org.springframework.data.domain.Page.java Source code

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Here is the source code for org.springframework.data.domain.Page.java

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/*
 * Copyright 2008-2019 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
 *
 *      https://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.springframework.data.domain;

import java.util.Collections;
import java.util.function.Function;

/**
 * A page is a sublist of a list of objects. It allows gain information about the position of it in the containing
 * entire list.
 *
 * @param <T>
 * @author Oliver Gierke
 */
public interface Page<T> extends Slice<T> {

    /**
     * Creates a new empty {@link Page}.
     *
     * @return
     * @since 2.0
     */
    static <T> Page<T> empty() {
        return empty(Pageable.unpaged());
    }

    /**
     * Creates a new empty {@link Page} for the given {@link Pageable}.
     *
     * @param pageable must not be {@literal null}.
     * @return
     * @since 2.0
     */
    static <T> Page<T> empty(Pageable pageable) {
        return new PageImpl<>(Collections.emptyList(), pageable, 0);
    }

    /**
     * Returns the number of total pages.
     *
     * @return the number of total pages
     */
    int getTotalPages();

    /**
     * Returns the total amount of elements.
     *
     * @return the total amount of elements
     */
    long getTotalElements();

    /**
     * Returns a new {@link Page} with the content of the current one mapped by the given {@link Function}.
     *
     * @param converter must not be {@literal null}.
     * @return a new {@link Page} with the content of the current one mapped by the given {@link Function}.
     * @since 1.10
     */
    <U> Page<U> map(Function<? super T, ? extends U> converter);
}