Java tutorial
/* Copyright 2006 OCLC Online Computer Library Center, Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ /* * SRWRemoteDatabase.java * * Created on September 7, 2004, 4:24 PM */ package ORG.oclc.os.SRW.ParallelSearching; import ORG.oclc.os.SRW.QueryResult; import ORG.oclc.os.SRW.SRWDatabase; import ORG.oclc.os.SRW.SRWDiagnostic; import ORG.oclc.os.SRW.TermList; import ORG.oclc.os.SRW.Utilities; import gov.loc.www.zing.srw.ScanRequestType; import gov.loc.www.zing.srw.ScanResponseType; import gov.loc.www.zing.srw.SearchRetrieveRequestType; import java.io.BufferedReader; import java.io.CharConversionException; import java.io.EOFException; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URL; import java.util.Hashtable; import java.util.Properties; import javax.servlet.http.HttpServletRequest; import org.apache.axis.types.NonNegativeInteger; import org.apache.axis.types.PositiveInteger; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.z3950.zing.cql.CQLTermNode; //import ORG.oclc.ber.DataDir; /** * * @author levan */ public class SRWRemoteDatabase extends SRWDatabase { static Log log = LogFactory.getLog(SRWRemoteDatabase.class); String configInfo, indexInfo, url; public void addRenderer(String schemaName, String schemaID, Properties props) throws InstantiationException { } public TermList getTermList(CQLTermNode seedTerm, int position, int maxTerms, ScanRequestType request) { TermList tl = new TermList(); try { long startTime = System.currentTimeMillis(); String scanClause = request.getScanClause(); String urlStr = url + "&operation=scan&scanClause=" + Utilities.urlEncode(scanClause); NonNegativeInteger responsePosition = request.getResponsePosition(); if (responsePosition != null) urlStr = urlStr + "&responsePosition=" + responsePosition; PositiveInteger maximumTerms = request.getMaximumTerms(); if (maximumTerms != null) urlStr = urlStr + "&maximumTerms=" + maximumTerms; log.info("urlStr=" + urlStr); ScanResponseType srt = (ScanResponseType) Utilities.xmlToObj(getRemoteResponse(urlStr)); log.info("scan " + scanClause + ": " + (System.currentTimeMillis() - startTime) + "ms"); tl.setTerms(srt.getTerms().getTerm()); return tl; } catch (Exception e) { log.error(e, e); tl.addDiagnostic(SRWDiagnostic.newDiagnosticType(SRWDiagnostic.QuerySyntaxError, e.getMessage())); return tl; } } public String getConfigInfo() { return configInfo; } public String getIndexInfo() { return indexInfo; } public String getExtraResponseData(QueryResult result, SearchRetrieveRequestType request) { return null; } public static String getRemoteResponse(String urlStr) throws CharConversionException, EOFException, IOException { URL u; u = new URL(urlStr); log.info("before searchHandler.Input" + "; " + System.currentTimeMillis()); InputStream is = null; int errorCount = 0; IOException lastException = null; while (is == null && errorCount < 100) { try { is = u.openStream(); } catch (IOException e) { lastException = e; log.error(e, e); errorCount++; u = new URL(urlStr); } } if (is == null) throw lastException; BufferedReader in = new BufferedReader(new InputStreamReader(is)); String inputLine = null; StringBuffer content = new StringBuffer(); try { while ((inputLine = in.readLine()) != null) content.append(inputLine); } catch (java.io.IOException e) { log.error(e, e); return null; } String response = content.toString(); log.debug(response); log.info("after searchHandler.Input" + "; " + System.currentTimeMillis()); return response; } public QueryResult getQueryResult(String query, SearchRetrieveRequestType request) throws InstantiationException { long startTime = System.currentTimeMillis(); String urlStr = url + "&operation=searchRetrieve&query=" + Utilities.urlParameterEncode(query); NonNegativeInteger maxRecords = request.getMaximumRecords(); if (maxRecords != null) urlStr = urlStr + "&maximumRecords=" + maxRecords; NonNegativeInteger startRecord = request.getStartRecord(); if (startRecord != null) urlStr = urlStr + "&startRecord=" + startRecord; String schema = request.getRecordSchema(); if (schema != null) urlStr = urlStr + "&recordSchema=" + schema; NonNegativeInteger resultSetTTL = request.getResultSetTTL(); if (resultSetTTL != null) urlStr = urlStr + "&resultSetTTL=" + resultSetTTL; String sortKeys = request.getSortKeys(); if (sortKeys != null) urlStr = urlStr + "&sortKeys=" + Utilities.urlParameterEncode(sortKeys); Hashtable extraRequestDataElements = parseElements(request.getExtraRequestData()); String s = (String) extraRequestDataElements.get("restrictorSummary"); if (s != null && !s.equals("false")) { // restrictorSummary=true; urlStr = urlStr + "&x-info-5-restrictorSummary"; log.info("turned restrictorSummary on"); } s = (String) extraRequestDataElements.get("returnSortKeys"); if (s != null && !s.equals("false")) { // returnSortKeys=true; urlStr = urlStr + "&x-info-5-returnSortKeys"; log.info("turned returnSortKeys on"); } log.info("urlStr=" + urlStr + "; " + System.currentTimeMillis()); try { RemoteQueryResult rqr = new RemoteQueryResult(url, getRemoteResponse(urlStr)); log.info("search " + query + ": " + (System.currentTimeMillis() - startTime) + "ms"); return rqr; } catch (CharConversionException e) { log.error(e, e); throw new InstantiationException(e.getMessage()); } catch (EOFException e) { log.error(e, e); throw new InstantiationException(e.getMessage()); } catch (IOException e) { log.error(e, e); throw new InstantiationException(e.getMessage()); } // if(recordPacking==null) { // MessageContext msgContext=MessageContext.getCurrentContext(); // if(msgContext!=null && msgContext.getProperty("sru")!=null) // recordPacking="xml"; // default for sru // else // recordPacking="string"; // default for srw // } // log.info("calling getNextSearchRetrieveResponse"+"; "+System.currentTimeMillis()); // SearchRetrieveResponseType response=searchHandler.getNextSearchRetrieveResponse(recordPacking); // log.info("exit doRequest"+"; "+System.currentTimeMillis()); // return response; } public void init(String dbname, String srwHome, String dbHome, String dbPropertiesFileName, Properties dbProperties, HttpServletRequest request) throws java.net.MalformedURLException { log.debug("entering SRWRemoteDatabase.init, dbname=" + dbname); initDB(dbname, srwHome, dbHome, dbPropertiesFileName, dbProperties); String baseUrl = dbProperties.getProperty("remoteURL"); url = baseUrl + "?version=1.1"; try { URL explainURL = new URL(baseUrl); log.info("baseUrl=" + baseUrl); BufferedReader in = new BufferedReader(new InputStreamReader(explainURL.openStream())); log.debug("got an explain response from the remote database!"); String inputLine; StringBuffer explainResponse = new StringBuffer(); for (int i = 0; (inputLine = in.readLine()) != null; i++) explainResponse.append(inputLine).append('\n'); in.close(); if (log.isDebugEnabled()) log.debug(explainResponse); String explain = explainResponse.toString(); int start = explain.indexOf("<indexInfo"); int stop = explain.indexOf("</indexInfo>") + 12; indexInfo = explain.substring(start, stop); start = explain.indexOf("<schemaInfo"); stop = explain.indexOf("</schemaInfo>") + 13; schemaInfo = explain.substring(start, stop); useSchemaInfo(schemaInfo); start = explain.indexOf("<configInfo"); stop = explain.indexOf("</configInfo>") + 13; configInfo = explain.substring(start, stop); useConfigInfo(getConfigInfo()); } catch (Exception e) { log.error(e, e); } } public boolean supportsSort() { return true; } }