分布式搜索Elasticsearch——QueryBuilders.matchPhrasePrefixQuery

   注：该文项目基础为分布式搜索Elasticsearch——项目过程（一）和分布式搜索Elasticsearch——项目过程（二），项目骨架可至这里下载。

        ES源代码中对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);
}

       如果你调用matchPhrasePrefixQuery时，text为中文，那么，很大可能是一种状况：你会发现，matchPhraseQuery和matchPhrasePrefixQuery没有任何差别。而当text为英文时，差别就显现出来了：matchPhraseQuery的text是一个英文单词，而matchPhrasePrefixQuery的text则无这一约束，你可以从一个英文单词中抽几个连接在一起的字母进行查询。

        示例代码如下所示：

/**
 * @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;

/**
 * 以短语形式查询，查询时关键字不会被分词，而是直接以一个字符串的形式查询
 *
 * @author Geloin
 *
 */
public class MatchPhrasePrefixQueryTest extends BaseTest {

    @Test
    public void matchPhrasePrefixQuery() {
        try {

            // 创建索引
            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("创建索引出错！");
            }

            // 检索
            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", "<span style="font-size:14px;">wa</span>")没有查询到任何结果！");
            } else {
                for (SearchHit hit : hits) {
                    String json = hit.getSourceAsString();

                    Person newPerson = mapper.readValue(json, Person.class);
                    System.out.println("name		" + newPerson.getName());
                    System.out.println("sex		" + newPerson.getSex());
                    System.out.println("age		" + newPerson.getAge());
                    System.out.println("isStudent		"
                            + newPerson.getIsStudent());
                }
            }

            System.out.println("===================================================");

            // 检索
            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")没有查询到任何结果！");
                return;
            } else {
                for (SearchHit hit : hits1) {
                    String json = hit.getSourceAsString();

                    Person newPerson = mapper.readValue(json, Person.class);
                    System.out.println("name		" + newPerson.getName());
                    System.out.println("sex		" + newPerson.getSex());
                    System.out.println("age		" + newPerson.getAge());
                    System.out.println("isStudent		"
                            + newPerson.getIsStudent());
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (null != client) {
                client.close();
            }
            if (null != node) {
                node.close();
            }
        }
    }
}

        你会发现，使用matchPhraseQuery并未查询出结果，而matchPhrasePrefixQuery查询出的，则是我们需要的结果。

http://blog.csdn.net/geloin/article/details/8939387