Java tutorial
/** * The contents of this file are subject to the license and copyright * detailed in the LICENSE and NOTICE files at the root of the source * tree and available online at * * http://www.dspace.org/license/ */ package org.dspace.content.authority; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.io.File; import org.apache.commons.lang.ArrayUtils; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.xml.sax.InputSource; import org.apache.log4j.Logger; import org.dspace.core.ConfigurationManager; import org.dspace.core.SelfNamedPlugin; /** * ChoiceAuthority source that reads the JSPUI-style hierarchical vocabularies * from ${dspace.dir}/config/controlled-vocabularies/*.xml and turns them into * autocompleting authorities. * * Configuration: * This MUST be configured as a self-named plugin, e.g.: * plugin.selfnamed.org.dspace.content.authority.ChoiceAuthority = \ * org.dspace.content.authority.DSpaceControlledVocabulary * * It AUTOMATICALLY configures a plugin instance for each XML file in the * controlled vocabularies directory. The name of the plugin is the basename * of the file; e.g., "${dspace.dir}/config/controlled-vocabularies/nsi.xml" * would generate a plugin called "nsi". * * Each configured plugin comes with three configuration options: * vocabulary.plugin._plugin_.hierarchy.store = <true|false> # Store entire hierarchy along with selected value. Default: TRUE * vocabulary.plugin._plugin_.hierarchy.suggest = <true|false> # Display entire hierarchy in the suggestion list. Default: TRUE * vocabulary.plugin._plugin_.delimiter = "<string>" # Delimiter to use when building hierarchy strings. Default: "::" * * * @author Michael B. Klein * */ public class DSpaceControlledVocabulary extends SelfNamedPlugin implements ChoiceAuthority { private static Logger log = Logger.getLogger(DSpaceControlledVocabulary.class); private static String xpathTemplate = "//node[contains(translate(@label,'ABCDEFGHIJKLMNOPQRSTUVWXYZ','abcdefghijklmnopqrstuvwxyz'),'%s')]"; private static String idTemplate = "//node[@id = '%s']"; private static String pluginNames[] = null; private String vocabularyName = null; private InputSource vocabulary = null; private Boolean suggestHierarchy = true; private Boolean storeHierarchy = true; private String hierarchyDelimiter = "::"; public DSpaceControlledVocabulary() { super(); } public static String[] getPluginNames() { if (pluginNames == null) { initPluginNames(); } return (String[]) ArrayUtils.clone(pluginNames); } private static synchronized void initPluginNames() { if (pluginNames == null) { class xmlFilter implements java.io.FilenameFilter { @Override public boolean accept(File dir, String name) { return name.endsWith(".xml"); } } String vocabulariesPath = ConfigurationManager.getProperty("dspace.dir") + "/config/controlled-vocabularies/"; String[] xmlFiles = (new File(vocabulariesPath)).list(new xmlFilter()); List<String> names = new ArrayList<String>(); for (String filename : xmlFiles) { names.add((new File(filename)).getName().replace(".xml", "")); } pluginNames = names.toArray(new String[names.size()]); log.info("Got plugin names = " + Arrays.deepToString(pluginNames)); } } private void init() { if (vocabulary == null) { log.info("Initializing " + this.getClass().getName()); vocabularyName = this.getPluginInstanceName(); String vocabulariesPath = ConfigurationManager.getProperty("dspace.dir") + "/config/controlled-vocabularies/"; String configurationPrefix = "vocabulary.plugin." + vocabularyName; storeHierarchy = ConfigurationManager.getBooleanProperty(configurationPrefix + ".hierarchy.store", storeHierarchy); suggestHierarchy = ConfigurationManager.getBooleanProperty(configurationPrefix + ".hierarchy.suggest", suggestHierarchy); String configuredDelimiter = ConfigurationManager.getProperty(configurationPrefix + ".delimiter"); if (configuredDelimiter != null) { hierarchyDelimiter = configuredDelimiter.replaceAll("(^\"|\"$)", ""); } String filename = vocabulariesPath + vocabularyName + ".xml"; log.info("Loading " + filename); vocabulary = new InputSource(filename); } } private String buildString(Node node) { if (node.getNodeType() == Node.DOCUMENT_NODE) { return (""); } else { String parentValue = buildString(node.getParentNode()); Node currentLabel = node.getAttributes().getNamedItem("label"); if (currentLabel != null) { String currentValue = currentLabel.getNodeValue(); if (parentValue.equals("")) { return currentValue; } else { return (parentValue + this.hierarchyDelimiter + currentValue); } } else { return (parentValue); } } } @Override public Choices getMatches(String field, String text, int collection, int start, int limit, String locale) { init(); log.debug("Getting matches for '" + text + "'"); String xpathExpression = String.format(xpathTemplate, text.replaceAll("'", "'").toLowerCase()); XPath xpath = XPathFactory.newInstance().newXPath(); Choice[] choices; try { NodeList results = (NodeList) xpath.evaluate(xpathExpression, vocabulary, XPathConstants.NODESET); String[] authorities = new String[results.getLength()]; String[] values = new String[results.getLength()]; String[] labels = new String[results.getLength()]; for (int i = 0; i < results.getLength(); i++) { Node node = results.item(i); String hierarchy = this.buildString(node); if (this.suggestHierarchy) { labels[i] = hierarchy; } else { labels[i] = node.getAttributes().getNamedItem("label").getNodeValue(); } if (this.storeHierarchy) { values[i] = hierarchy; } else { values[i] = node.getAttributes().getNamedItem("label").getNodeValue(); } Node idAttr = node.getAttributes().getNamedItem("id"); if (null != idAttr) // 'id' is optional authorities[i] = idAttr.getNodeValue(); } int resultCount = labels.length - start; if ((limit > 0) && (resultCount > limit)) // limit = 0 means no limit resultCount = limit; choices = new Choice[resultCount]; if (resultCount > 0) { for (int i = 0; i < resultCount; i++) { choices[i] = new Choice(authorities[start + i], values[start + i], labels[start + i]); } } } catch (XPathExpressionException e) { choices = new Choice[0]; } return new Choices(choices, 0, choices.length, Choices.CF_AMBIGUOUS, false); } @Override public Choices getBestMatch(String field, String text, int collection, String locale) { init(); log.debug("Getting best match for '" + text + "'"); return getMatches(field, text, collection, 0, 2, locale); } @Override public String getLabel(String field, String key, String locale) { init(); String xpathExpression = String.format(idTemplate, key); XPath xpath = XPathFactory.newInstance().newXPath(); try { Node node = (Node) xpath.evaluate(xpathExpression, vocabulary, XPathConstants.NODE); return node.getAttributes().getNamedItem("label").getNodeValue(); } catch (XPathExpressionException e) { return (""); } } }