Java tutorial
/** * SolrSelectServlet * Copyright 2012 by Michael Peter Christen * First released 23.08.2012 at http://yacy.net * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program in the file lgpl21.txt * If not, see <http://www.gnu.org/licenses/>. */ package net.yacy.http.servlets; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.io.StringWriter; import java.io.Writer; import java.net.URL; import java.nio.charset.StandardCharsets; import java.util.Date; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.yacy.cora.federate.FederateSearchManager; import net.yacy.cora.federate.solr.Ranking; import net.yacy.cora.federate.solr.connector.EmbeddedSolrConnector; import net.yacy.cora.federate.solr.connector.SolrConnector; import net.yacy.cora.federate.solr.responsewriter.EnhancedXMLResponseWriter; import net.yacy.cora.federate.solr.responsewriter.GSAResponseWriter; import net.yacy.cora.federate.solr.responsewriter.GrepHTMLResponseWriter; import net.yacy.cora.federate.solr.responsewriter.HTMLResponseWriter; import net.yacy.cora.federate.solr.responsewriter.OpensearchResponseWriter; import net.yacy.cora.federate.solr.responsewriter.SnapshotImagesReponseWriter; import net.yacy.cora.federate.solr.responsewriter.YJsonResponseWriter; import net.yacy.data.UserDB; import net.yacy.search.Switchboard; import net.yacy.search.SwitchboardConstants; import net.yacy.search.query.AccessTracker; import net.yacy.search.query.QueryGoal; import net.yacy.search.query.QueryModifier; import net.yacy.search.query.SearchEvent; import net.yacy.search.schema.CollectionSchema; import net.yacy.search.schema.WebgraphSchema; import org.apache.commons.lang.StringUtils; import org.apache.solr.common.SolrDocumentList; import org.apache.solr.common.SolrException; import org.apache.solr.common.params.CommonParams; import org.apache.solr.common.params.DisMaxParams; import org.apache.solr.common.params.MultiMapSolrParams; import static org.apache.solr.common.params.MultiMapSolrParams.addParam; import org.apache.solr.common.util.NamedList; import org.apache.solr.core.SolrCore; import org.apache.solr.request.SolrQueryRequest; import org.apache.solr.request.SolrRequestInfo; import org.apache.solr.response.BinaryResponseWriter; import org.apache.solr.response.QueryResponseWriter; import org.apache.solr.response.ResultContext; import org.apache.solr.response.SolrQueryResponse; import org.apache.solr.response.XSLTResponseWriter; import org.apache.solr.search.DocList; import org.apache.solr.servlet.SolrRequestParsers; import org.apache.solr.servlet.cache.HttpCacheHeaderUtil; import org.apache.solr.servlet.cache.Method; import org.apache.solr.util.FastWriter; /* * taken from the Solr 3.6.0 code, which is now deprecated; * this is now done in Solr 4.x.x with org.apache.solr.servlet.SolrDispatchFilter * implemented as servlet */ public class SolrSelectServlet extends HttpServlet { private static final long serialVersionUID = 1L; public final static Map<String, QueryResponseWriter> RESPONSE_WRITER = new HashMap<String, QueryResponseWriter>(); static { RESPONSE_WRITER.putAll(SolrCore.DEFAULT_RESPONSE_WRITERS); XSLTResponseWriter xsltWriter = new XSLTResponseWriter(); OpensearchResponseWriter opensearchResponseWriter = new OpensearchResponseWriter(); @SuppressWarnings("rawtypes") NamedList initArgs = new NamedList(); xsltWriter.init(initArgs); RESPONSE_WRITER.put("xslt", xsltWriter); // try i.e. http://localhost:8090/solr/select?q=*:*&start=0&rows=10&wt=xslt&tr=json.xsl RESPONSE_WRITER.put("exml", new EnhancedXMLResponseWriter()); RESPONSE_WRITER.put("html", new HTMLResponseWriter()); RESPONSE_WRITER.put("snapshots", new SnapshotImagesReponseWriter()); RESPONSE_WRITER.put("grephtml", new GrepHTMLResponseWriter()); RESPONSE_WRITER.put("rss", opensearchResponseWriter); //try http://localhost:8090/solr/select?wt=rss&q=olympia&hl=true&hl.fl=text_t,h1,h2 RESPONSE_WRITER.put("opensearch", opensearchResponseWriter); //try http://localhost:8090/solr/select?wt=rss&q=olympia&hl=true&hl.fl=text_t,h1,h2 RESPONSE_WRITER.put("yjson", new YJsonResponseWriter()); //try http://localhost:8090/solr/select?wt=yjson&q=olympia&hl=true&hl.fl=text_t,h1,h2 RESPONSE_WRITER.put("gsa", new GSAResponseWriter()); } @Override public void service(ServletRequest request, ServletResponse response) throws IOException, ServletException { HttpServletRequest hrequest = (HttpServletRequest) request; HttpServletResponse hresponse = (HttpServletResponse) response; SolrQueryRequest req = null; final Method reqMethod = Method.getMethod(hrequest.getMethod()); Writer out = null; try { // prepare request to solr MultiMapSolrParams mmsp = SolrRequestParsers.parseQueryString(hrequest.getQueryString()); Switchboard sb = Switchboard.getSwitchboard(); // TODO: isUserInRole needs a login to jetty container (not done automatically on admin from localhost) boolean authenticated = hrequest.isUserInRole(UserDB.AccessRight.ADMIN_RIGHT.toString()); // count remote searches if this was part of a p2p search if (mmsp.getMap().containsKey("partitions")) { final int partitions = mmsp.getInt("partitions", 30); sb.searchQueriesGlobal += 1.0f / partitions; // increase query counter } // get the ranking profile id int profileNr = mmsp.getInt("profileNr", 0); // rename post fields according to result style String querystring = ""; if (!mmsp.getMap().containsKey(CommonParams.Q) && mmsp.getMap().containsKey(CommonParams.QUERY)) { querystring = mmsp.get(CommonParams.QUERY, ""); mmsp.getMap().remove(CommonParams.QUERY); QueryModifier modifier = new QueryModifier(0); querystring = modifier.parse(querystring); modifier.apply(mmsp); QueryGoal qg = new QueryGoal(querystring); StringBuilder solrQ = qg.collectionTextQuery(); mmsp.getMap().put(CommonParams.Q, new String[] { solrQ.toString() }); // sru patch // experimental p2p enrichment if flag to do so is set /* final String p2pQuery = querystring; new Thread() { @Override public void run() { FederateSearchManager.getManager().query(p2pQuery); } }.start(); */ } String q = mmsp.get(CommonParams.Q, ""); if (querystring.length() == 0) querystring = q; if (!mmsp.getMap().containsKey(CommonParams.START)) { int startRecord = mmsp.getFieldInt("startRecord", null, 0); mmsp.getMap().remove("startRecord"); mmsp.getMap().put(CommonParams.START, new String[] { Integer.toString(startRecord) }); // sru patch } if (!mmsp.getMap().containsKey(CommonParams.ROWS)) { int maximumRecords = mmsp.getFieldInt("maximumRecords", null, 10); mmsp.getMap().remove("maximumRecords"); mmsp.getMap().put(CommonParams.ROWS, new String[] { Integer.toString(maximumRecords) }); // sru patch } mmsp.getMap().put(CommonParams.ROWS, new String[] { Integer .toString(Math.min(mmsp.getInt(CommonParams.ROWS, 10), (authenticated) ? 100000000 : 100)) }); // set ranking according to profile number if ranking attributes are not given in the request Ranking ranking = sb.index.fulltext().getDefaultConfiguration().getRanking(profileNr); if (!mmsp.getMap().containsKey(CommonParams.SORT) && !mmsp.getMap().containsKey(DisMaxParams.BQ) && !mmsp.getMap().containsKey(DisMaxParams.BF) && !mmsp.getMap().containsKey("boost")) { if (!mmsp.getMap().containsKey("defType")) mmsp.getMap().put("defType", new String[] { "edismax" }); String fq = ranking.getFilterQuery(); String bq = ranking.getBoostQuery(); String bf = ranking.getBoostFunction(); if (fq.length() > 0) mmsp.getMap().put(CommonParams.FQ, new String[] { fq }); if (bq.length() > 0) mmsp.getMap().put(DisMaxParams.BQ, StringUtils.split(bq, "\t\n\r\f")); // bq split into multiple query params, allowing space in single query if (bf.length() > 0) mmsp.getMap().put("boost", new String[] { bf }); // a boost function extension, see http://wiki.apache.org/solr/ExtendedDisMax#bf_.28Boost_Function.2C_additive.29 } // get a response writer for the result String wt = mmsp.get(CommonParams.WT, "xml"); // maybe use /solr/select?q=*:*&start=0&rows=10&wt=exml QueryResponseWriter responseWriter = RESPONSE_WRITER.get(wt); if (responseWriter == null) throw new ServletException("no response writer"); if (responseWriter instanceof OpensearchResponseWriter) { // set the title every time, it is possible that it has changed final String promoteSearchPageGreeting = (sb .getConfigBool(SwitchboardConstants.GREETING_NETWORK_NAME, false)) ? sb.getConfig("network.unit.description", "") : sb.getConfig(SwitchboardConstants.GREETING, ""); ((OpensearchResponseWriter) responseWriter).setTitle(promoteSearchPageGreeting); } // if this is a call to YaCys special search formats, enhance the query with field assignments if ((responseWriter instanceof YJsonResponseWriter || responseWriter instanceof OpensearchResponseWriter) && "true".equals(mmsp.get("hl", "true"))) { // add options for snippet generation if (!mmsp.getMap().containsKey("hl.q")) mmsp.getMap().put("hl.q", new String[] { q }); if (!mmsp.getMap().containsKey("hl.fl")) mmsp.getMap().put("hl.fl", new String[] { CollectionSchema.description_txt.getSolrFieldName() + "," + CollectionSchema.h4_txt.getSolrFieldName() + "," + CollectionSchema.h3_txt.getSolrFieldName() + "," + CollectionSchema.h2_txt.getSolrFieldName() + "," + CollectionSchema.h1_txt.getSolrFieldName() + "," + CollectionSchema.text_t.getSolrFieldName() }); if (!mmsp.getMap().containsKey("hl.alternateField")) mmsp.getMap().put("hl.alternateField", new String[] { CollectionSchema.description_txt.getSolrFieldName() }); if (!mmsp.getMap().containsKey("hl.simple.pre")) mmsp.getMap().put("hl.simple.pre", new String[] { "<b>" }); if (!mmsp.getMap().containsKey("hl.simple.post")) mmsp.getMap().put("hl.simple.post", new String[] { "</b>" }); if (!mmsp.getMap().containsKey("hl.fragsize")) mmsp.getMap().put("hl.fragsize", new String[] { Integer.toString(SearchEvent.SNIPPET_MAX_LENGTH) }); if (!mmsp.getMap().containsKey("fl")) mmsp.getMap().put("fl", new String[] { CollectionSchema.sku.getSolrFieldName() + "," + CollectionSchema.title + "," + CollectionSchema.description_txt.getSolrFieldName() + "," + CollectionSchema.id.getSolrFieldName() + "," + CollectionSchema.url_paths_sxt.getSolrFieldName() + "," + CollectionSchema.last_modified.getSolrFieldName() + "," + CollectionSchema.size_i.getSolrFieldName() + "," + CollectionSchema.url_protocol_s.getSolrFieldName() + "," + CollectionSchema.url_file_ext_s.getSolrFieldName() }); } // get the embedded connector String requestURI = hrequest.getRequestURI(); boolean defaultConnector = (requestURI.startsWith("/solr/" + WebgraphSchema.CORE_NAME)) ? false : requestURI.startsWith("/solr/" + CollectionSchema.CORE_NAME) || mmsp.get("core", CollectionSchema.CORE_NAME).equals(CollectionSchema.CORE_NAME); mmsp.getMap().remove("core"); SolrConnector connector = defaultConnector ? sb.index.fulltext().getDefaultEmbeddedConnector() : sb.index.fulltext().getEmbeddedConnector(WebgraphSchema.CORE_NAME); if (connector == null) { connector = defaultConnector ? sb.index.fulltext().getDefaultConnector() : sb.index.fulltext().getConnectorForRead(WebgraphSchema.CORE_NAME); } if (connector == null) throw new ServletException("no core"); // add default queryfield parameter according to local ranking config (or defaultfield) if (ranking != null) { // ranking normally never null final String qf = ranking.getQueryFields(); if (qf.length() > 4) { // make sure qf has content (else use df) addParam(DisMaxParams.QF, qf, mmsp.getMap()); // add QF that we set to be best suited for our index // TODO: if every peer applies a decent QF itself, this can be reverted to getMap().put() } else { mmsp.getMap().put(CommonParams.DF, new String[] { CollectionSchema.text_t.getSolrFieldName() }); } } else { mmsp.getMap().put(CommonParams.DF, new String[] { CollectionSchema.text_t.getSolrFieldName() }); } // do the solr request, generate facets if we use a special YaCy format final SolrQueryResponse rsp; if (connector instanceof EmbeddedSolrConnector) { req = ((EmbeddedSolrConnector) connector).request(mmsp); rsp = ((EmbeddedSolrConnector) connector).query(req); // prepare response hresponse.setHeader("Cache-Control", "no-cache, no-store"); HttpCacheHeaderUtil.checkHttpCachingVeto(rsp, hresponse, reqMethod); // check error if (rsp.getException() != null) { AccessTracker.addToDump(querystring, "0", new Date()); sendError(hresponse, rsp.getException()); return; } NamedList<?> values = rsp.getValues(); DocList r = ((ResultContext) values.get("response")).docs; int numFound = r.matches(); AccessTracker.addToDump(querystring, Integer.toString(numFound), new Date()); // write response header final String contentType = responseWriter.getContentType(req, rsp); if (null != contentType) response.setContentType(contentType); if (Method.HEAD == reqMethod) { return; } // write response body if (responseWriter instanceof BinaryResponseWriter) { ((BinaryResponseWriter) responseWriter).write(response.getOutputStream(), req, rsp); } else { out = new FastWriter( new OutputStreamWriter(response.getOutputStream(), StandardCharsets.UTF_8)); responseWriter.write(out, req, rsp); out.flush(); } } else { // write a 'faked' response using a call to the backend SolrDocumentList sdl = connector.getDocumentListByQuery(mmsp.getMap().get(CommonParams.Q)[0], mmsp.getMap().get(CommonParams.SORT) == null ? null : mmsp.getMap().get(CommonParams.SORT)[0], Integer.parseInt(mmsp.getMap().get(CommonParams.START)[0]), Integer.parseInt(mmsp.getMap().get(CommonParams.ROWS)[0]), mmsp.getMap().get(CommonParams.FL)); OutputStreamWriter osw = new OutputStreamWriter(response.getOutputStream()); EnhancedXMLResponseWriter.write(osw, req, sdl); osw.close(); } } catch (final Throwable ex) { sendError(hresponse, ex); } finally { if (req != null) { req.close(); } SolrRequestInfo.clearRequestInfo(); if (out != null) try { out.close(); } catch (final IOException e1) { } } } private static void sendError(HttpServletResponse hresponse, Throwable ex) throws IOException { int code = (ex instanceof SolrException) ? ((SolrException) ex).code() : 500; StringWriter sw = new StringWriter(); ex.printStackTrace(new PrintWriter(sw)); hresponse.sendError((code < 100) ? 500 : code, ex.getMessage() + "\n\n" + sw.toString()); } public static void waitForSolr(String context, int port) throws Exception { // A raw term query type doesn't check the schema URL url = new URL("http://127.0.0.1:" + port + context + "/select?q={!raw+f=test_query}ping"); Exception ex = null; // Wait for a total of 20 seconds: 100 tries, 200 milliseconds each for (int i = 0; i < 600; i++) { try { InputStream stream = url.openStream(); stream.close(); } catch (final IOException e) { ex = e; Thread.sleep(200); continue; } return; } throw new RuntimeException("Jetty/Solr unresponsive", ex); } public static class Servlet404 extends HttpServlet { private static final long serialVersionUID = -4497069674942245148L; @Override public void service(HttpServletRequest req, HttpServletResponse res) throws IOException { res.sendError(404, "Can not find: " + req.getRequestURI()); } } }