsoft.utils.core;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
*
* @param the type of object being wrapped
*/
public interface Value extends Iterable {
/**
* Return the contents T of the wrapped value.
*
* This can throw a {@link NoSuchElementException} if no value is present.
*
* @return returns the object wrapped in this value
* @throws NoSuchElementException if no element is present
*/
T get();
/**
* Indicates if a value is present within the wrapper
*
* @return true if an element is present, otherwise false
*/
boolean isPresent();
/**
* Process the present element wrapped within using the provided {@link Consumer}.
*
* @param consumer the method that will consume the element
* @return the {@link OrElse} functionality, which enables processing in case of {@link #isPresent() }
* being false.
*/
OrElse ifPresent(Consumer consumer);
/**
* Throw an exception if an element is present within. Otherwise it will return the {@link OrElse}.
*
* @param exceptionSupplier the supplier to create the exception
* @param the type of exception expected
* @return the {@link OrElse} in case no element is present
* @throws X the exception thrown if a present element
*/
OrElse ifPresent(Supplier exceptionSupplier) throws X;
/**
* Execute the runner method if no entity is present in this wrapped object
*
* @param runner the code to execute if nothing is present
* @throws NullPointerException in case the runner is null
*/
default void ifNotPresent(Runner runner) {
Objects.requireNonNull(runner, "Runner cannot be null");
if (!isPresent()) {
runner.run();
}
}
/**
* Throws an exception when no value is present in this value
*
* @param exceptionSupplier the supplier to create the exception
* @param the type of exception expected
* @throws X the exception thrown if no present element
* @throws NullPointerException in case the exceptionSupplier is null
*/
default void ifNotPresent(Supplier exceptionSupplier) throws X {
Objects.requireNonNull(exceptionSupplier, "Supplier of exceptions cannot be null");
if (!isPresent()) {
throw exceptionSupplier.get();
}
}
/**
* Create a stream of the value.
*
* @return
*/
default Stream stream() {
return StreamSupport.stream(spliterator(), false);
}
/**
* Validate if the value contains the provided item.
*
* @param element an element of type T, can be null
* @return true, if the element is contained within
*/
default boolean contains(T element) {
return is(e -> Objects.equals(e, element));
}
/**
* Validate that all elements contained within match the predicate provided.
*
* @param predicate the predicate to test with
* @return true if all elements match the predicate, otherwise false
*/
default boolean all(Predicate predicate) {
return !is(predicate.negate());
}
/**
* Validate if an element is contained that matches the provided predicate.
*
* @param predicate the predicate to validate with
* @return true, if any element is contained within that matches the predicate
* @throws NullPointerException in case the {@link Predicate} is null
*/
default boolean is(Predicate predicate) {
Objects.requireNonNull(predicate, "Predicate provided cannot be null");
for (T entity : this) {
if (predicate.test(entity)) {
return true;
}
}
return false;
}
}