敞开生长之旅!这是我参与「日新方案 12 月更文应战」的第30天,点击检查活动详
一、ElasticSearch 介绍
Elasticsearch 是一个分布式、高扩展、高实时的查找与数据剖析引擎。它能很方便的使很多数据具有查找、剖析和探索的能力。充分利用Elasticsearch的水平伸缩性,能使数据在出产环境变得更有价值。Elasticsearch 的完成原理主要分为以下几个过程,首先用户将数据提交到Elasticsearch 数据库中,再经过分词控制器去将对应的句子分词,将其权重和分词成果一并存入数据,当用户查找数据时候,再根据权重将成果排名,打分,再将回来成果出现给用户。
ElasticSearch 官网地址:www.elastic.co/cn/
二、环境预备
在开始开发之前,我们需求预备一些环境装备:
- jdk 1.8 或其他更高版别
- 开发工具 IDEA
- 管理依靠 Maven
- ElasticSearch环境,此处运用docker建立,ElasticSearch 版别为7.17.7
- Spring Boot 2.X
三、创立Spring Boot项目导入依靠
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</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-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
注意:依靠版别有必要与你当时所用的版别保持一致,否则衔接失利
四、创立高级客户端
新建config目录寄存项目装备类
@Configuration
public class ElasticSearchClientConfig {
@Bean
public RestHighLevelClient restHighLevelClient(){
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("服务器IP地址", 9200, "http")));
return client;
}
}
五、基本操作
索引操作
@SpringBootTest
class DemoApplicationTests {
@Autowired
private RestHighLevelClient restHighLevelClient;
/**
* 创立索引
**/
@Test
void testCreateIndex() throws IOException {
//1.创立索引恳求
CreateIndexRequest request = new CreateIndexRequest("lt");
//2.客户端履行恳求IndicesClient,履行create办法创立索引,恳求后取得呼应
CreateIndexResponse response=
restHighLevelClient.indices().create(request, RequestOptions.DEFAULT);
System.out.println(response);
}
/**
* 判断索引是否存在
**/
@Test
void testExistIndex() throws IOException {
//1.查询索引恳求
GetIndexRequest request=new GetIndexRequest("lt");
//2.履行exists办法判断是否存在
boolean exists=restHighLevelClient.indices().exists(request,RequestOptions.DEFAULT);
System.out.println(exists ? "存在" : "消失");
}
/**
* 删去索引
**/
@Test
void testDeleteIndex() throws IOException {
//1.删去索引恳求
DeleteIndexRequest request=new DeleteIndexRequest("lt");
//履行delete办法删去指定索引
AcknowledgedResponse delete = restHighLevelClient.indices().delete(request, RequestOptions.DEFAULT);
System.out.println(delete.isAcknowledged() ? "删去成功" : "删去失利");
}
}
文档操作
创立实体类User
@Data
@NoArgsConstructor
@AllArgsConstructor
@ToString
public class User {
private String name;
private Integer age;
private String[] funny;
}
文档相关操作代码
/**
* 创立文档
**/
@Test
void testAddUser() throws IOException {
//1.创立目标
User user=new User("小赵",21,new String[]{"篮球","吃饭"});
//2.创立恳求
IndexRequest request=new IndexRequest("lt");
//3.设置规矩 PUT /lt/_doc/1
//设置文档id=6,设置超时=1s等,不设置会运用默认的
//同时支撑链式编程如 request.id("6").timeout("1s");
request.id("6");
request.timeout("1s");
//4.将数据放入恳求,要将目标转化为json格式
//XContentType.JSON,告诉它传的数据是JSON类型
request.source(JSONValue.toJSONString(user), XContentType.JSON);
//5.客户端发送恳求,获取呼应成果
IndexResponse indexResponse=restHighLevelClient.index(request,RequestOptions.DEFAULT);
System.out.println(indexResponse.toString());
System.out.println(indexResponse.status());
}
/**
* 获取文档数据
**/
@Test
void testGetUser() throws IOException {
//1.创立恳求,指定索引、文档id
GetRequest request=new GetRequest("lt","1");
GetResponse getResponse=restHighLevelClient.get(request,RequestOptions.DEFAULT);
System.out.println(getResponse);//获取呼应成果
//getResponse.getSource() 回来的是Map集合
System.out.println(getResponse.getSourceAsString());//获取呼应成果source中内容,转化为字符串
}
/**
* 更新文档
**/
@Test
void testUpdateUser() throws IOException {
//1.创立恳求,指定索引、文档id
UpdateRequest request=new UpdateRequest("lt","6");
User user =new User("xiaozhao",21,new String[]{"xxx","xxx"});
//将创立的目标放入文档中
request.doc(JSONValue.toJSONString(user),XContentType.JSON);
UpdateResponse updateResponse=restHighLevelClient.update(request,RequestOptions.DEFAULT);
System.out.println(updateResponse.status());
}
/**
* 删去文档
**/
@Test
void testDeleteUser() throws IOException {
//创立删去恳求,指定要删去的索引与文档ID
DeleteRequest request=new DeleteRequest("lt","6");
DeleteResponse updateResponse=restHighLevelClient.delete(request,RequestOptions.DEFAULT);
System.out.println(updateResponse.status());
}
批量插入数据
/**
* 批量插入数据
**/
@Test
void testBulkAddUser() throws IOException {
BulkRequest bulkRequest=new BulkRequest();
//设置超时
bulkRequest.timeout("10s");
ArrayList<User> list=new ArrayList<>();
list.add(new User("Java",25,new String[]{"内卷"}));
list.add(new User("Go",18,new String[]{"内卷"}));
list.add(new User("C",30,new String[]{"内卷"}));
list.add(new User("C++",26,new String[]{"内卷"}));
list.add(new User("Python",20,new String[]{"内卷"}));
int id=1;
//批量处理恳求
for (User u :list){
//不设置id会生成随机id
bulkRequest.add(new IndexRequest("ljx666")
.id(""+(id++))
.source(JSONValue.toJSONString(u),XContentType.JSON));
}
BulkResponse bulkResponse=restHighLevelClient.bulk(bulkRequest,RequestOptions.DEFAULT);
System.out.println(bulkResponse.hasFailures());//是否履行失利,false为履行成功
}
其他操作
@Test
void testSearch() throws IOException {
SearchRequest searchRequest=new SearchRequest("ljx666");//里面能够放多个索引
SearchSourceBuilder sourceBuilder=new SearchSourceBuilder();//结构查找条件
//此处能够运用QueryBuilders工具类中的办法
//1.查询所有
sourceBuilder.query(QueryBuilders.matchAllQuery());
//2.查询name中含有Java的
sourceBuilder.query(QueryBuilders.multiMatchQuery("java","name"));
//3.分页查询
sourceBuilder.from(0).size(5);
//4.按照score正序摆放
//sourceBuilder.sort(SortBuilders.scoreSort().order(SortOrder.ASC));
//5.按照id倒序摆放(score会失效回来NaN)
//sourceBuilder.sort(SortBuilders.fieldSort("_id").order(SortOrder.DESC));
//6.给指定字段加上指定高亮样式
HighlightBuilder highlightBuilder=new HighlightBuilder();
highlightBuilder.field("name").preTags("<span>").postTags("</span>");
sourceBuilder.highlighter(highlightBuilder);
searchRequest.source(sourceBuilder);
SearchResponse searchResponse=restHighLevelClient.search(searchRequest,RequestOptions.DEFAULT);
//获取总条数
System.out.println(searchResponse.getHits().getTotalHits().value);
//输出成果数据(如果不设置回来条数,大于10条默认只回来10条)
SearchHit[] hits=searchResponse.getHits().getHits();
for(SearchHit hit :hits){
System.out.println("分数:"+hit.getScore());
Map<String,Object> source=hit.getSourceAsMap();
System.out.println("index->"+hit.getIndex());
System.out.println("id->"+hit.getId());
for(Map.Entry<String,Object> s:source.entrySet()){
System.out.println(s.getKey()+"--"+s.getValue());
}
}
}
六、总结
- 依靠版别有必要与你当时所用的版别保持一致,否则衔接失利。
- 如果添加时不指定文档ID,他就会随机生成一个ID,ID唯一。
- 创立文档时若该ID已存在,发送创立文档恳求后会更新文档中的数据。
- 更新文档时需求将实体目标中的属性全部指定值,否则会被设置为空,如果只设置了一个字段,那么只要该字段会被修正成功,其他会被修正为null。
-
hasFailures()
办法是回来是否失利,即它的值为false时说明上传成功 - elasticsearch很耗费内存,极力推荐运用docker部署运行