ElasticSearch集成Spring之ElasticsearchTemplate

前面几篇我们学习了那么多ES知识，那么怎样运用到实际项目中去呢？本篇讲一讲ES与spring的集成，让ES能投入实际生产中去。

1、Maven依赖

<!-- elasticsearch的spring-data包 -->
<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-elasticsearch</artifactId>
    <version>x.y.z.RELEASE</version>
</dependency>

<!-- elasticsearch客户端，version填入本地安装好的ES版本号 -->
<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>transport</artifactId>
    <version>x.y.z</version>
</dependency>

 

spring-data-elasticsearch与elasticsearch的版本对应关系：

spring data elasticsearch	elasticsearch
3.2.x	6.5.0
3.1.x	6.2.2
3.0.x	5.5.0
2.1.x	2.4.0
2.0.x	2.2.0
1.3.x	1.5.2

maven仓库中的spring-data-elasticsearch版本：https://mvnrepository.com/artifact/org.springframework.data/spring-data-elasticsearch
注意：截止到 2018-12-17，一直还没有出3.2.x，如果你使用的elasticsearch是6.5.0以上的版本，建议elasticsearch降低到6.2.2，否则会出现很多未知的错误，这是个坑！

2、添加xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:elasticsearch="http://www.springframework.org/schema/data/elasticsearch"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/data/elasticsearch
http://www.springframework.org/schema/data/elasticsearch/spring-elasticsearch-1.0.xsd">
    <!-- 扫描包路径 -->
    <elasticsearch:repositories base-package="com.demo.elasticsearch.*" />

    <!-- 声明elasticsearch客户端 -->
    <elasticsearch:transport-client id="client" cluster-nodes="localhost:9300" cluster-name="home" />

    <!-- 声明elasticsearchTemplate -->
    <bean name="elasticsearchTemplate"
        class="org.springframework.data.elasticsearch.core.ElasticsearchTemplate">
        <constructor-arg name="client" ref="client" />
    </bean>
</beans>

 

3、使用elasticsearchTemplate

创建BookEntity实体：

public class BookEntity {
    private String author;
    private String name;
    private String id;
}

 

引用elasticsearchTemplate

@Autowired
private ElasticsearchTemplate elasticsearchTemplate;

 

创建索引

// 1、直接用名称创建
elasticsearchTemplate.createIndex("book");

// 2、填入class对象
elasticsearchTemplate.createIndex(BookEntity.class);

 

创建数据

单条数据：

BookEntity bookEntity = new BookEntity();
bookEntity.setId("2");
bookEntity.setAuthor("老李");
bookEntity.setName("一起学习es");

IndexQuery indexQuery = new IndexQueryBuilder()
                .withId(bookEntity.getId())
                .withObject(bookEntity)
                .build();
elasticsearchTemplate.index(indexQuery);

 

多条数据：

BookEntity bookEntity = new BookEntity();
bookEntity.setId("2");
bookEntity.setAuthor("老李");
bookEntity.setName("一起学习netty");

IndexQuery indexQuery1 = new IndexQueryBuilder()
        .withId(bookEntity.getId())
        .withObject(bookEntity)
        .build();
//        elasticsearchTemplate.index(indexQuery);
indexQueries.add(indexQuery1);

BookEntity bookEntity2 = new BookEntity();
bookEntity.setId("3");
bookEntity.setAuthor("老刘");
bookEntity.setName("netty菜鸟入门");

IndexQuery indexQuery2 = new IndexQueryBuilder()
        .withId(bookEntity2.getId())
        .withObject(bookEntity)
        .build();
indexQueries.add(indexQuery2);

elasticsearchTemplate.bulkIndex(indexQueries);

 

单字符串查询

SearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(QueryBuilders.queryStringQuery("菜鸟"))
        .withPageable(new PageRequest(0, 20))
        .build();
List<BookEntity> list = elasticsearchTemplate.queryForList(searchQuery, BookEntity.class);

 

排序

Pageable pageable= new PageRequest(0, 20,new Sort(Sort.Direction.DESC, "name"));
SearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(QueryBuilders.queryStringQuery("菜鸟"))
        .withPageable(pageable)
        .build();
Page<BookEntity> list = elasticsearchTemplate.queryForPage(searchQuery, BookEntity.class);

 

注意：如果出现此异常

java.lang.IllegalArgumentException: Fielddata is disabled on text fields by default

官方解释5.x后对排序，聚合这些操作用单独的数据结构(fielddata)缓存到内存里了，需要单独开启（主要是占用资源太多，所以是否开启，需要仔细斟酌）
关于fielddata更多内容：https://www.elastic.co/guide/en/elasticsearch/reference/current/fielddata.html

模糊查询

此模糊查询与mysql中的模糊查询不太一样，此模糊查询类似分词匹配。
比如有两条数据：1、我今天非常高兴 2、他摔倒很高兴
输入：今天高兴
这两条数据都能匹配上。

Pageable pageable = new PageRequest(0, 10);
SearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(QueryBuilders.matchQuery("name", "菜鸟"))
        .withPageable(pageable)
        .build();
List<BookEntity> list = elasticsearchTemplate.queryForList(searchQuery, BookEntity.class);

 

其余匹配

其余匹配类似mysql中like "%word%"的模糊匹配

Pageable pageable = new PageRequest(0, 10);
SearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(QueryBuilders.matchPhraseQuery("name", "菜鸟"))
        .withPageable(pageable)
        .build();
List<BookEntity> list = elasticsearchTemplate.queryForList(searchQuery, BookEntity.class);

 

Term全等查询

Pageable pageable = new PageRequest(0, 10);
SearchQuery searchQuery = new NativeSearchQueryBuilder()
        .withQuery(QueryBuilders.termQuery("name", "菜鸟"))
        .withPageable(pageable)
        .build();
List<BookEntity> list = elasticsearchTemplate.queryForList(searchQuery, BookEntity.class);

 

组合查询

即boolQuery，可以设置多个条件的查询方式。它的作用是用来组合多个Query，有四种方式来组合，must，mustnot，filter，should。
must代表返回的文档必须满足must子句的条件，会参与计算分值；
filter代表返回的文档必须满足filter子句的条件，但不会参与计算分值；
should代表返回的文档可能满足should子句的条件，也可能不满足，有多个should时满足任何一个就可以，通过minimum_should_match设置至少满足几个。
mustnot代表必须不满足子句的条件。

QueryBuilder filterQuery = QueryBuilders
                .boolQuery()
                .filter(QueryBuilders.termQuery("name", "菜鸟"))
                .filter(QueryBuilders.termQuery("author", "小菜"));
List<BookEntity> list = elasticsearchTemplate.queryForList(filterQuery, BookEntity.class);

 

结束

更多关于QueryBuilders的用法，可以看看elasticsearch的QueryBuilders类，或者查看文档：http://xbib.org/elasticsearch/2.1.1/apidocs/org/elasticsearch/index/query/QueryBuilders.html

更多关于ElasticsearchTemplate的用法，可以查看源码，或者查看文档：https://docs.spring.io/spring-data/elasticsearch/docs/current/api/org/springframework/data/elasticsearch/core/ElasticsearchTemplate.html