Java tutorial
/* * Copyright 2004 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 com.googlecode.jtiger.modules.ecside.table.callback; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.List; import org.apache.commons.beanutils.BeanComparator; import org.apache.commons.collections.CollectionUtils; import org.apache.commons.collections.comparators.NullComparator; import org.apache.commons.collections.comparators.ReverseComparator; import org.apache.commons.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.googlecode.jtiger.modules.ecside.core.RetrievalUtils; import com.googlecode.jtiger.modules.ecside.core.TableConstants; import com.googlecode.jtiger.modules.ecside.core.TableModel; import com.googlecode.jtiger.modules.ecside.core.bean.Table; import com.googlecode.jtiger.modules.ecside.table.limit.Sort; /** * The default implementation of the callbacks that handle the retrieving, * filtering, and sorting of the collection that gets passed to the * eXtremeTable. * * @author Jeff Johnston */ @SuppressWarnings("unchecked") public class ProcessRowsCallback implements RetrieveRowsCallback, FilterRowsCallback, SortRowsCallback { private Log logger = LogFactory.getLog(ProcessRowsCallback.class); public Collection retrieveRows(TableModel model) throws Exception { Table table = model.getTable(); return RetrievalUtils.retrieveCollection(model.getContext(), table.getItems(), table.getScope()); } public Collection filterRows(TableModel model, Collection rows) throws Exception { boolean filtered = model.getLimit().isFiltered(); boolean cleared = model.getLimit().isCleared(); if (!filtered || cleared) { return rows; } if (filtered) { Collection collection = new ArrayList(); FilterPredicate filterPredicate = new FilterPredicate(model); CollectionUtils.select(rows, filterPredicate, collection); return collection; } return rows; } public Collection sortRows(TableModel model, Collection rows) throws Exception { boolean sorted = model.getLimit().isSorted(); if (!sorted) { return rows; } Sort sort = model.getLimit().getSort(); String property = sort.getProperty(); String sortOrder = sort.getSortOrder(); if (StringUtils.contains(property, ".")) { try { if (sortOrder.equals(TableConstants.SORT_ASC)) { Collections.sort((List) rows, new NullSafeBeanComparator(property, new NullComparator())); } else if (sortOrder.equals(TableConstants.SORT_DESC)) { NullSafeBeanComparator reversedNaturalOrderBeanComparator = new NullSafeBeanComparator(property, new ReverseComparator(new NullComparator())); Collections.sort((List) rows, reversedNaturalOrderBeanComparator); } } catch (NoClassDefFoundError e) { String msg = "The column property [" + property + "] is nested and requires BeanUtils 1.7 or greater for proper sorting."; logger.error(msg); throw new NoClassDefFoundError(msg); //just rethrow so it is not hidden } } else { if (sortOrder.equals(TableConstants.SORT_ASC)) { BeanComparator comparator = new BeanComparator(property, new NullComparator()); Collections.sort((List) rows, comparator); } else if (sortOrder.equals(TableConstants.SORT_DESC)) { BeanComparator reversedNaturalOrderBeanComparator = new BeanComparator(property, new ReverseComparator(new NullComparator())); Collections.sort((List) rows, reversedNaturalOrderBeanComparator); } } return rows; } }