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

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

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/*
 * Copyright 2008-2014 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.springframework.data.domain;

import java.util.List;

import com.fasterxml.jackson.annotation.JsonProperty;

/**
 * Basic {@code Page} implementation.
 * 
 * @param <T>
 *            the type of which the page consists.
 * @author Oliver Gierke
 */
public class PageImpl<T> extends Chunk<T> implements Page<T> {

    private static final long serialVersionUID = 867755909294344406L;

    private final long total;

    /**
     * Constructor of {@code PageImpl}.
     * 
     * @param content
     *            the content of this page, must not be {@literal null}.
     * @param pageable
     *            the paging information, can be {@literal null}.
     * @param total
     *            the total amount of items available
     */
    public PageImpl(List<T> content, Pageable pageable, long total) {

        super(content, pageable);
        this.total = total;
    }

    /**
     * Creates a new {@link PageImpl} with the given content. This will result
     * in the created {@link Page} being identical to the entire {@link List}.
     * 
     * @param content
     *            must not be {@literal null}.
     */
    public PageImpl(List<T> content) {
        this(content, null, null == content ? 0 : content.size());
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#getTotalPages()
     */
    @Override
    public int getTotalPages() {
        return getSize() == 0 ? 1 : (int) Math.ceil((double) total / (double) getSize());
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#getTotalElements()
     */
    @Override
    public long getTotalElements() {
        return total;
    }

    public long getTotal() {
        return total;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Slice#hasNext()
     */
    @Override
    public boolean hasNext() {
        return getNumber() + 1 < getTotalPages();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Slice#isLast()
     */
    @Override
    public boolean isLast() {
        return !hasNext();
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {

        String contentType = "UNKNOWN";
        List<T> content = getContent();

        if (content.size() > 0) {
            contentType = content.get(0).getClass().getName();
        }

        return String.format("Page %s of %d containing %s instances", getNumber(), getTotalPages(), contentType);
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {

        if (this == obj) {
            return true;
        }

        if (!(obj instanceof PageImpl<?>)) {
            return false;
        }

        PageImpl<?> that = (PageImpl<?>) obj;

        return this.total == that.total && super.equals(obj);
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {

        int result = 17;

        result += 31 * (int) (total ^ total >>> 32);
        result += 31 * super.hashCode();

        return result;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#hasPreviousPage()
     */
    public boolean hasPreviousPage() {
        return getNumber() > 0;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#isFirstPage()
     */
    public boolean isFirstPage() {
        return !hasPreviousPage();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#hasNextPage()
     */
    public boolean hasNextPage() {
        return getNumber() + 1 < getTotalPages();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.springframework.data.domain.Page#isLastPage()
     */
    public boolean isLastPage() {
        return !hasNextPage();
    }

    @JsonProperty(value = "rows")
    @Override
    public List<T> getContent() {
        return super.getContent();
    }

}