分散式搜尋Elasticsearch——QueryBuilders.matchPhrasePrefixQuery
阿新 • • 發佈:2019-02-11
ES源代碼中對matchPhrasePrefixQuery的描述如下所示:
/** * Creates a match query with type "PHRASE_PREFIX" for the provided field name and text. * * @param name The field name. * @param text The query text (to be analyzed). */ public static MatchQueryBuilder matchPhrasePrefixQuery(String name, Object text) { return new MatchQueryBuilder(name, text).type(MatchQueryBuilder.Type.PHRASE_PREFIX); }
如果你呼叫matchPhrasePrefixQuery時,text為中文,那麼,很大可能是一種狀況:你會發現,matchPhraseQuery和matchPhrasePrefixQuery沒有任何差別。而當text為英文時,差別就顯現出來了:matchPhraseQuery的text是一個英文單詞,而matchPhrasePrefixQuery的text則無這一約束,你可以從一個英文單詞中抽幾個連線在一起的字母進行查詢。
示例程式碼如下所示:
你會發現,使用matchPhraseQuery並未查詢出結果,而matchPhrasePrefixQuery查詢出的,則是我們需要的結果。/** * @author Geloin */ package com.gsoft.gsearch.util; import java.util.UUID; import junit.framework.Assert; import org.elasticsearch.action.bulk.BulkRequestBuilder; import org.elasticsearch.action.bulk.BulkResponse; import org.elasticsearch.action.index.IndexRequest; import org.elasticsearch.action.search.SearchResponse; import org.elasticsearch.index.query.QueryBuilder; import org.elasticsearch.index.query.QueryBuilders; import org.elasticsearch.search.SearchHit; import org.elasticsearch.search.SearchHits; import org.junit.Test; import com.gsoft.gsearch.BaseTest; import com.gsoft.gsearch.entity.Person; /** * 以短語形式查詢,查詢時關鍵字不會被分詞,而是直接以一個字串的形式查詢 * * @author Geloin * */ public class MatchPhrasePrefixQueryTest extends BaseTest { @Test public void matchPhrasePrefixQuery() { try { // 建立索引 BulkRequestBuilder builder = client.prepareBulk(); for (int i = 0; i < 2; i++) { Person p = new Person(); p.setId(UUID.randomUUID().toString()); p.setAge(20); p.setIsStudent(false); p.setSex("男"); p.setName("Zhangsan wang"); String source = ElasticSearchUtil.BeanToJson(p); IndexRequest request = client.prepareIndex().setIndex(index) .setType(type).setId(p.getId()).setSource(source) .request(); builder.add(request); } BulkResponse bResponse = builder.execute().actionGet(); if (bResponse.hasFailures()) { Assert.fail("建立索引出錯!"); } // 檢索 QueryBuilder qb = QueryBuilders.matchPhraseQuery("name", "wa"); SearchResponse searchResponse = client.prepareSearch(index) .setTypes(type).setQuery(qb).setFrom(0).setSize(12) .execute().actionGet(); SearchHits hits = searchResponse.getHits(); if (null == hits || hits.totalHits() == 0) { log.error("使用matchPhraseQuery(\"name\", \"wa
\")沒有查詢到任何結果!"); } else { for (SearchHit hit : hits) { String json = hit.getSourceAsString(); Person newPerson = mapper.readValue(json, Person.class); System.out.println("name\t\t" + newPerson.getName()); System.out.println("sex\t\t" + newPerson.getSex()); System.out.println("age\t\t" + newPerson.getAge()); System.out.println("isStudent\t\t" + newPerson.getIsStudent()); } } System.out.println("==================================================="); // 檢索 QueryBuilder qb1 = QueryBuilders.matchPhrasePrefixQuery("name", "wa"); SearchResponse searchResponse1 = client.prepareSearch(index) .setTypes(type).setQuery(qb1).setFrom(0).setSize(20) .execute().actionGet(); SearchHits hits1 = searchResponse1.getHits(); if (null == hits1 || hits1.totalHits() == 0) { log.error("使用matchPhrasePrefixQuery(\"name\", \"wa\")沒有查詢到任何結果!"); return; } else { for (SearchHit hit : hits1) { String json = hit.getSourceAsString(); Person newPerson = mapper.readValue(json, Person.class); System.out.println("name\t\t" + newPerson.getName()); System.out.println("sex\t\t" + newPerson.getSex()); System.out.println("age\t\t" + newPerson.getAge()); System.out.println("isStudent\t\t" + newPerson.getIsStudent()); } } } catch (Exception e) { e.printStackTrace(); } finally { if (null != client) { client.close(); } if (null != node) { node.close(); } } } }