Java tutorial
/* * Copyright (C) 2010 Pavel Stastny * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package cz.incad.kramerius.utils.solr; import java.io.IOException; import java.io.InputStream; import java.io.StringWriter; import java.util.ArrayList; import java.util.List; import java.util.logging.Logger; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.TransformerException; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpression; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.apache.commons.httpclient.HttpClientError; import org.apache.http.HttpResponse; import org.apache.http.client.HttpResponseException; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; import cz.incad.kramerius.SolrAccess; import cz.incad.kramerius.utils.RESTHelper; import cz.incad.kramerius.utils.XMLUtils; import cz.incad.kramerius.utils.conf.KConfiguration; /** * Utility helper class for SolrAccess * @see SolrAccess * @author pavels */ public class SolrUtils { public static final Logger LOGGER = Logger.getLogger(SolrUtils.class.getName()); /** PID query */ public static final String UUID_QUERY = "q=PID:"; /** Handle query */ public static final String HANDLE_QUERY = "q=handle:"; /** Parent query */ public static final String PARENT_QUERY = "q=parent_pid:"; // factory instance static XPathFactory fact = XPathFactory.newInstance(); /** * Conscturcts XPath for disecting pid path * @return Compiled XPath expression * @throws XPathExpressionException Cannot compile xpath */ public static XPathExpression pidPathExpr() throws XPathExpressionException { XPathExpression pidPathExpr = fact.newXPath().compile("//arr[@name='pid_path']/str"); return pidPathExpr; } /** * Constructs XPath for disecting PID * @return Compiled XPath expression * @throws XPathExpressionException Cannot compile xpath */ public static XPathExpression docPidExpr() throws XPathExpressionException { XPathExpression pidExpr = fact.newXPath().compile("//str[@name='PID']"); return pidExpr; } public static XPathExpression elmPidExpr() throws XPathExpressionException { XPathExpression pidExpr = fact.newXPath().compile("str[@name='PID']"); return pidExpr; } /** * Constructs XPath for disecting model path * @return Compiled XPath expression * @throws XPathExpressionException Cannot compile xpath */ public static XPathExpression modelPathExpr() throws XPathExpressionException { XPathExpression pathExpr = fact.newXPath().compile("//arr[@name='model_path']/str"); return pathExpr; } /** * Disects pid paths from given parsed solr document * @return pid paths * @throws XPathExpressionException cannot disect pid paths */ public static List<String> disectPidPaths(Document parseDocument) throws XPathExpressionException { synchronized (parseDocument) { List<String> list = new ArrayList<String>(); NodeList paths = (org.w3c.dom.NodeList) pidPathExpr().evaluate(parseDocument, XPathConstants.NODESET); if (paths != null) { for (int i = 0, ll = paths.getLength(); i < ll; i++) { Node n = paths.item(i); String text = n.getTextContent(); list.add(text.trim()); } return list; } return new ArrayList<String>(); } } /** * Disect pid from given solr document * @param parseDocument Parsed solr document * @return PID * @throws XPathExpressionException cannot disect pid */ public static String disectPid(Document parseDocument) throws XPathExpressionException { synchronized (parseDocument) { Node pidNode = (Node) docPidExpr().evaluate(parseDocument, XPathConstants.NODE); if (pidNode != null) { Element pidElm = (Element) pidNode; return pidElm.getTextContent().trim(); } return null; } } public static String disectPid(Element topElem) throws XPathExpressionException { synchronized (topElem.getOwnerDocument()) { Element foundElement = XMLUtils.findElement(topElem, new XMLUtils.ElementsFilter() { @Override public boolean acceptElement(Element element) { return (element.getNodeName().equals("str") && element.getAttribute("name") != null && element.getAttribute("name").equals("PID")); } }); if (foundElement != null) { return foundElement.getTextContent().trim(); } else return null; } } /** * Disect models path from given solr document * @param parseDocument Parsed solr document * @return model paths * @throws XPathExpressionException cannot disect models path */ public static List<String> disectModelPaths(Document parseDocument) throws XPathExpressionException { synchronized (parseDocument) { List<String> list = new ArrayList<String>(); NodeList pathNodes = (NodeList) modelPathExpr().evaluate(parseDocument, XPathConstants.NODESET); if (pathNodes != null) { for (int i = 0, ll = pathNodes.getLength(); i < ll; i++) { Node n = pathNodes.item(i); String text = n.getTextContent(); list.add(text.trim()); } return list; } return new ArrayList<String>(); } } public static Document getSolrDataInternalOffset(String query, String offset) throws IOException, ParserConfigurationException, SAXException { String solrHost = KConfiguration.getInstance().getSolrHost(); String uri = solrHost + "/select?" + query + "&start=" + offset; InputStream inputStream = RESTHelper.inputStream(uri, "<no_user>", "<no_pass>"); Document parseDocument = XMLUtils.parseDocument(inputStream); return parseDocument; } public static Document getSolrDataInternal(String query) throws IOException, ParserConfigurationException, SAXException { String solrHost = KConfiguration.getInstance().getSolrHost(); String uri = solrHost + "/select?" + query; InputStream inputStream = RESTHelper.inputStream(uri, "<no_user>", "<no_pass>"); Document parseDocument = XMLUtils.parseDocument(inputStream); return parseDocument; } public static InputStream getSolrDataInternal(String query, String format) throws IOException { String solrHost = KConfiguration.getInstance().getSolrHost(); String uri = solrHost + "/select?" + query; if (!uri.endsWith("&")) { uri = uri + "&wt=" + format; } else { uri = uri + "wt=" + format; } HttpGet httpGet = new HttpGet(uri); CloseableHttpClient client = HttpClients.createDefault(); HttpResponse response = client.execute(httpGet); if (response.getStatusLine().getStatusCode() == 200) { return response.getEntity().getContent(); } else { throw new HttpResponseException(response.getStatusLine().getStatusCode(), response.getStatusLine().getReasonPhrase()); } } public static InputStream getSolrTermsInternal(String query, String format) throws IOException, ParserConfigurationException, SAXException { String solrHost = KConfiguration.getInstance().getSolrHost(); String uri = solrHost + "/terms?" + query; if (!uri.endsWith("&")) { uri = uri + "&wt=" + format; } else { uri = uri + "wt=" + format; } InputStream inputStream = RESTHelper.inputStream(uri, "<no_user>", "<no_pass>"); return inputStream; } }