SpringBoot集成Elasticsearch

一.ES简介

elasticsearch是一个高度可扩展的开源全文搜索和分析引擎，可以快速的、近实时地对大数据进行存储、搜索和分析，用来支撑复杂的数据搜索需求和企业级应用，主要用于海量系统日志的数据查询与分析。

二.ES安装

1. 下载地址：https://www.elastic.co/downloads/elasticsearch。
2. 下载ES压缩包解压后，进入bin目录，双击elasticsearch.bat即可启动es
3. 启动es服务后，访问localhost:9200,浏览器出现如下信息说明启动成功.

{
  "name" : "YNFljfo",
  "cluster_name" : "my-application",
  "cluster_uuid" : "iuLpWK05SJGSqp5evk7Gpg",
  "version" : {
    "number" : "6.2.4",
    "build_hash" : "ccec39f",
    "build_date" : "2018-04-12T20:37:28.497551Z",
    "build_snapshot" : false,
    "lucene_version" : "7.2.1",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

三.head插件的安装

head插件可以很方便的操作es，head插件与es的关系就像navicat与MySQL数据库的关系，不过head插件的界面是通过访问网址浏览的。

1. 下载head插件：https://github.com/search?q=elasticsearch-head
2. 因为head插件依赖node环境，所以需要安装node.js:https://nodejs.org/en/download/
3. 运行head需要借助grunt命令，所以要安装。
   在cmd窗口进入node.js安装的根目录，然后执行npm install -g grunt -cli。
4. 安装pathomjs:
   在cmd命令窗口进入head插件解压后的根目录，然后执行npm install
5. 连接es: 设置跨域访问，在es的安装根目录的config目录下有elasticsearch.yml，在此文件中添加如下内容：

http.cors.enabled: true
http.cors.allow-origin: "*"

将cluster.name: my-application的注释取消

1. 运行head：
   在cmd命令窗口进入head插件解压后的根目录，然后执行grunt server，如下图就启动成功。

.png&originHeight=114&originWidth=472&size=5531&status=done&width=472)

1. 然后访问localhost:9100看到如下画面就安装成功

.png&originHeight=349&originWidth=990&size=28420&status=done&width=990)

四.Springboot集成ES

1. 添加依赖及配置application.properties文件

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
 </dependency>

spring.data.elasticsearch.cluster-name=my-application
spring.data.elasticsearch.cluster-nodes=127.0.0.1:9300

1. 创建实体类及响应体

@Data
@Document(indexName = "person")
@AllArgsConstructor
@NoArgsConstructor
public class Person implements Serializable {
    @Id
    private String skuId;
    private String name;
    private String address;
    private Integer age;
    private String sex;
    private String city;
}

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Response {

    private Integer code;
    private String message;
    private Object data;


    public static Response successMsg(){
        Response response=new Response();
        response.setCode(200);
        response.setMessage("请求成功");
        return response;
    }

    public static Response failed404(){
        Response response=new Response();
        response.setCode(404);
        response.setMessage("请求失败");
        return response;
    }
}

1. 创建es的Service

   自定义接口实现ElasticsearchRepository，类似于与数据库交互的dao层，提供了对es的基本操作。

public interface  PersonRepository extends ElasticsearchRepository<Person,String> {


}

@NoRepositoryBean
public interface ElasticsearchRepository<T, ID extends Serializable> extends ElasticsearchCrudRepository<T, ID> {
    <S extends T> S index(S var1);

    Iterable<T> search(QueryBuilder var1);

    Page<T> search(QueryBuilder var1, Pageable var2);

    Page<T> search(SearchQuery var1);

    Page<T> searchSimilar(T var1, String[] var2, Pageable var3);

    void refresh();

    Class<T> getEntityClass();
}

public interface PersonService {

    long count();

    Person save(Person person);

    void delete(Person person);

    Iterable<Person> getAll();

    List<Person> getByName(String name);

    Page<Person> pageQuery(Integer pageNo, Integer pageSize, String kw);
}

@Service
public class PersonServiceImpl implements PersonService {

    @Autowired
    private PersonRepository personRepository;

    @Override
    public long count() {
        return personRepository.count();
    }

    @Override
    public Person save(Person person) {
        return personRepository.save(person);
    }

    @Override
    public void delete(Person person) {
        personRepository.delete(person);
    }

    @Override
    public Iterable<Person> getAll() {
        return personRepository.findAll();
    }

    @Override
    public List<Person> getByName(String name) {
        List<Person> personList=new ArrayList<>();
        MatchQueryBuilder queryBuilder=new MatchQueryBuilder("name",name);
        Iterable<Person> personIterable=personRepository.search(queryBuilder);
        personIterable.forEach(personList::add);
        return personList;
    }

    @Override
    public Page<Person> pageQuery(Integer pageNo, Integer pageSize, String kw) {
        SearchQuery searchQuery=new NativeSearchQueryBuilder().withQuery(QueryBuilders.matchPhraseQuery("name",kw)).withPageable(PageRequest.of(pageNo,pageSize)).build();
        return personRepository.search(searchQuery);
    }
}

1. Junit测试

Springboot提供了ElasticsearchTemplate,也可实现的ES的数据操作。

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringEsApplicationTests {


    @Autowired
    public PersonService personService;

    @Autowired
    ElasticsearchTemplate elasticsearchTemplate;
    @Test
    public void contextLoads() {
        Person person=new Person("123456","zlc","西湖区",18,"男","hangzhou");
        personService.save(person);
        Person person1=new Person("98712","张三","余杭区",18,"男","hangzhou");
        IndexQuery indexQuery=new IndexQueryBuilder().withObject(person1).build();
        elasticsearchTemplate.index(indexQuery);

    }

}

1. 创建controller

@RestController
@RequestMapping("/es")
public class EsController {


    @Autowired
    PersonService personService;


    /**
     * 向es添加数据
     */
    @RequestMapping("/insert")
    public Object insert(@RequestBody Person person){
        JSONObject object=null;
        try {
          Person savePerson=  personService.save(person);
          object= (JSONObject) JSON.toJSON(savePerson);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return object;
    }


    /**
     * 从es删除数据
     * @param person
     * @return
     */
    @RequestMapping("/delete")
    public Object delete(@RequestBody Person person){

        try {
            personService.delete(person);
        } catch (Exception e) {
            e.printStackTrace();
            return Response.failed404();
        }
        return Response.successMsg();

    }


    /**
     * 查询操作
     * @param pageNo
     * @param pageSize
     * @param key
     * @return
     */
    @RequestMapping("/query")
    public Object query(@RequestParam(value = "pageNo",required = false)Integer pageNo,@RequestParam(value = "pageSize",required = false)Integer pageSize,
    @RequestParam(value = "key",required = false)String key){

        Response response=new Response();
        try {
            Page<Person> personPage= personService.pageQuery(pageNo,pageSize,key);
            response.setData(personPage);
        } catch (Exception e) {
            e.printStackTrace();
            return Response.failed404();
        }
        return response;

    }
}

通过Postman测试查询结果如下：
.png&originHeight=858&originWidth=1098&size=38028&status=done&width=1098)

五.错误解决

1. SpringBoot加载elasticsearch节点失败

failed to load elasticsearch nodes : org.elasticsearch.client.transport.NoNodeAvailableException: None of the configured nodes are available:

初步判定，应该是spring-boot-starter-data-elasticsearch与Elasticsearch 7.x版本不兼容造成的。
通过测试发现，将Elasticsearch降级到6.x版本，即可解决。
2.修改elasticsearch.yml后双击elasticsearch.bat闪退
原因是elasticsearch.yml默认是utf-8编码，所以添加的属性保存时也得是utf-8编码的。

六.源码下载地址

https://github.com/liankaizha...

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参考文献：

1.https://cloud.tencent.com/developer/article/1461537