一、先摆需求：
1、中文搜索、英文搜索、中英混搜 如：“南京东路”，“cafe 南京东路店”
2、全拼搜索、首字母搜索、中文+全拼、中文+首字母混搜 如：“nanjingdonglu”，“njdl”，“南京donglu”，“南京dl”，“nang南东路”，“njd路”等等组合
3、简繁搜索、特殊符号过滤搜索 如：“龍馬”可通过“龙马”搜索，再比如 L.G.F可以通过lgf搜索，café可能通过cafe搜索
4、排序优先级为： 以关键字开头>包含关键字
二、生产效果图：
三、实现
1、索引设计
使用multi_field为搜索字段建立不同类型的索引，有全拼索引、首字母简写索引、Ngram索引以及IK索引，从各个角度分别击破，然后通过char-filter进行特殊符号与简繁转换。
curl -XPUT localhost:9200/search_words_index -d '{
"settings" : {
"refresh_interval" : "5s",
"number_of_shards" : 1,
"number_of_replicas" : 1,
"analysis" : {
"filter": {
"edge_ngram_filter": {
"type": "edge_ngram",
"min_gram": 1,
"max_gram": 50
},
"pinyin_simple_filter":{
"type" : "pinyin",
"keep_first_letter":true,
"keep_separate_first_letter" : false,
"keep_full_pinyin" : false,
"keep_original" : false,
"limit_first_letter_length" : 50,
"lowercase" : true
},
"pinyin_full_filter":{
"type" : "pinyin",
"keep_first_letter":false,
"keep_separate_first_letter" : false,
"keep_full_pinyin" : true,
"none_chinese_pinyin_tokenize":true,
"keep_original" : false,
"limit_first_letter_length" : 50,
"lowercase" : true
},
"t2s_convert":{
"type": "stconvert",
"delimiter": ",",
"convert_type": "t2s"
}
},
"char_filter" : {
"charconvert" : {
"type" : "mapping",
"mappings_path":"char_filter_text.txt"
}
},
"tokenizer":{
"ik_smart":{
"type":"ik",
"use_smart":true
}
},
"analyzer": {
"ngramIndexAnalyzer": {
"type": "custom",
"tokenizer": "keyword",
"filter": ["edge_ngram_filter","lowercase"],
"char_filter" : ["charconvert"]
},
"ngramSearchAnalyzer": {
"type": "custom",
"tokenizer": "keyword",
"filter":["lowercase"],
"char_filter" : ["charconvert"]
},
"ikIndexAnalyzer": {
"type": "custom",
"tokenizer": "ik",
"char_filter" : ["charconvert"]
},
"ikSearchAnalyzer": {
"type": "custom",
"tokenizer": "ik",
"char_filter" : ["charconvert"]
},
"pinyiSimpleIndexAnalyzer":{
"tokenizer" : "keyword",
"filter": ["pinyin_simple_filter","edge_ngram_filter","lowercase"]
},
"pinyiSimpleSearchAnalyzer":{
"tokenizer" : "keyword",
"filter": ["pinyin_simple_filter","lowercase"]
},
"pinyiFullIndexAnalyzer":{
"tokenizer" : "keyword",
"filter": ["pinyin_full_filter","lowercase"]
},
"pinyiFullSearchAnalyzer":{
"tokenizer" : "keyword",
"filter": ["pinyin_full_filter","lowercase"]
}
}
}
},
"mappings": {
"search_words_type": {
"properties": {
"words": {
"type": "multi_field",
"fields":{
"words": {
"type": "string",
"index": "analyzed",
"indexAnalyzer" : "ngramIndexAnalyzer"
},
"SPY": {
"type": "string",
"index": "analyzed",
"indexAnalyzer" : "pinyiSimpleIndexAnalyzer"
},
"FPY": {
"type": "string",
"index": "analyzed",
"indexAnalyzer" : "pinyiFullIndexAnalyzer"
},
"IKS": {
"type": "string",
"index": "analyzed",
"indexAnalyzer" : "ikIndexAnalyzer"
}
}
}
}
}
}
}'
拼音插件的使用请参考：https://github.com/medcl/elasticsearch-analysis-pinyin
2、搜索构建
以下是搜索实现代码（非完整代码，只摘录核心部分，主要是思路）：
/**
* 纯中文搜索
* @return
*/
public List<Map> chineseSearch(String key,Integer cityId) throws Exception{
DisMaxQueryBuilder disMaxQueryBuilder=QueryBuilders.disMaxQuery();
//以关键字开头(优先级最高)
MatchQueryBuilder q1=QueryBuilders.matchQuery("words",key).analyzer("ngramSearchAnalyzer").boost(5);
//完整包含经过分析过的关键字
// boolean whitespace=key.contains(" ");
// int slop=whitespace?50:5;
QueryBuilder q2=QueryBuilders.matchQuery("words.IKS", key).analyzer("ikSearchAnalyzer").minimumShouldMatch("100%");
disMaxQueryBuilder.add(q1);
disMaxQueryBuilder.add(q2);
SearchQuery searchQuery=builderQuery(cityId,disMaxQueryBuilder);
return elasticsearchTemplate.queryForList(searchQuery,Map.class);
} /**
* 混合搜索
* @return
*/
public List<Map> chineseWithEnglishOrPinyinSearch(String key,Integer cityId) throws Exception{ DisMaxQueryBuilder disMaxQueryBuilder=QueryBuilders.disMaxQuery();
//是否有中文开头，有则返回中文前缀
String startChineseString=commonSearchService.getStartChineseString(key);
/**
* 源值搜索，不做拼音转换
* 权重* 1.5
*/
QueryBuilder normSearchBuilder=QueryBuilders.matchQuery("words",key).analyzer("ngramSearchAnalyzer").boost(5f); /**
* 拼音简写搜索
* 1、分析key，转换为简写 case: 南京东路==>njdl，南京dl==>njdl，njdl==>njdl
* 2、搜索匹配，必须完整匹配简写词干
* 3、如果有中文前缀，则排序优先
* 权重*1
*/
String analysisKey=commonSearchService.anaysisKeyAndGetMaxWords(SearchIndex.INDEX_NAME_SEARCHWORDSSTATISTICS,key,"pinyiSimpleSearchAnalyzer");
QueryBuilder pingYinSampleQueryBuilder=QueryBuilders.termQuery("words.SPY", analysisKey); /**
* 拼音简写包含匹配，如 njdl可以查出 "城市公牛 南京东路店"，虽然非南京东路开头
* 权重*0.8
*/
QueryBuilder pingYinSampleContainQueryBuilder=null;
if(analysisKey.length()>1){
pingYinSampleContainQueryBuilder=QueryBuilders.wildcardQuery("words.SPY", "*"+analysisKey+"*").boost(0.8f);
} /**
* 拼音全拼搜索
* 1、分析key，获取拼音词干 case : 南京东路==>[nan,jing,dong,lu]，南京donglu==>[nan,jing,dong,lu]
* 2、搜索查询，必须匹配所有拼音词，如南京东路，则nan,jing,dong,lu四个词干必须完全匹配
* 3、如果有中文前缀，则排序优先
* 权重*1
*/
QueryBuilder pingYinFullQueryBuilder=null;
if(key.length()>1){
pingYinFullQueryBuilder=QueryBuilders.matchPhraseQuery("words.FPY", key).analyzer("pinyiFullSearchAnalyzer");
} /**
* 完整包含关键字查询(优先级最低，只有以上四种方式查询无结果时才考虑）
* 权重*0.8
*/
QueryBuilder containSearchBuilder=QueryBuilders.matchQuery("words.IKS", key).analyzer("ikSearchAnalyzer").minimumShouldMatch("100%"); disMaxQueryBuilder
.add(normSearchBuilder)
.add(pingYinSampleQueryBuilder)
.add(containSearchBuilder); //以下两个对性能有一定的影响，故作此判定，单个字符不执行此类搜索
if(pingYinFullQueryBuilder!=null){
disMaxQueryBuilder.add(pingYinFullQueryBuilder);
}
if(pingYinSampleContainQueryBuilder!=null){
disMaxQueryBuilder.add(pingYinSampleContainQueryBuilder);
} QueryBuilder queryBuilder=disMaxQueryBuilder; //关键如果有中文，则必须包含在内容中
if(StringUtils.isNotBlank(startChineseString)){
queryBuilder= QueryBuilders.filteredQuery(disMaxQueryBuilder,
FilterBuilders.queryFilter(QueryBuilders.queryStringQuery("*"+startChineseString+"*").field("words").analyzer("ngramSearchAnalyzer")));
queryBuilder=QueryBuilders.functionScoreQuery(queryBuilder)
.add(FilterBuilders.queryFilter(QueryBuilders.matchQuery("words",startChineseString).analyzer("ngramSearchAnalyzer")), ScoreFunctionBuilders.weightFactorFunction(1.5f));
} SearchQuery searchQuery=builderQuery(cityId,queryBuilder); return elasticsearchTemplate.queryForList(searchQuery,Map.class);
}
注：以上JAVA示例代码皆以spring-data-elasticsearch框架为基础。
拼音插件安装：
1、下载拼音插件，官网地址：https://github.com/medcl/elasticsearch-analysis-pinyin 我下载的版本是：elasticsearch-analysis-pinyin-1.3.3。
把下载的 elasticsearch-analysis-pinyin-1.3.3.jar与nlp-lang-1.7.jar放于plugins目录下。
2、修改elasticsearch配置文件，在最后一行之下加入（里面包括IK配置，如果未安装IK可省略IK的配置）：
index:
analysis:
analyzer:
ik:
alias: [news_analyzer_ik,ik_analyzer]
type: org.elasticsearch.index.analysis.IkAnalyzerProvider
ik_max_word:
type: ik
use_smart: false
ik_smart:
type: ik
use_smart: true
pinyin:
tokenizer: pinyin_tokenizer
filter: [standard,nGram]
tokenizer:
pinyin_tokenizer:
type: pinyin
first_letter: "prefix"
padding_char: ""
3、定制特殊符号及简繁转换文本：char_filter_text.txt，由于文件有点长，以下是部分内容，参考格式即可。
à=>a
á=>a
â=>a
ä=>a
À=>a
Â=>a
Ä=>a
è=>e
é=>e
ê=>e
ë=>e
È=>e
É=>e
Ê=>e
Ë=>e
î=>i
ï=>i
Î=>i
Ï=>i
ô=>o
ö=>o
Ô=>o
Ö=>o
ù=>u
û=>u
ü=>u
Ù=>u
Û=>u
Ü=>u
ç=>c
œ=>c
&=>
^=>
.=>
·=>
-=>
'=>
’=>
‘=>
/=>
醯壶=>醯壶
屢顧爾僕=>屡顾尔仆
見=>见
往裡=>往里
置言成範=>置言成范
捲動=>卷动
規=>规
齣電視=>出电视
覎=>觃
後堂=>后堂
4、重启elasticsearch，重建索引，看是否生效。