001    /*
002     * SonarQube, open source software quality management tool.
003     * Copyright (C) 2008-2014 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * SonarQube is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * SonarQube is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public License
017     * along with this program; if not, write to the Free Software Foundation,
018     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019     */
020    
021    package org.sonar.api.utils;
022    
023    /**
024     * @since 3.6
025     */
026    public class Paging {
027    
028      private final int pageSize;
029      private final int pageIndex;
030      private final int total;
031    
032      private Paging(int pageSize, int pageIndex, int total) {
033        this.pageSize = pageSize;
034        this.pageIndex = pageIndex;
035        this.total = total;
036      }
037    
038      /**
039       * Page index, starting with 1.
040       */
041      public int pageIndex() {
042        return pageIndex;
043      }
044    
045      /**
046       * Maximum number of items per page. It is greater than 0.
047       */
048      public int pageSize() {
049        return pageSize;
050      }
051    
052      /**
053       * Total number of items. It is greater than or equal 0.
054       */
055      public int total() {
056        return total;
057      }
058    
059      public int offset(){
060        return (pageIndex - 1) * pageSize;
061      }
062    
063      /**
064       * Number of pages. It is greater than or equal 0.
065       */
066      public int pages() {
067        int p = total / pageSize;
068        if (total % pageSize > 0) {
069          p++;
070        }
071        return p;
072      }
073    
074      /**
075       *
076       * @since 4.1
077       */
078      public boolean hasNextPage(){
079        return pageIndex() < pages();
080      }
081    
082      public static Paging create(int pageSize, int pageIndex, int totalItems) {
083        if (pageSize<1) {
084          throw new IllegalArgumentException("Page size must be strictly positive. Got " + pageSize);
085        }
086        if (pageIndex<1) {
087          throw new IllegalArgumentException("Page index must be strictly positive. Got " + pageIndex);
088        }
089        if (totalItems<0) {
090          throw new IllegalArgumentException("Total items must be positive. Got " + totalItems);
091        }
092        return new Paging(pageSize, pageIndex, totalItems);
093      }
094    }