Java tutorial
/* * Copyright 2014-2015 the original author or 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 org.mytms.common.data; import org.springframework.core.convert.converter.Converter; import java.util.List; import java.util.function.Function; /** * A slice of data that indicates whether there's a next or previous slice available. Allows to obtain a * {@link Pageable} to request a previous or next {@link Slice}. * * @author Oliver Gierke * @since 1.8 */ public interface Slice<T> extends Iterable<T> { /** * Returns the number of the current {@link Slice}. Is always non-negative. * * @return the number of the current {@link Slice}. */ int getNumber(); /** * Returns the size of the {@link Slice}. * * @return the size of the {@link Slice}. */ int getSize(); /** * Returns the number of elements currently on this {@link Slice}. * * @return the number of elements currently on this {@link Slice}. */ int getNumberOfElements(); /** * Returns the page content as {@link List}. * * @return */ List<T> getContent(); /** * Returns whether the {@link Slice} has content at all. * * @return */ boolean hasContent(); /** * Returns the sorting parameters for the {@link Slice}. * * @return */ Sort getSort(); /** * Returns whether the current {@link Slice} is the first one. * * @return */ boolean isFirst(); /** * Returns whether the current {@link Slice} is the last one. * * @return */ boolean isLast(); /** * Returns if there is a next {@link Slice}. * * @return if there is a next {@link Slice}. */ boolean hasNext(); /** * Returns if there is a previous {@link Slice}. * * @return if there is a previous {@link Slice}. */ boolean hasPrevious(); /** * Returns the {@link Pageable} to request the next {@link Slice}. Can be {@literal null} in case the current * {@link Slice} is already the last one. Clients should check {@link #hasNext()} before calling this method to make * sure they receive a non-{@literal null} value. * * @return */ Pageable nextPageable(); /** * Returns the {@link Pageable} to request the previous {@link Slice}. Can be {@literal null} in case the current * {@link Slice} is already the first one. Clients should check {@link #hasPrevious()} before calling this method make * sure receive a non-{@literal null} value. * * @return */ Pageable previousPageable(); /** * Returns a new {@link Slice} with the content of the current one mapped by the given {@link Converter}. * * @param converter must not be {@literal null}. * @return a new {@link Slice} with the content of the current one mapped by the given {@link Converter}. * @since 1.10 */ <U> Slice<U> map(Function<? super T, ? extends U> converter); }