Solr实现Low Level查询解析（QParser）第2页_服务器应用

首先，和前端设计定义统一的接口：

北京OR北平OR首都OR京城OR京都AND首都博物馆OR首博 <=> +((title:北京 content:北京) (title:北平 content:北平) (title:首都 content:首都) (title:京城 content:京城) (title:京都 content:京都)) +((title:首都博物馆 content:首都博物馆) (title:首博 content:首博))

我们通过在扩展的QParser中进行解析，代码如下所示：

package org.shirdrn.solr.search;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.DisjunctionMaxQuery;
import org.apache.lucene.search.PhraseQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.common.params.DefaultSolrParams;
import org.apache.solr.common.params.DisMaxParams;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.search.DisMaxQParser;
import org.apache.solr.util.SolrPluginUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Customized solr QParser of the plugin
*
* @author shirdrn 2011/11/03
*/
public class SimpleQParser extends DisMaxQParser {
private final Logger LOG = LoggerFactory.getLogger(SimpleQParser.class);
// using low level Term query? For internal search usage.
private boolean useLowLevelTermQuery = false;
private float tiebreaker = 0f;
private static Float mainBoost = 1.0f;
private static Float frontBoost = 1.0f;
private static Float rearBoost = 1.0f;
private String userQuery = "";
public SimpleQParser(String qstr, SolrParams localParams,
SolrParams params, SolrQueryRequest req) {
super(qstr, localParams, params, req);
}
@Override
public Query parse() throws ParseException {
SolrParams solrParams = localParams == null ? params : new DefaultSolrParams(localParams, params);
queryFields = SolrPluginUtils.parseFieldBoosts(solrParams.getParams(DisMaxParams.QF));
if (0 == queryFields.size()) {
queryFields.put(req.getSchema().getDefaultSearchFieldName(), 1.0f);
}
/* the main query we will execute. we disable the coord because
* this query is an artificial construct
*/
BooleanQuery query = new BooleanQuery(true);
addMainQuery(query, solrParams);
// rewrite q parameter for highlighting
if(useLowLevelTermQuery) {
query = new BooleanQuery(true);
rewriteAndOrQuery(userQuery, query, solrParams);
}
addBoostQuery(query, solrParams);
addBoostFunctions(query, solrParams);
return query;
}
protected void addMainQuery(BooleanQuery query, SolrParams solrParams)throws ParseException {
tiebreaker = solrParams.getFloat(DisMaxParams.TIE, 0.0f);
// get the comma separated list of fields used for payload
/*
* a parser for dealing with user input, which will convert things to
* DisjunctionMaxQueries
*/
SolrPluginUtils.DisjunctionMaxQueryParser up = getParser(queryFields,DisMaxParams.QS, solrParams, tiebreaker);
/* * * Main User Query * * */
parsedUserQuery = null;
userQuery = getString();
altUserQuery = null;
if (userQuery == null || userQuery.trim().length() < 1) {
// If no query is specified, we may have an alternate
altUserQuery = getAlternateUserQuery(solrParams);
query.add(altUserQuery, BooleanClause.Occur.MUST);
} else {
// There is a valid query string
userQuery = SolrPluginUtils.partialEscape(SolrPluginUtils.stripUnbalancedQuotes(userQuery)).toString();
userQuery = SolrPluginUtils.stripIllegalOperators(userQuery).toString();
// use low level Term for constructing TermQuery or BooleanQuery.
// warning: for internal AND, OR query, in order to integrate with Solr for obtaining highlight
String luceneQueryText = userQuery;
String q = solrParams.get(CommonParams.Q);
if(q!=null && (q.indexOf("AND")!=-1 || q.indexOf("OR")!=-1)) {
addBasicAndOrQuery(luceneQueryText, query, solrParams);
luceneQueryText = query.toString();
useLowLevelTermQuery = true;
}
LOG.debug("userQuery=" + luceneQueryText);
parsedUserQuery = getUserQuery(luceneQueryText, up, solrParams);
BooleanQuery rewritedQuery = rewriteQueries(parsedUserQuery);
query.add(rewritedQuery, BooleanClause.Occur.MUST);
}
}
protected void rewriteAndOrQuery(String userQuery, BooleanQuery query, SolrParams solrParams)throws ParseException {
addBasicAndOrQuery(userQuery, query, solrParams);
}
/**
* Parse mixing MUST and SHOULD query defined by us,
* e.g. 首都OR北京OR北平AND首博OR首都博物馆
* @param userQuery
* @param query
* @param solrParams
* @throws ParseException
*/
protected void addBasicAndOrQuery(String userQuery, BooleanQuery query, SolrParams solrParams)throws ParseException {
userQuery = SolrPluginUtils.partialEscape(SolrPluginUtils.stripUnbalancedQuotes(userQuery)).toString();
userQuery = SolrPluginUtils.stripIllegalOperators(userQuery).toString();
LOG.debug("userQuery=" + userQuery);
BooleanQuery parsedUserQuery = new BooleanQuery(true);
String[] a = userQuery.split("\\s*AND\\s*");
String q = "";
if(a.length==0) {
createTermQuery(parsedUserQuery, userQuery);
} if(a.length>=3) {
if(userQuery.indexOf("OR")==-1) { // e.g. 首都AND北京AND北平
BooleanQuery andBooleanQuery = parseAndQuery(a);
parsedUserQuery.add(andBooleanQuery, BooleanClause.Occur.MUST);
}
} else{
if(a.length>0) {
q = a[0].trim();
if(q.indexOf("OR")!=-1 || q.length()>0) {
parsedUserQuery.add(parseOrQuery(q, frontBoost), BooleanClause.Occur.MUST);
}
}
if(a.length==2) {
q = a[1].trim();
if(q.indexOf("OR")!=-1 || q.length()>0) {
parsedUserQuery.add(parseOrQuery(q, rearBoost), BooleanClause.Occur.MUST);
}
}
}
parsedUserQuery.setBoost(mainBoost);
BooleanQuery rewritedQuery = rewriteQueries(parsedUserQuery);
query.add(rewritedQuery, BooleanClause.Occur.MUST);
}
/**
* Parse SHOULD query, e.g. 北京OR北平OR首都
* @param ors
* @param boost
* @return
*/
private BooleanQuery parseOrQuery(String ors, Float boost) {
BooleanQuery bq = new BooleanQuery(true);
for(String or : ors.split("\\s*OR\\s*")) {
if(!or.isEmpty()) {
createTermQuery(bq, or.trim());
}
}
bq.setBoost(boost);
return bq;
}
/**
* Create TermQuery for some term text, query fields.
* @param bq
* @param qsr
*/
private void createTermQuery(BooleanQuery bq, String qsr) {
for(String field : queryFields.keySet()) {
TermQuery tq = new TermQuery(new Term(field, qsr));
if(queryFields.get(field)!=null) {
tq.setBoost(queryFields.get(field));
}
bq.add(tq, BooleanClause.Occur.SHOULD);
}
}
/**
* Parse MUST query, e.g. 首都AND北京AND北平
* @param ands
* @return
*/
private BooleanQuery parseAndQuery(String[] ands) {
BooleanQuery andBooleanQuery = new BooleanQuery(true);
for(String and : ands) {
if(!and.isEmpty()) {
BooleanQuery bq = new BooleanQuery(true);
createTermQuery(bq, and);
andBooleanQuery.add(bq, BooleanClause.Occur.MUST);
}
}
return andBooleanQuery;
}
/**
* Rewrite a query, especially a {@link BooleanQuery}, whose
* subclauses maybe include {@link BooleanQuery}s, {@link DisjunctionMaxQuery}s,
* {@link TermQuery}s, {@link PhraseQuery}s, {@link PayloadQuery}s, etc.
* @param input
* @return
*/
private BooleanQuery rewriteQueries(Query input) {
BooleanQuery output = new BooleanQuery(true);
if(input instanceof BooleanQuery) {
BooleanQuery bq = (BooleanQuery) input;
for(BooleanClause clause : bq.clauses()) {
if(clause.getQuery() instanceof DisjunctionMaxQuery) {
BooleanClause.Occur occur = clause.getOccur();
output.add(rewriteDisjunctionMaxQueries((DisjunctionMaxQuery) clause.getQuery()), occur); // BooleanClause.Occur.SHOULD
} else {
output.add(clause.getQuery(), clause.getOccur());
}
}
} else if(input instanceof DisjunctionMaxQuery) {
output.add(rewriteDisjunctionMaxQueries((DisjunctionMaxQuery) input), BooleanClause.Occur.SHOULD); // BooleanClause.Occur.SHOULD
}
output.setBoost(input.getBoost()); // boost main clause
return output;
}
/**
* Rewrite the {@link DisjunctionMaxQuery}, because of default parsing
* query string to {@link PhraseQuery}s which are not what we want.
* @param input
* @return
*/
private BooleanQuery rewriteDisjunctionMaxQueries(DisjunctionMaxQuery input) {
// input e.g. (content:"吉林长白山内蒙古九寨沟" | title:"吉林长白山内蒙古九寨沟"^1.5)~1.0
Map<String, BooleanQuery> m = new HashMap<String, BooleanQuery>();
Iterator<Query> iter = input.iterator();
while (iter.hasNext()) {
Query query = iter.next();
if(query instanceof PhraseQuery) {
PhraseQuery pq = (PhraseQuery) query; // e.g. content:"吉林长白山内蒙古九寨沟"
for(Term term : pq.getTerms()) {
BooleanQuery fieldsQuery = m.get(term.text());
if(fieldsQuery==null) {
fieldsQuery = new BooleanQuery(true);
m.put(term.text(), fieldsQuery);
}
fieldsQuery.setBoost(pq.getBoost());
fieldsQuery.add(new TermQuery(term), BooleanClause.Occur.SHOULD);
}
} else if(query instanceof TermQuery) {
TermQuery termQuery = (TermQuery) query;
BooleanQuery fieldsQuery = m.get(termQuery.getTerm().text());
if(fieldsQuery==null) {
fieldsQuery = new BooleanQuery(true);
m.put(termQuery.getTerm().text(), fieldsQuery);
}
fieldsQuery.setBoost(termQuery.getBoost());
fieldsQuery.add(termQuery, BooleanClause.Occur.SHOULD);
}
}
Iterator<Entry<String, BooleanQuery>> it = m.entrySet().iterator();
BooleanQuery mustBooleanQuery = new BooleanQuery(true);
while(it.hasNext()) {
Entry<String, BooleanQuery> entry = it.next();
BooleanQuery shouldBooleanQuery = new BooleanQuery(true);
createTermQuery(shouldBooleanQuery, entry.getKey());
mustBooleanQuery.add(shouldBooleanQuery, BooleanClause.Occur.MUST);
}
return mustBooleanQuery;
}
}