ElasticSearch

ES支持的数据类型

• text：全文搜索字符串
• keyword：用于精确字符串匹配和聚合
• date 及 date_nanos：格式化为日期或数字日期的字符串
• byte, short, integer, long：整数类型
• boolean：布尔类型
• float，double，half_float：浮点数类型
• 分级的类型：object 及 nested。

java.net.UnknownHostException

如果你在使用docker部署elasticsearch集群服务中出现如下错误：java.net.UnknownHostException，那么请调大分配给docker的内存空间至4个G，官网给出的解决方案就是提升docker可用内存至4GB

es客户端配置

https://docs.spring.io/spring-data/elasticsearch/docs/4.0.2.RELEASE/reference/html/#elasticsearch.clients.configuration

hightlevelclent

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/7.13/index.html

ik分词器

ES 中文分词器 ik分词器地址，分词器版本要和es版本一致
https://github.com/medcl/elasticsearch-analysis-ik/releases

REST 高级客户端

REST 高级客户端的 javadoc 可以在https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-high-level-client/7.13.4/index.html找到。

# - 创建索引库：PUT /索引库名
# - 查询索引库：GET /索引库名
# - 删除索引库：DELETE /索引库名
# - 添加字段：PUT /索引库名/_mapping
# 删除索引库
DELETE /mswk_csj_user
# 新建索引库
PUT /mswk_csj_user
# 查询索引库
GET /mswk_csj_user
# 测试分词器是否设置成功
GET /_analyze
{
  "analyzer": "ik_max_word",
  "text": "明思维科123"
}
# 创建索引库时指定mapping
PUT /mswk_csj_user
{
  "mappings": {
    "properties": {
      "name":{
        "type": "text"
      }
    }
  }
}
# mapping不支持修改,只能新增
PUT /mswk_csj_user/_mapping
{
  "properties":{
    "id":{
      "type":"keyword"
    }
  }
}
# 索引库新增映射关系
PUT /mswk_csj_user/_mapping
{
  "properties": {
    "name": {
      "type": "keyword"
    },
    "age": {
      "type": "integer"
    },
    "address": {
      "type": "text",
      "analyzer": "ik_max_word",
      "index": true
    }
  }
}

# 插入文档,未指定id自动生成,指定id如果存在-更新
POST /mswk_csj_user/_doc/1
{
  "name":"陈帅杰",
  "age":"25",
  "address":"北京市西城区",
  "id":"41412321312"
}
# 根据id查询文档
GET /mswk_csj_user/_doc/1
# 删除文档,指定id
DELETE /mswk_csj_user/_doc/1
# put 全量更改  post 局部修改
PUT /mswk_csj_user/_doc/1
{
  "name":"明思维科",
  "age":"18",
  "address":"嘿嘿额黑",
  "id":"23123123"
}
POST /mswk_csj_user/_update/1
{
  "doc": {
    "name":"北京市"
  }
}

java.lang.NoSuchMethodError: com.fasterxml.jackson.core.JsonParser.getReadCa
jackson版本过高，降低版本

docker run -d \
    --name es_7.13.0 \
    -e "ES_JAVA_OPTS=-Xms512m -Xmx512m" \
    -e "discovery.type=single-node" \
    -v es-data:/usr/share/elasticsearch/data \
    -v es-plugins:/usr/share/elasticsearch/plugins \
    -v es-logs:/usr/share/elasticsearch/logs \
    --privileged \
    --network es_net_7.13.0 \
    -p 9200:9200 \
    -p 9300:9300 \
elasticsearch:7.13.0
docker run -d \
  --name kibana_7.13.0 \
  -e ELASTICSEARCH_HOSTS=http://es_7.13.0:9200 \
  --network=es_net_7.13.0 \
  -p 5601:5601  \
kibana:7.13.0

ES SQL

es 7.13 sql语句

# 简单查询   
# _sql:sql查询方式
# format：返回数据格式  如 txt 类似数据库查询结果，也可以指定json格式
POST /_sql?format=txt
{
  "query": """
  SELECT * FROM "user"
  """
}
# 带条件查询，在kibana中建议sql使用三引号，条件字符串使用单引号
POST /_sql?format=txt
{
  "query": """
  SELECT name FROM "user" where name = '陈帅杰'
  """
}
# 使用DSL筛选条件
POST /_sql?format=txt
{
  "query": """
  SELECT * FROM "user"
  """,
  "filter":{
    "term": {
      "name.keyword": "陈帅杰"
    }
  }
}
# limit 分页   ORDER BY 排序
POST /_sql?format=txt
{
  "query": """
  SELECT * FROM "user" ORDER BY id desc limit 2
  """
}
# translate 支持将sql转换为es dsl查询
POST /_sql/translate
{
  "query": """
  SELECT * FROM "user" ORDER BY id desc
  """,
  "fetch_size": 2
}

<!--es jdbc-->
<dependency>
  <groupId>org.elasticsearch.plugin</groupId>
  <artifactId>x-pack-sql-jdbc</artifactId>
  <version>${elasticsearch.version}</version>
</dependency>

  # es数据源
  esDatasource:
    url: jdbc:es://http://172.16.88.128:9200
    driver-class-name: org.elasticsearch.xpack.sql.jdbc.EsDriver
    druid:
      # 是否测试链接
      test-while-idle: false
    mybatis:
      # xml包
      mapper-locations: classpath:esMapper/*Mapper.xml

package com.csj.demo.business.config;
import com.alibaba.druid.pool.DruidDataSource;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import tk.mybatis.spring.annotation.MapperScan;
import javax.sql.DataSource;
/**
 * @Desc : es数据源
 * @Author : chen
 * @Date : 2022/4/26 13:42
 */
@Slf4j
@Configuration
@MapperScan(basePackages = {"com.csj.demo.business.esDao"}, sqlSessionFactoryRef = "esSqlSessionFactory")
public class ESDruidConfig {
    @Value("${spring.esDatasource.url}")
    private String url;
    @Value("${spring.esDatasource.driver-class-name}")
    private String driverClassName;
    @Value("${spring.esDatasource.druid.test-while-idle}")
    private boolean testWhileIdle;
    @Bean(name = "esDataSource")
    public DataSource esDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setTestWhileIdle(testWhileIdle);
        log.info("==============初始化ES DataSource连接"+url+"=================");
        return dataSource;
    }
    @Value("${mybatis.config-location}")
    private String configLocation;
    @Value("${mybatis.type-aliases-package}")
    private String typeAliasesPackage;
    @Value("${spring.esDatasource.mybatis.mapper-locations}")
    private String mapperLocations;
    @Bean("esSqlSessionFactory")
    public SqlSessionFactory esSessionFactory(@Qualifier("esDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(esDataSource());
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations));
        bean.setConfigLocation(new DefaultResourceLoader().getResource(configLocation));
        bean.setTypeAliasesPackage(typeAliasesPackage);
        return bean.getObject();
    }
}