Elasticsearch

Elasticsearch (ES)是一個基于Lucene構建的開源、分布式、RESTful 介面全文搜索引擎，Elasticsearch 還是一個分布式檔案資料庫，其中每個欄位均是被索引的資料且可被搜索，它能夠擴展至數以百計的服務器存盤以及處理PB級的資料，它可以在很短的時間內在存盤、搜索和分析大量的資料，它通常作為具有復雜搜索場景情況下的核心發動機，es是由java語言撰寫的，

Elasticsearch就是為高可用和可擴展而生的，可以通過購置性能更強的服務器來完成，

官網

Elasticsearch：官方分布式搜索和分析引擎 | Elastichttps://www.elastic.co/cn/elasticsearch/

Spring Data

Spring Data是Spring 的一個子專案，用于簡化資料庫訪問，支持NoSQL和關系資料庫存盤，其主要目標是使資料庫的訪問變得方便快捷，

官網

Spring DataLevel up your Java code and explore what Spring can do for you.https://spring.io/projects/spring-data

Spring Data ElasticSearch

Spring Data ElasticSearch 基于 spring data API 簡化 elasticSearch操作，將原始操作elasticSearch的客戶端API進行封裝，Spring Data為Elasticsearch專案提供集成搜索引擎，Spring Data Elasticsearch POJO的關鍵功能區域為中心的模型與Elastichsearch互動檔案和輕松地撰寫一個存盤庫資料訪問層，

官網

Spring Data Elasticsearchhttps://spring.io/projects/spring-data-elasticsearch

代碼

創建maven專案，并引入依賴

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.6.RELEASE</version>
        <relativePath/>
    </parent>

 <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
    </dependencies>

在resources檔案夾下創建application.properties檔案

application.properties內容如下

# es 服務地址
elasticsearch.host=部署es服務器的ip
# es 服務埠
elasticsearch.port=9200
# 配置日志級別,開啟 debug 日志
logging.level.com.es=debug

創建MainApplication

package com.es;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class MainApplication {
    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class, args);
    }
}

創建ElasticSearch組態檔ElasticsearchConfig

package com.es.config;

import lombok.Data;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestClientBuilder;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.config.AbstractElasticsearchConfiguration;

@ConfigurationProperties(prefix = "elasticsearch")
@Configuration
@Data
public class ElasticsearchConfig  extends AbstractElasticsearchConfiguration {

    private String host ;
    private Integer port ;

    @Override
    public RestHighLevelClient elasticsearchClient() {
        RestClientBuilder builder = RestClient.builder(new HttpHost(host, port));
        RestHighLevelClient restHighLevelClient = new
                RestHighLevelClient(builder);
        return restHighLevelClient;
    }
}

創建物體類Person

package com.es.DO;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;

@Data
@Document(indexName = "contact", shards = 3, replicas = 1)
public class Person {

    /**
     * 主鍵 id
     */
    @Id
    public Long id;

    /**
     * 姓名 name
     */
    @Field(type = FieldType.Text, analyzer = "ik_max_word")
    public String name;

    /**
     * 年齡 age
     */
    @Field(type = FieldType.Integer)
    public int age;

    /**
     * 地址 address
     */
    @Field(type = FieldType.Keyword, index = false)
    public String address;
}

配置Person的Dao類，PersonDao

package com.es.dao;

import com.es.DO.Person;
import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface PersonDao extends ElasticsearchRepository<Person, Long>{

}

創建測驗類SpringDataESIndexTest，測驗類跟啟動類在同一個包下，不然啟動會報錯，

package com.es.test;

import com.es.DO.Person;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
import org.springframework.test.context.junit4.SpringRunner;

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

    //注入 ElasticsearchRestTemplate
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;

    //創建索引并增加映射配置
    @Test
    public void createIndex(){
        //創建索引，系統初始化會自動創建索引
        System.out.println("創建索引");
    }

    @Test
    public void deleteIndex(){
        //創建索引，系統初始化會自動創建索引
        boolean flg = elasticsearchRestTemplate.deleteIndex(Person.class);
        System.out.println("洗掉索引 = " + flg);
    }
}

測驗

對索引創建及洗掉進行測驗

http://IP地址:9200/_cat/indices?v，用瀏覽器或Postman等工具訪問該地址來看結果

運行createIndex測驗方法

運行deleteIndex測驗方法

檔案操作

新加SpringDataESPersonDaoTest測驗類

新增

    @Autowired
    private PersonDao personDao;
    /**
     * 新增
     */
    @Test
    public void save(){
        Person person = new Person();
        person.setId(1L);
        person.setName("張三");
        person.setAge(21);
        person.setAddress("北京市海淀區");
        personDao.save(person);
    }

測驗地址：http://IP地址:9200/contact/_doc/1

修改

    @Autowired
    private PersonDao personDao;

    //修改
    @Test
    public void update(){
        Person person = new Person();
        person.setId(1L);
        person.setName("張三");
        person.setAge(21);
        person.setAddress("北京市朝陽區");
        personDao.save(person);
    }

測驗地址：http://IP地址:9200/contact/_doc/1

根據 id 查詢

    @Autowired
    private PersonDao personDao;    
    
    //根據 id 查詢
    @Test
    public void findById(){
        Person person = personDao.findById(1L).get();
        System.out.println(person);
    }

列印成功

列印所有

    @Autowired
    private PersonDao personDao;

    @Test
    public void findAll(){
        Iterable<Person> persons = personDao.findAll();
        for (Person person : persons) {
            System.out.println(person);
        }
    }

洗掉

    @Autowired
    private PersonDao personDao;
    
    @Test
    public void delete(){
        Person person = new Person();
        person.setId(1L);
        personDao.delete(person);
    }

測驗地址：http://IP地址:9200/contact/_doc/1

已洗掉

批量新增

    @Autowired
    private PersonDao personDao;

    //批量新增
    @Test
    public void saveAll(){
        List<Person> personList = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Person person = new Person();
            person.setId(Long.valueOf(i));
            person.setName("["+i+"]張三");
            person.setAge(21+i);
            person.setAddress("北京市海淀區");
            personList.add(person);
        }
        personDao.saveAll(personList);
    }

測驗地址：http://ip地址:9200/contact/_search

分頁查詢

    @Autowired
    private PersonDao personDao;
    
    @Test
    public void findByPageable(){
        //設定排序(排序方式，正序還是倒序，排序的 id)
        Sort sort = Sort.by(Sort.Direction.DESC,"id");
        int currentPage=0;//當前頁，第一頁從 0 開始， 1 表示第二頁
        int pageSize = 5;//每頁顯示多少條
        //設定查詢分頁
        PageRequest pageRequest = PageRequest.of(currentPage, pageSize,sort);
        //分頁查詢
        Page<Person> personPage = personDao.findAll(pageRequest);
        for (Person person : personPage.getContent()) {
            System.out.println(person);
        }
    }

查詢成功，查出第一頁

完整代碼如下

package com.es.test;

import com.es.DO.Person;
import com.es.dao.PersonDao;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.ArrayList;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringDataESPersonDaoTest {
    @Autowired
    private PersonDao personDao;
    /**
     * 新增
     */
    @Test
    public void save(){
        Person person = new Person();
        person.setId(1L);
        person.setName("張三");
        person.setAge(21);
        person.setAddress("北京市海淀區");
        personDao.save(person);
    }
    //POSTMAN, GET http://IP地址:9200/contact/_doc/1

    //修改
    @Test
    public void update(){
        Person person = new Person();
        person.setId(1L);
        person.setName("張三");
        person.setAge(21);
        person.setAddress("北京市朝陽區");
        personDao.save(person);
    }
    //POSTMAN, GET http://IP地址:9200/contact/_doc/1


    //根據 id 查詢
    @Test
    public void findById(){
        Person person = personDao.findById(1L).get();
        System.out.println(person);
    }

    @Test
    public void findAll(){
        Iterable<Person> persons = personDao.findAll();
        for (Person person : persons) {
            System.out.println(person);
        }
    }

    //洗掉
    @Test
    public void delete(){
        Person person = new Person();
        person.setId(1L);
        personDao.delete(person);
    }
    //POSTMAN, GET http://IP地址:9200/contact/_doc/1

    //批量新增
    @Test
    public void saveAll(){
        List<Person> personList = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            Person person = new Person();
            person.setId(Long.valueOf(i));
            person.setName("["+i+"]張三");
            person.setAge(21+i);
            person.setAddress("北京市海淀區");
            personList.add(person);
        }
        personDao.saveAll(personList);
    }

    //分頁查詢
    @Test
    public void findByPageable(){
        //設定排序(排序方式，正序還是倒序，排序的 id)
        Sort sort = Sort.by(Sort.Direction.DESC,"id");
        int currentPage=0;//當前頁，第一頁從 0 開始， 1 表示第二頁
        int pageSize = 5;//每頁顯示多少條
        //設定查詢分頁
        PageRequest pageRequest = PageRequest.of(currentPage, pageSize,sort);
        //分頁查詢
        Page<Person> personPage = personDao.findAll(pageRequest);
        for (Person person : personPage.getContent()) {
            System.out.println(person);
        }
    }
}

檔案搜索

新建測驗類SpringDataESSearchTest

termQuery

    @Autowired
    private PersonDao personDao;
    /**
     * term 查詢
     * search(termQueryBuilder) 呼叫搜索方法，引數查詢構建器物件
     */
    @Test
    public void termQuery(){
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("name", "[8]張三");
        Iterable<Person> persons = personDao.search(termQueryBuilder);
        for (Person person : persons) {
            System.out.println(person);
        }
    }

termQuery加分頁

    @Autowired
    private PersonDao personDao;    
    /**
     * term 查詢加分頁
     */
    @Test
    public void termQueryByPage(){
        int currentPage= 0 ;
        int pageSize = 5;
        //設定查詢分頁
        PageRequest pageRequest = PageRequest.of(currentPage, pageSize);
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("name", "[8]張三");
        Iterable<Person> persons =
                personDao.search(termQueryBuilder,pageRequest);
        for (Person person : persons) {
            System.out.println(person);
        }
    }

只有一條name為[8]張三的記錄

完整代碼如下

package com.es.test;

import com.es.DO.Person;
import com.es.dao.PersonDao;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.TermQueryBuilder;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.PageRequest;
import org.springframework.test.context.junit4.SpringRunner;

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

    @Autowired
    private PersonDao personDao;
    /**
     * term 查詢
     * search(termQueryBuilder) 呼叫搜索方法，引數查詢構建器物件
     */
    @Test
    public void termQuery(){
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("name", "[8]張三");
        Iterable<Person> persons = personDao.search(termQueryBuilder);
        for (Person person : persons) {
            System.out.println(person);
        }
    }
    /**
     * term 查詢加分頁
     */
    @Test
    public void termQueryByPage(){
        int currentPage= 0 ;
        int pageSize = 5;
        //設定查詢分頁
        PageRequest pageRequest = PageRequest.of(currentPage, pageSize);
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("name", "[8]張三");
        Iterable<Person> persons =
                personDao.search(termQueryBuilder,pageRequest);
        for (Person person : persons) {
            System.out.println(person);
        }
    }

}