ElasticSearch& ElasticSearch JAVA API
ElasticSearch
几个概念
1.Elastic Search特点：分布式 、REstFul风格、数据分析引擎
2.Elastic stack :包括Es、Kibana、Logstash、Beats (亦称为ELK Static)
特点：任意数据来源和格式、实时分析、搜索、可视化
3.类比
相对于solr特点：易于安装、轻巧、json配置 、监控和指标
安装和启动
https://www.elastic.co/cn/downloads/elasticsearch
Windows版本后解压缩后启动bin/elasticsearch.bat
访问localhost:9200 如下信息：
Es基础操作
一、索引操作
1.创建索引 put
创建一个名为shopping 的索引
Put http://127.0.0.1:9200/shopping Put具有幂等性
2.获取索引信息 get
3.查看所有索引信息 get
http://127.0.01:9200/_cat/indices?v
4.删除某个索引 delete
二、文档操作
1.创建文档post
POST http://127.0.0.1:9200/shopping/_doc 数据写在请求body中 json格式
自定义id http://127.0.0.1:9200/shopping/_doc/001，
2.查询文档get
●通过ID查询
Get http://127.0.0.1:9200/shopping/_doc/001
●获取所有数据
Get http://127.0.0.1:9200/shopping/_search
3.更新文档 put/post
●全局更新 更新整条json
Post/put http://127.0.0.1:9200/shopping/_doc/001
●局部修改 只更新json的相应键的值
Post http://127.0.0.1:9200/shopping/_update/001
4.删除文档 delete
Delete http://127.0.0.1:9200/shopping/_doc/001
三、查询
1.条件查询
条件查询1 http://127.0.0.1:9200/shopping/_search?q=category:小米
●条件查询2（推荐）
2.分页查询、选取想要的字段、排序
From size分页 _source选取字段 sort 排序
按照price(价格)倒序
3.多条件查询和范围查询
- Query中：
- Bool:条件
- Must:（与）
- Should:（或）
- Bool:条件
- filter 过滤
- range 范围
4.全文检索\完全匹配、高亮查询
match全文检索
match_phrase完全匹配
高亮查询
5.聚合查询
//term分组 avg平均值 max min sum ...
6.映射关系
为user索引创建映射关系
四、---
所有doc结构
{
"took": 541, #响应时间:ms
"timed_out": false, #超时：false
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": { #命中的集合
"total": { #数量
"value": 1,
"relation": "eq"
},
"max_score": 1.0, #集合中最大的权重
"hits": [ #命中的集合
{
"_index": "user", #索引
"_type": "_doc", #类型
"_id": "001", #id
"_score": 1.0, #权重
"_source": { #记录详情
"age": "23",
"gender": "女",
"name": "李啊"
}
}
]
}
}
单条doc结构
{
"_index": "user",
"_type": "_doc",
"_id": "001",
"_version": 1,
"_seq_no": 0,
"_primary_term": 1,
"found": true,
"_source": {
"age": "23",
"gender": "女",
"name": "李康平"
}
}
JAVA API
1.pom.xml
<!-- es-->
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>7.8.0</version>
</dependency>
<!--es客户端-->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.8.0</version>
</dependency>
<!--junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!--fastjson-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.53</version>
</dependency>
<!--log4j-->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.8.2</version>
</dependency>
2.实体类
public class User {
private String name;
private Integer age;
private String gender;
public User(String name, Integer age, String gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
}
3.索引的操作
/**
* 索引的操作 新增、删除、查询
*/
public class ES_Index {
public static void main(String[] args) throws IOException {
//ES客户端
RestHighLevelClient esClient = new RestHighLevelClient(
RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
);
//创建索引
// boolean flag=new ES_Index().createIndex(esClient,"user");
// System.out.println(flag);
//查询
// String s=new ES_Index().searchIndex(esClient,"user").toString();
// System.out.println(s);
//删除索引
// boolean b=new ES_Index().deleteIndex(esClient,"user");
// System.out.println(b);
//关闭ES客户端
esClient.close();
}
/**
* 创建索引
* @param client RestHighLevelClient ES客户端
* @param indexName 索引名称
* @return boolean 是否创建成功
*/
public boolean createIndex(RestHighLevelClient client,String indexName) throws IOException {
CreateIndexRequest userIndex = new CreateIndexRequest(indexName);
CreateIndexResponse response= client.indices().create(userIndex, RequestOptions.DEFAULT);
boolean acknowledged = response.isAcknowledged();
return acknowledged;
}
/**
*删除索引
* @param client RestHighLevelClient ES客户端
* @param indexName 索引名称
* @return boolean 是否删除成功
* @throws IOException
*/
public boolean deleteIndex(RestHighLevelClient client,String indexName) throws IOException {
DeleteIndexRequest request= new DeleteIndexRequest(indexName);
AcknowledgedResponse delete = client.indices().delete(request, RequestOptions.DEFAULT);
return delete.isAcknowledged();
}
public Map searchIndex(RestHighLevelClient client,String indexName) throws IOException {
GetIndexRequest request=new GetIndexRequest(indexName);
GetIndexResponse getIndexResponse = client.indices().get(request, RequestOptions.DEFAULT);
//这边对应的是 get Index返回的参数
Map<String,Map> resMap=new HashMap();
resMap.put("aliases",getIndexResponse.getAliases());
resMap.put("mappings",getIndexResponse.getMappings());
resMap.put("settings",getIndexResponse.getSettings());
return resMap;
}
}
4.文档的操作
/**
* 文档的操作
*
* 插入、更新 IndexRequest request.source() IndexResponse =client.index()
* 局部更新 UpdateRequest request.doc() UpdateResponse=client.update()
* 删除 DeleteReqeust
* 查询 GetRequest
*
* 批量操作 BulkRequest.add(...Request);
*
*/
public class ES_Doc {
/**
* 插入/更新 User
* @param client
* @param indexName
* @param user 实例类
* @param id
* @return
* @throws IOException
*/
public Map createDoc(RestHighLevelClient client, String indexName, User user, String id) throws IOException {
IndexRequest request = new IndexRequest();
//request index&id
request.index(indexName).id(id);
//request source
String userJson = JSON.toJSONString(user);
request.source(userJson, XContentType.JSON);
//发送并响应
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
Map<String, String> resMap = new HashMap();
resMap.put("id", response.getId());
resMap.put("result", response.getResult().toString());
resMap.put("index", response.getIndex());
return resMap;
}
/**
* 局部修改文档-修改年龄
* @param
* @throws IOException
*/
public Map updateDoc(RestHighLevelClient client,String indexName,String id,String age) throws IOException {
UpdateRequest request=new UpdateRequest();
//指定indexi&d
request.index(indexName).id(id);
//指定内容
request.doc(XContentType.JSON,"age",age);
//发送并响应
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
Map<String, String> resMap = new HashMap();
resMap.put("id", response.getId());
resMap.put("result", response.getResult().toString());
resMap.put("index", response.getIndex());
return resMap;
}
/**
* 查询文档 返回json
* @param client
*/
public String searchDoc(RestHighLevelClient client,String indexName,String id) throws IOException {
GetRequest request=new GetRequest();
request.index(indexName).id(id);
GetResponse response = client.get(request, RequestOptions.DEFAULT);
return response.getSourceAsString();
}
/**
* 根据id删除文档
* @param client
* @param indexName
* @param id
*/
public String deleteDoc(RestHighLevelClient client,String indexName,String id) throws IOException {
DeleteRequest request=new DeleteRequest();
request.index(indexName).id(id);
DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
return response.getResult().toString();
}
public void executebatch(RestHighLevelClient client,String indexName) throws IOException {
BulkRequest bulkRrequest=new BulkRequest();
//这里可以将多个 IndexRequest\UpdateRequest\DeleteRequest 放入
for(int i=0;i<=7;i++){
IndexRequest indexRequest=new IndexRequest();
indexRequest.index(indexName).id("00"+i);
User user=new User("张"+i,18+i,"男");
String userJson=JSON.toJSONString(user);
indexRequest.source(userJson, XContentType.JSON);
bulkRrequest.add(indexRequest);
}
BulkResponse bulkResponse = client.bulk(bulkRrequest, RequestOptions.DEFAULT);
}
public static void main(String[] args) throws IOException {
//ES客户端
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
);
//insert
// User user = new User("何必", 33, "男");
// Map<String,String> map=new ES_Doc().createDoc(client, "user", user, "003");
// System.out.println(map);
//update
// Map<String,String> map=new ES_Doc().updateDoc(client,"user","001","31");
// System.out.println(map);
//search By id
// String s=new ES_Doc().searchDoc(client,"user","002");
// System.out.println(s);
//delete By id
// String dd=new ES_Doc().deleteDoc(client,"user","003");
// System.out.println(dd);
new ES_Doc().executebatch(client,"user");
//关闭ES客户端
client.close();
}
}
5.查询
/**
* 查询:
* 全量、条件、组合、范围、模糊
* 对查询结果：
* 分页、排序、选取字段、高亮、聚合、分组
*/
public class ES_Search {
public static void main(String[] args) throws IOException {
//ES客户端
RestHighLevelClient esClient = new RestHighLevelClient(
RestClient.builder(new HttpHost("127.0.0.1", 9200, "http"))
);
//查询
SearchRequest searchRequest=new SearchRequest();
searchRequest.indices("user");
//1.全量查询 matchAllQuery
// QueryBuilder query= QueryBuilders.matchAllQuery();
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// searchRequest.source(search);
//2.条件查询 termQuery
// QueryBuilder query=QueryBuilders.termQuery("age",23);
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// searchRequest.source(search);
//3.组合查询 boolQuery
// BoolQueryBuilder query = QueryBuilders.boolQuery();
// query.must(QueryBuilders.matchQuery("age",23));
// query.should(QueryBuilders.matchQuery("gender","男"));
// query.mustNot(QueryBuilders.matchQuery("gender","女"));
// SearchSourceBuilder search = new SearchSourceBuilder().query(query);
// searchRequest.source(search);
//4.范围查询 rangeQuery
// RangeQueryBuilder query = QueryBuilders.rangeQuery("age");
// query.gte(20);
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// searchRequest.source(search);
//5.模糊查询 fuzzyQuery
// FuzzyQueryBuilder query = QueryBuilders.fuzzyQuery("name", "张").fuzziness(Fuzziness.ONE);
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// searchRequest.source(search);
//a.分页
// QueryBuilder query = QueryBuilders.matchAllQuery();
// SearchSourceBuilder search = new SearchSourceBuilder().query(query);
// search.from(0);
// search.size(3);
// searchRequest.source(search);
//b.排序-只能对数值型排序
// QueryBuilder query = QueryBuilders.matchAllQuery();
// SearchSourceBuilder search = new SearchSourceBuilder().query(query);
// search.sort("age", SortOrder.DESC);
// searchRequest.source(search);
//c.过滤字段
// QueryBuilder query = QueryBuilders.matchAllQuery();
// SearchSourceBuilder search = new SearchSourceBuilder().query(query);
// search.fetchSource(new String[]{"name"},new String[]{});//String[] includes ,String[] excludes
// searchRequest.source(search);
//d。高亮查询
// TermQueryBuilder query = QueryBuilders.termQuery("name", "张");
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// HighlightBuilder highlighter = new HighlightBuilder();
// highlighter.preTags("<font color:'red'>");
// highlighter.postTags("</font>");
// highlighter.field("name");
// search.highlighter(highlighter);
// searchRequest.source(search);
//e.聚合查询
// MatchAllQueryBuilder query = QueryBuilders.matchAllQuery();
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// AggregationBuilder aggregationBuilder= AggregationBuilders.avg("avgAge").field("age");
// search.aggregation(aggregationBuilder);
// searchRequest.source(search);
//f.分组查询
// MatchAllQueryBuilder query = QueryBuilders.matchAllQuery();
// SearchSourceBuilder search=new SearchSourceBuilder().query(query);
// AggregationBuilder aggregationBuilder= AggregationBuilders.terms("ageGroup").field("age");
// search.aggregation(aggregationBuilder);
// searchRequest.source(search);
//结果
SearchResponse searchResponse = esClient.search(searchRequest, RequestOptions.DEFAULT);
Arrays.asList(searchResponse.getHits().getHits()).forEach(
a-> System.out.println(a)
);
//关闭ES客户端
esClient.close();
}
}
