org.wallride.web.support.Pagination.java Source code

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Here is the source code for org.wallride.web.support.Pagination.java

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/*
 * Copyright 2014 Tagbangers, Inc.
 *
 * 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.wallride.web.support;

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import javax.servlet.http.HttpServletRequest;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Pagination<T> {

    public static final int DEFAULT_INTERVAL = 5;

    private Page<T> page;
    private String url;

    public Pagination(Page<T> page, String url) {
        this.page = page;
        this.url = url;
    }

    public Pagination(Page<T> page, HttpServletRequest request) {
        this.page = page;
        this.url = ServletUriComponentsBuilder.fromRequest(request).replaceQueryParam("page").build().toUriString();
    }

    public String getUrl() {
        return url;
    }

    public int getCurrentPageNumber() {
        return page.getNumber();
    }

    public int getPreviousPageNumber() {
        return getCurrentPageNumber() - 1;
    }

    public int getNextPageNumber() {
        return getCurrentPageNumber() + 1;
    }

    public boolean hasPreviousPage() {
        return page.hasPrevious();
    }

    public boolean hasNextPage() {
        return page.hasNext();
    }

    public long getNumberOfFirstElement() {
        long number = 0;
        if (page.hasContent()) {
            number = page.getNumber() * page.getSize() + 1;
        }
        return number;
    }

    public long getNumberOfLastElement() {
        long number = 0;
        if (page.hasContent()) {
            number = getNumberOfFirstElement() + page.getNumberOfElements() - 1;
        }
        return number;
    }

    public long getTotalElements() {
        return page.getTotalElements();
    }

    public int getTotalPages() {
        return page.getTotalPages();
    }

    public List<Pageable> getPageables(Pageable currentPageable) {
        return getPageables(currentPageable, DEFAULT_INTERVAL);
    }

    public List<Pageable> getPageables(Pageable currentPageable, int interval) {
        List<Pageable> pageables = new ArrayList<>();

        int start = page.getNumber() - interval;
        if (start < 0) {
            start = 0;
        }
        int end = page.getNumber() + interval;
        if (end > page.getTotalPages() - 1) {
            end = page.getTotalPages() - 1;
        }

        Pageable p;
        p = currentPageable;
        for (int i = getCurrentPageNumber(); i > start; i--) {
            p = p.previousOrFirst();
            pageables.add(p);
        }

        Collections.reverse(pageables);
        pageables.add(currentPageable);

        p = currentPageable;
        for (int i = getCurrentPageNumber(); i < end; i++) {
            p = p.next();
            pageables.add(p);
        }

        return pageables;
    }
}