root / tags / v2_0_0_Build_2056 / libraries / libFMap_dal / src / org / gvsig / fmap / dal / feature / paging / impl / FeaturePagingHelperImpl.java @ 39017
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/* gvSIG. Geographic Information System of the Valencian Government
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*
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* Copyright (C) 2007-2008 Infrastructures and Transports Department
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* of the Valencian Government (CIT)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*
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*/
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/*
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* AUTHORS (In addition to CIT):
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* 2008 {DiSiD Technologies} {Create a JTable TableModel for a FeatureCollection}
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*/
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package org.gvsig.fmap.dal.feature.paging.impl; |
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import org.slf4j.Logger; |
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import org.slf4j.LoggerFactory; |
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import org.gvsig.fmap.dal.exception.DataException; |
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import org.gvsig.fmap.dal.feature.EditableFeature; |
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import org.gvsig.fmap.dal.feature.Feature; |
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import org.gvsig.fmap.dal.feature.FeatureQuery; |
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import org.gvsig.fmap.dal.feature.FeatureSelection; |
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import org.gvsig.fmap.dal.feature.FeatureSet; |
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import org.gvsig.fmap.dal.feature.FeatureStore; |
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import org.gvsig.fmap.dal.feature.FeatureType; |
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import org.gvsig.fmap.dal.feature.impl.featureset.DynObjectFeatureFacade; |
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import org.gvsig.fmap.dal.feature.paging.FeaturePagingHelper; |
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import org.gvsig.tools.dynobject.DynObject; |
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import org.gvsig.tools.dynobject.DynObjectSet; |
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import org.gvsig.tools.dynobject.impl.DefaultDynObjectPagingHelper; |
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import org.gvsig.tools.exception.BaseException; |
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import org.gvsig.tools.visitor.VisitCanceledException; |
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import org.gvsig.tools.visitor.Visitor; |
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/**
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* Helper class to access the values of a FeatureCollection by position. Handles
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* pagination automatically to avoid filling the memory in case of big
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* collections.
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*
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* TODO: evaluate if its more convenient to read values in the background when
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* the returned value is near the end of the page, instead of loading a page on
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* demand.
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*
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* @author gvSIG Team
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*/
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public class FeaturePagingHelperImpl extends DefaultDynObjectPagingHelper |
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implements FeaturePagingHelper {
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private static final Logger LOG = LoggerFactory |
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.getLogger(FeaturePagingHelperImpl.class); |
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private FeatureQuery query;
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private FeatureStore featureStore;
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/** If the selected Features must be returned as the first ones. **/
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private boolean selectionUp = false; |
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private FeatureSelection initialSelection = null; |
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private Feature[] features = null; |
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/**
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* Constructs a FeaturePagingHelperImpl from data of a FeatureStore.
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*
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* @param featureStore
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* to extract data from
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* @throws DataException
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* if there is an error initializing the helper
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*/
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public FeaturePagingHelperImpl(FeatureStore featureStore)
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throws BaseException {
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this(featureStore, DEFAULT_PAGE_SIZE);
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} |
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/**
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* Constructs a FeaturePagingHelperImpl from data of a FeatureStore.
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*
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* @param featureStore
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* to extract data from
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* @param pageSize
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* the number of elements per page data
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* @throws DataException
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* if there is an error initializing the helper
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*/
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public FeaturePagingHelperImpl(FeatureStore featureStore, int pageSize) |
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throws BaseException {
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this(featureStore, null, pageSize); |
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} |
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/**
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* Constructs a FeaturePagingHelperImpl from data of a FeatureStore.
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*
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* @param featureStore
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* to extract data from
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* @throws DataException
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* if there is an error initializing the helper
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*/
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public FeaturePagingHelperImpl(FeatureStore featureStore,
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FeatureQuery featureQuery) throws BaseException {
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this(featureStore, featureQuery, DEFAULT_PAGE_SIZE);
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} |
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/**
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* Constructs a FeaturePagingHelperImpl from data of a FeatureStore.
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*
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* @param featureSet
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* to extract data from
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* @param pageSize
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* the number of elements per page data
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* @throws DataException
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* if there is an error initializing the helper
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*/
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public FeaturePagingHelperImpl(FeatureStore featureStore,
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FeatureQuery featureQuery, int pageSize) throws BaseException { |
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super();
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FeatureQuery query = featureQuery; |
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if (featureQuery == null) { |
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query = featureStore.createFeatureQuery(); |
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query.setFeatureType(featureStore.getDefaultFeatureType()); |
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} |
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this.featureStore = featureStore;
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this.query = query;
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this.query.setPageSize(pageSize);
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if (LOG.isDebugEnabled()) {
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LOG.debug("FeaturePagingHelperImpl created with {} pages, "
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+ "and a page size of {}", new Long(getCalculator() |
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.getNumPages()), new Integer(pageSize)); |
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} |
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setDefaultCalculator(new Sizeable() {
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public long getSize() { |
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FeatureSet featureSet = getFeatureSet(); |
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try {
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return featureSet.getSize();
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} catch (BaseException e) {
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LOG.error("Error getting the size of the FeatureSet: "
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+ featureSet, e); |
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return 0l; |
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} |
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} |
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}, pageSize); |
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} |
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/**
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* @return the selectionUp status
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*/
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protected boolean isSelectionUp() { |
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return selectionUp;
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} |
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public void setSelectionUp(boolean selectionUp) { |
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this.selectionUp = selectionUp;
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try {
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if (selectionUp) {
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initialSelection = |
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(FeatureSelection) getFeatureStore().getFeatureSelection() |
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.clone(); |
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setCalculator(new OneSubsetOneSetPagingCalculator(
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new FeatureSetSizeableDelegate(initialSelection),
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new FeatureSetSizeableDelegate(getFeatureSet()),
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getMaxPageSize())); |
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} else {
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if (initialSelection != null) { |
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initialSelection.dispose(); |
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initialSelection = null;
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} |
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setDefaultCalculator(new FeatureSetSizeableDelegate(
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getFeatureSet()), getMaxPageSize()); |
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} |
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} catch (BaseException e) {
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LOG.error("Error setting the selection up setting to: "
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+ selectionUp, e); |
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} catch (CloneNotSupportedException e) { |
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LOG.error("Error cloning the selection "
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+ "while setting the selection up", e);
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} |
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} |
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public Feature getFeatureAt(long index) throws BaseException { |
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// Check if we have currently loaded the viewed page data,
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// or we need to load a new one
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long pageForIndex = (long) Math.floor(index / getMaxPageSize()); |
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if (pageForIndex != getCurrentPage()) {
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setCurrentPage(pageForIndex); |
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} |
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long positionForIndex = index - (getCurrentPage() * getMaxPageSize());
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return features[(int) positionForIndex]; |
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} |
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public Feature[] getCurrentPageFeatures() { |
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return features;
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} |
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private FeatureSet getFeatureSet() {
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try {
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FeatureStore featureStore = getFeatureStore(); |
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synchronized (featureStore) {
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return featureStore.getFeatureSet(getFeatureQuery());
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} |
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} catch (DataException e) {
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throw new RuntimeException("Error getting a feature set with the query " + getFeatureQuery()); |
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} |
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} |
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public DynObjectSet getDynObjectSet() {
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return getFeatureSet().getDynObjectSet();
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} |
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public void reloadCurrentPage() throws BaseException { |
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setSelectionUp(false);
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if (getCalculator().getCurrentPage() > -1) { |
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loadCurrentPageData(); |
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} |
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} |
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public void reload() throws BaseException { |
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setDefaultCalculator(new Sizeable() {
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public long getSize() { |
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FeatureSet featureSet = getFeatureSet(); |
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try {
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return featureSet.getSize();
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} catch (BaseException e) {
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LOG.error("Error getting the size of the FeatureSet: "
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+ featureSet, e); |
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return 0l; |
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} |
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} |
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}, getCalculator().getMaxPageSize()); |
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reloadCurrentPage(); |
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} |
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public FeatureStore getFeatureStore() {
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return featureStore;
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} |
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public FeatureQuery getFeatureQuery() {
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return query;
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} |
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/**
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* Loads all the Features of the current page.
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*/
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protected void loadCurrentPageData() throws BaseException { |
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final int currentPageSize = getCalculator().getCurrentPageSize(); |
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final Feature[] values = new Feature[currentPageSize]; |
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long t1 = 0; |
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if (LOG.isTraceEnabled()) {
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t1 = System.currentTimeMillis();
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} |
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if (selectionUp) {
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loadCurrentPageDataWithSelectionUp(values); |
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} else {
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loadCurrentPageDataNoSelection(values); |
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} |
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if (LOG.isTraceEnabled()) {
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long t2 = System.currentTimeMillis(); |
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LOG.trace("Time to load {} features: {} ms", new Integer( |
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currentPageSize), new Long(t2 - t1)); |
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} |
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this.features = values;
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} |
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private void loadCurrentPageDataWithSelectionUp(final Feature[] values) |
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throws BaseException {
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FeatureSelection selection = initialSelection; |
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FeatureSet set = getFeatureSet(); |
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try {
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OneSubsetOneSetPagingCalculator twoSetsCalculator = null;
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if (getCalculator() instanceof OneSubsetOneSetPagingCalculator) { |
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twoSetsCalculator = |
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(OneSubsetOneSetPagingCalculator) getCalculator(); |
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} else {
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twoSetsCalculator = |
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new OneSubsetOneSetPagingCalculator(
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new FeatureSetSizeableDelegate(selection),
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new FeatureSetSizeableDelegate(set),
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getMaxPageSize(), getCalculator().getCurrentPage()); |
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setCalculator(twoSetsCalculator); |
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} |
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// First load values from the selection, if the current page has
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// elements from it
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if (twoSetsCalculator.hasCurrentPageAnyValuesInFirstSet()) {
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loadDataFromFeatureSet(values, 0, selection,
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twoSetsCalculator.getFirstSetInitialIndex(), |
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twoSetsCalculator.getFirstSetHowMany(), null);
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} |
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// Next, load values from the FeatureSet if the current page has values
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// from it
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if (twoSetsCalculator.hasCurrentPageAnyValuesInSecondSet()) {
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loadDataFromFeatureSet( |
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values, |
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// The cast will work as that size will be <= maxpagesize,
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// which is an int
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(int) twoSetsCalculator.getFirstSetHowMany(), set,
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twoSetsCalculator.getSecondSetInitialIndex(), |
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twoSetsCalculator.getSecondSetHowMany(), selection); |
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} |
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} finally {
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set.dispose(); |
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} |
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} |
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private void loadCurrentPageDataNoSelection(final Feature[] values) |
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throws BaseException {
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long firstPosition = getCalculator().getInitialIndex();
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if (LOG.isDebugEnabled()) {
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LOG.debug("Loading {} Features starting at position {}",
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new Integer(getCalculator().getCurrentPageSize()), new Long( |
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firstPosition)); |
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} |
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FeatureSet featureSet = getFeatureSet(); |
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try {
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loadDataFromFeatureSet(values, 0, featureSet, firstPosition,
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getCalculator().getCurrentPageSize(), null);
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} finally {
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featureSet.dispose(); |
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} |
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} |
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private void loadDataFromFeatureSet(final Feature[] values, |
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final int valuesPosition, FeatureSet set, long initialIndex, |
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final long howMany, final FeatureSelection selectedFeaturesToSkip) |
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throws DataException {
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try {
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set.accept(new Visitor() {
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private int i = valuesPosition; |
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public void visit(Object obj) throws VisitCanceledException, |
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BaseException { |
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if (i >= valuesPosition + howMany) {
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throw new VisitCanceledException(); |
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} |
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Feature current = (Feature) obj; |
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// Add the current Feature only if we don't skip selected
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// features or the feature is not selected
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if (selectedFeaturesToSkip == null |
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|| !selectedFeaturesToSkip.isSelected(current)) { |
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values[i] = current.getCopy(); |
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i++; |
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} |
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} |
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}, initialIndex); |
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} catch (BaseException e) {
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if (e instanceof DataException) { |
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throw ((DataException) e);
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} else {
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LOG.error("Error loading the data starting at position {}",
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new Long(initialIndex), e); |
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} |
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} |
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} |
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public void delete(Feature feature) throws BaseException { |
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featureStore.delete(feature); |
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reloadCurrentPage(); |
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} |
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public void insert(EditableFeature feature) throws BaseException { |
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featureStore.insert(feature); |
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reloadCurrentPage(); |
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} |
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public void update(EditableFeature feature) throws BaseException { |
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featureStore.update(feature); |
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reloadCurrentPage(); |
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} |
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public FeatureType getFeatureType() {
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FeatureSet featureSet = getFeatureSet(); |
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try {
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return featureSet.getDefaultFeatureType();
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} finally {
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featureSet.dispose(); |
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} |
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} |
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protected void doDispose() throws BaseException { |
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initialSelection.dispose(); |
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} |
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public DynObject[] getCurrentPageDynObjects() { |
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Feature[] features = getCurrentPageFeatures();
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DynObject[] dynobjects = new DynObject[features.length]; |
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for (int i = 0; i < dynobjects.length; i++) { |
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dynobjects[i] = new DynObjectFeatureFacade(features[i]);
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} |
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return dynobjects;
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} |
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public DynObject getDynObjectAt(long index) throws BaseException { |
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return new DynObjectFeatureFacade(getFeatureAt(index)); |
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} |
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} |