Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. */ package org.apache.nutch.webapp.common; import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.io.Writable; import org.apache.nutch.html.Entities; import org.apache.nutch.searcher.Hit; import org.apache.nutch.searcher.HitDetails; import org.apache.nutch.searcher.Hits; import org.apache.nutch.searcher.Query; import org.apache.nutch.searcher.Summary; /** * Search is a bean that represents an ongoing search. * * After search searchBean that represents the search user doing (also the * results) might be a good candidate for caching ? * */ public class Search implements Writable { private static final long serialVersionUID = 1L; public static final String REQ_ATTR_SEARCH = "nutchSearch"; public static final Log LOG = LogFactory.getLog(Search.class); String queryString; String htmlQueryString; Query query; int startOffset; int hitsPerDup; // Number of results per page int hitsPerPage; // Number of hits required, for example clustering plugin might require more // than hitsPerPage hits int hitsRequired = 0; String sortColumn; boolean sortDesc; Hits hits; Hit[] show; HitDetails[] details; Summary[] summaries; ArrayList results = null; NavigationHelper navigationHelper; ServiceLocator locator; SearchForm form; String dupField; /** * Perform search described by this bean * * @param bean */ public void performSearch() { LOG.info("performing search, requiring:" + getHitsRequired()); try { LOG.info("query:" + getQuery()); LOG.info("endOffset:" + getStartOffset() + getHitsRequired()); LOG.info("hitsPerDup:" + getHitsPerDup()); LOG.info("dupField:" + getDupField()); LOG.info("sortField:" + getSortColumn()); LOG.info("descending:" + isSortDesc()); hits = locator.getNutchBean().search(getQuery(), getStartOffset() + getHitsRequired(), getHitsPerDup(), getDupField(), getSortColumn(), isSortDesc()); } catch (IOException e) { hits = new Hits(0, new Hit[0]); } int realEnd = (int) Math.min(hits.getLength(), getStartOffset() + getHitsRequired()); init(); show = hits.getHits(getStartOffset(), realEnd - getStartOffset()); try { details = locator.getNutchBean().getDetails(show); summaries = locator.getNutchBean().getSummary(details, getQuery()); } catch (IOException e) { LOG.info("Error getting hit information:" + e); e.printStackTrace(); } } public void init() { int endOffset = hits.getLength(); navigationHelper = new NavigationHelper(startOffset, endOffset, hitsPerPage, hits.getTotal(), hits.totalIsExact()); // set offset to next page to form so it get's to ui if (navigationHelper.hasNext()) { form.setValue(SearchForm.NAME_START, Long.toString(navigationHelper.getNextPageStart())); } } /** * Gets the results of search to display. * * @return */ public List getResults() { int len = Math.min(details.length, getHitsPerPage()); if (results == null) { results = new ArrayList(len); for (int i = 0; i < len; i++) { results.add(new SearchResultBean(this, show[i], details[i], summaries[i])); } } return results; } protected int parseInt(String value, int defaultValue) { int ret = defaultValue; if (value != null) { try { ret = Integer.parseInt(value); } catch (Exception e) { // ignore } } return ret; } public Search() { } public Search(ServiceLocator locator) { this.locator = locator; Preferences prefs = locator.getPreferences(); form = locator.getSearchForm(); queryString = form.getValueString(SearchForm.NAME_QUERYSTRING); if (queryString == null) { queryString = ""; } htmlQueryString = Entities.encode(queryString); startOffset = parseInt(form.getValueString(SearchForm.NAME_START), 0); hitsPerPage = parseInt(form.getValueString(SearchForm.NAME_HITSPERPAGE), prefs.getInt(Preferences.KEY_RESULTS_PER_PAGE, 10)); hitsPerDup = parseInt(form.getValueString(SearchForm.NAME_HITSPERDUP), prefs.getInt(Preferences.KEY_HITS_PER_DUP, 2)); sortColumn = form.getValueString(SearchForm.NAME_SORTCOLUMN); sortDesc = (sortColumn != null && "true".equals(form.getValueString(SearchForm.NAME_SORTREVERSE))); dupField = form.getValueString(SearchForm.NAME_DUPCOLUMN); if (dupField == null) { dupField = "site"; } try { query = Query.parse(queryString, locator.getConfiguration()); } catch (IOException e) { LOG.info("Error parsing query:" + e); e.printStackTrace(); } } /** * @return Returns the hitsPerPage. */ public int getHitsPerPage() { return hitsPerPage; } /** * @param hitsPerPage * The hitsPerPage to set. */ protected void setHitsPerPage(int hitsPerPage) { this.hitsPerPage = hitsPerPage; } /** * @return Returns the hitsPerSite. */ public int getHitsPerDup() { return hitsPerDup; } /** * @param hitsPerSite * The hitsPerSite to set. */ protected void setHitsPerSite(int hitsPerSite) { this.hitsPerDup = hitsPerSite; } /** * @return Returns the query. */ public Query getQuery() { return query; } /** * @param query * The query to set. */ public void setQuery(Query query) { this.query = query; } /** * @return Returns the queryString. */ public String getQueryString() { return queryString; } /** * @param queryString * The queryString to set. */ protected void setQueryString(String queryString) { this.queryString = queryString; } /** * Returns true if sort is descending. * * @return Returns sort order */ public boolean isSortDesc() { return sortDesc; } /** * Set sort order. * * @param sortAsc * The sortAsc to set. */ protected void setSortDesc(boolean sortAsc) { this.sortDesc = sortAsc; } /** * @return Returns the sortColumn. */ public String getSortColumn() { return sortColumn; } /** * @param sortColumn * The sortColumn to set. */ protected void setSortColumn(String sortColumn) { this.sortColumn = sortColumn; } /** * @return Returns the startOffset. */ public int getStartOffset() { return startOffset; } /** * @param startOffset * The startOffset to set. */ protected void setStartOffset(int startOffset) { this.startOffset = startOffset; } /** * @return Returns the htmlQueryString. */ public String getHtmlQueryString() { return htmlQueryString; } /** * @param htmlQueryString * The htmlQueryString to set. */ protected void setHtmlQueryString(String htmlQueryString) { this.htmlQueryString = htmlQueryString; } /** * @return Returns the details. */ public HitDetails[] getDetails() { return details; } /** * @param details * The details to set. */ protected void setDetails(HitDetails[] details) { this.details = details; } /** * @return Returns the hits. */ public Hits getHits() { return hits; } /** * @param hits * The hits to set. */ protected void setHits(Hits hits) { this.hits = hits; } /** * @return Returns the show. */ public Hit[] getShow() { return show; } /** * @param show * The show to set. */ protected void setShow(Hit[] show) { this.show = show; } /** * @return Returns the summaries. */ public Summary[] getSummaries() { return summaries; } /** * @param summaries * The summaries to set. */ protected void setSummaries(Summary[] summaries) { this.summaries = summaries; } /** * returns start, end, total, used for printing message on search page, this * is why offset is +1'd. */ public String[] getResultInfo() { return new String[] { Long.toString(startOffset + 1), Long.toString(navigationHelper.getEnd()), Long.toString(hits.getTotal()), getHtmlQueryString() }; } /** * @return true if more results available */ public boolean getHasNextPage() { return navigationHelper.hasNext(); } /** * @return true if previous page if available */ public boolean getHasPrevPage() { return navigationHelper.hasPrev(); } public String getDupField() { return dupField; } protected SearchForm getForm() { return form; } /** * @return */ public List getFormProperties() { return form.getActive(); } public boolean getShowAllHits() { if (navigationHelper.getShowAllHits()) { //remove start parameter from form getForm().remove(SearchForm.NAME_START); //add hitsPerDup=0 getForm().setValue(SearchForm.NAME_HITSPERDUP, "0"); } return navigationHelper.getShowAllHits(); } /** * Return true if there are results. * * @return */ public boolean getHasResults() { return hits.getTotal() > 0; } public boolean getIsSearch() { return queryString != null && !queryString.trim().equals(""); } /** * Return number of hits required, if not specified defaults to HitsPerPage. * @return */ public int getHitsRequired() { if (hitsRequired != 0) { return hitsRequired; } return getHitsPerPage(); } /** * Set number of hits required. * @param hitsRequired */ public void setHitsRequired(int hitsRequired) { this.hitsRequired = hitsRequired; } /** * Launch search. */ public void launchSearch() { BaseSearch bs = new BaseSearch(locator); bs.doSearch(); } public void write(DataOutput out) throws IOException { LOG.info("writing hits"); hits.write(out); out.writeInt(show.length); for (int i = 0; i < show.length; i++) { show[i].write(out); } out.writeInt(details.length); for (int i = 0; i < details.length; i++) { details[i].write(out); } out.writeInt(summaries.length); for (int i = 0; i < summaries.length; i++) { summaries[i].write(out); } } public void readFields(DataInput in) throws IOException { hits = new Hits(); hits.readFields(in); int showlength = in.readInt(); show = new Hit[showlength]; for (int i = 0; i < showlength; i++) { show[i] = new Hit(); show[i].readFields(in); } int detailsLength = in.readInt(); details = new HitDetails[detailsLength]; for (int i = 0; i < detailsLength; i++) { details[i] = new HitDetails(); details[i].readFields(in); } int summariesLength = in.readInt(); summaries = new Summary[summariesLength]; for (int i = 0; i < summariesLength; i++) { summaries[i] = new Summary(); summaries[i].readFields(in); } } }