001// License: GPL. For details, see LICENSE file. 002package org.openstreetmap.josm.io.session; 003 004import static org.openstreetmap.josm.tools.I18n.tr; 005 006import java.io.IOException; 007import java.io.InputStream; 008 009import javax.xml.xpath.XPath; 010import javax.xml.xpath.XPathConstants; 011import javax.xml.xpath.XPathExpression; 012import javax.xml.xpath.XPathExpressionException; 013import javax.xml.xpath.XPathFactory; 014 015import org.openstreetmap.josm.gui.io.importexport.OsmImporter; 016import org.openstreetmap.josm.gui.layer.Layer; 017import org.openstreetmap.josm.gui.layer.OsmDataLayer; 018import org.openstreetmap.josm.gui.progress.ProgressMonitor; 019import org.openstreetmap.josm.io.IllegalDataException; 020import org.openstreetmap.josm.io.session.SessionReader.ImportSupport; 021import org.openstreetmap.josm.tools.Utils; 022import org.w3c.dom.Element; 023 024/** 025 * Session importer for {@link OsmDataLayer}. 026 * @since 4685 027 */ 028public class OsmDataSessionImporter implements SessionLayerImporter { 029 030 @Override 031 public Layer load(Element elem, ImportSupport support, ProgressMonitor progressMonitor) throws IOException, IllegalDataException { 032 checkMetaVersion(elem); 033 String fileStr = extractFileName(elem, support); 034 return importData(new OsmImporter(), support, fileStr, progressMonitor); 035 } 036 037 /** 038 * Checks that element defines the expected version number. 039 * @param elem element to check 040 * @throws IllegalDataException if version is not the expected one 041 * @since 15377 042 */ 043 public static void checkMetaVersion(Element elem) throws IllegalDataException { 044 String version = elem.getAttribute("version"); 045 if (!"0.1".equals(version)) { 046 throw new IllegalDataException(tr("Version ''{0}'' of meta data for osm data layer is not supported. Expected: 0.1", version)); 047 } 048 } 049 050 /** 051 * Extract file name from element. 052 * @param elem element to parse 053 * @param support import/export support 054 * @return file name, if present 055 * @throws IllegalDataException if file name missing or empty 056 * @since 15377 057 */ 058 public static String extractFileName(Element elem, ImportSupport support) throws IllegalDataException { 059 try { 060 XPathFactory xPathFactory = XPathFactory.newInstance(); 061 XPath xpath = xPathFactory.newXPath(); 062 XPathExpression fileExp = xpath.compile("file/text()"); 063 String fileStr = (String) fileExp.evaluate(elem, XPathConstants.STRING); 064 if (Utils.isEmpty(fileStr)) { 065 throw new IllegalDataException(tr("File name expected for layer no. {0}", support.getLayerIndex())); 066 } 067 return fileStr; 068 } catch (XPathExpressionException e) { 069 throw new IllegalDataException(e); 070 } 071 } 072 073 /** 074 * Import data as a new layer. 075 * @param osmImporter OSM importer 076 * @param support import/export support 077 * @param fileStr file name to import 078 * @param progressMonitor progress monitor 079 * @return new layer 080 * @throws IOException in case of I/O error 081 * @throws IllegalDataException in case of illegal data 082 * @since 15377 083 */ 084 public static Layer importData(OsmImporter osmImporter, ImportSupport support, String fileStr, ProgressMonitor progressMonitor) 085 throws IOException, IllegalDataException { 086 try (InputStream in = support.getInputStream(fileStr)) { 087 OsmImporter.OsmImporterData importData = osmImporter.loadLayer( 088 in, support.getFile(fileStr), support.getLayerName(), progressMonitor); 089 090 support.addPostLayersTask(importData.getPostLayerTask()); 091 return importData.getLayer(); 092 } 093 } 094}