| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.oodt.commons.pagination; |
| |
| import java.util.List; |
| |
| /** |
| * @author mattmann |
| * @version $Revision$ |
| * |
| * <p> |
| * A set of utility methods to do pagination. |
| * </p> |
| * |
| */ |
| public final class PaginationUtils { |
| |
| private PaginationUtils() throws InstantiationException { |
| throw new InstantiationException("Don't construct utility classes!"); |
| } |
| |
| public static int hasRemainder(int divisor, int quotient) { |
| if (divisor % quotient != 0) { |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| public static int computeCurrentPage(int startIdx, int productsPerPage) { |
| return ((startIdx + 1) / productsPerPage) |
| + hasRemainder(startIdx + 1, productsPerPage); |
| } |
| |
| public static int computeCurrentWindow(int currPage, int pagesPerPage) { |
| return (currPage / pagesPerPage) + hasRemainder(currPage, pagesPerPage); |
| } |
| |
| public static int computeMinPage(int pagesPerPage, int currWindow) { |
| return (pagesPerPage * (currWindow - 1)) + 1; |
| } |
| |
| public static int computeMaxPage(int minPage, int pagesPerPage, |
| int lastIdx, int productsPerPage) { |
| return Math.min(minPage + (pagesPerPage - 1), computeCurrentPage( |
| lastIdx, productsPerPage)); |
| } |
| |
| public static int computeEndIdx(int currPage, int productsPerPage, |
| int totalProducts) { |
| return Math.min((currPage * productsPerPage) - 1, totalProducts - 1); |
| } |
| |
| public static int computePrevStartIdx(int minPage, int productsPerPage) { |
| int prevPage = Math.max(minPage - 2, 1); |
| return (prevPage * productsPerPage); |
| } |
| |
| public static int computeNextStartIdx(int maxPage, int productsPerPage) { |
| int nextPage = maxPage; |
| return (nextPage * productsPerPage); |
| |
| } |
| |
| public static List iterateFrom(final int startIndex, |
| final List originalList, int pageSize) { |
| final int totalSize = originalList.size(); |
| |
| int endIndex = startIndex + pageSize; |
| if (endIndex > totalSize) |
| endIndex = totalSize; |
| |
| return originalList.subList(startIndex, endIndex); |
| } |
| |
| public static int getTotalPage(List originalList, int pageSize) { |
| if (originalList == null || originalList.size() <= 0) |
| return 0; |
| final int totalSize = originalList.size(); |
| return ((totalSize - 1) / pageSize) + 1; |
| } |
| |
| public static int getTotalPage(int numTotal, int pageSize) { |
| if (numTotal <= 0) |
| return 0; |
| return ((numTotal - 1) / pageSize) + 1; |
| } |
| |
| } |