- ElasticSearch基础知识
- es是什么
- 启动es
- 常见问题
- 客户端安装
- 数据格式
- 索引操作
- 索引查询和删除
- 文档创建
- 数据的修改
- 全量修改
- 局部修改
- 删除操作
- 查询操作
- 条件查询
- 分页查询
- 查询排序
- 多条件查询
- 全文检索、完全匹配、高亮查询
- 全文检索
- 完全匹配
- 高亮查询
- 聚合查询
- 映射关系
- 创建映射
- 体现映射效果
- java api操作es
- 环境准备
- 创建连接
- 创建索引
- 索引查询
- 索引删除
- 索引添加数据
- 索引修改
- 查询某条数据
- 删除某条数据
- 批量新增
- 批量删除
学习地址：尚硅谷
看到第24集
访问
1.ElasticsearchException[X-Pack is not supported and Machine Learning is not available for
解决：在config/elasticsearch.yml添加一条配置：
xpack.ml.enabled: false客户端安装 数据格式
倒排索引和正排索引
索引创建过程
PUT请求具有密等性
查询
查看创建的所有索引的信息
访问地址：
http://localhost:9200/_cat/indices?v
删除索引
创建文档
创建自己的文档id
查询索引中指定id的数据
查询索引下的所有数据
测试数据
{
"title":"es的学习",
"name":"hjx",
"time":"2021-12-23"
}
全量修改
局部修改
删除操作
查询操作
条件查询
http://localhost:9200/shopping/_search?q=price:100
上面这种查询方式不方便（因为查询条件是在url中的，下面这种将查询条件放入请求体中）
使用请求体全部查询
from：表示当前页数据的起始位置
size:每页查询的数据条数
显示指定字段的数据
注意：这里的must相当于mysql中的and 连接符
{
"query":{
"bool":{
"must":[
{
"match":{
"price":23
}
},
{
"match":{
"title":"JSP入门"
}
},
]
}
}
}
或查询
范围查询
注意：这种查询方式会将含有其中一个词的数据的每条数据都查询出来
查询平均值
创建连接org.elasticsearch elasticsearch 7.11.2 org.elasticsearch.client elasticsearch-rest-high-level-client 7.11.2 org.apache.logging.log4j log4j-api 2.10.0 com.fasterxml.jackson.core jackson-databind 2.9.9.3 junit junit 4.12 test
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
client.close();
创建索引
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
// 创建索引
CreateIndexRequest request=new CreateIndexRequest("fruit"); // 索引名称
CreateIndexResponse response =client.indices().create(request, RequestOptions.DEFAULT);
// 响应状态
boolean acknowledged=response.isAcknowledged();
System.out.println("索引操作："+acknowledged);
client.close();
索引查询
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
// 查询索引
GetIndexRequest request=new GetIndexRequest("fruit");
GetIndexResponse response=client.indices().get(request, RequestOptions.DEFAULT);
// 响应状态
System.out.println(response.getAliases());
System.out.println(response.getMappings());
System.out.println(response.getSettings());
索引删除
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
// 查询索引
DeleteIndexRequest request=new DeleteIndexRequest("fruit");
AcknowledgedResponse response=client.indices().delete(request, RequestOptions.DEFAULT);
// 响应状态
System.out.println(response.isAcknowledged());入代码片
索引添加数据
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
// 插入数据
IndexRequest request=new IndexRequest();
request.index("fruit").id("101");
// 设置对象数据
Fruit fruit=new Fruit();
// fruit.setId();
fruit.setName("苹果");
fruit.setPrice(5.5);
fruit.setColor("yellow");
// client.index(request, RequestOptions.DEFAULT);
// 注意：将数据插入之前，必须转换为json
ObjectMapper objectMapper=new ObjectMapper();
String fruit_json=objectMapper.writevalueAsString(fruit);
request.source(fruit_json, XContentType.JSON);
IndexResponse response=client.index(request,RequestOptions.DEFAULT);
System.out.println(response.getResult());
// 关闭资源
client.close();
索引修改
局部数据修改
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
// 修改数据
UpdateRequest request=new UpdateRequest();
request.index("fruit").id("101");
request.doc(XContentType.JSON,"name","橘子");
UpdateResponse response=client.update(request, RequestOptions.DEFAULT);
System.out.println("响应状态:"+response.getResult());
查询某条数据
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
GetRequest request=new GetRequest();
request.index("fruit").id("101");
GetResponse response=client.get(request,RequestOptions.DEFAULT);
System.out.println(response.getSourceAsString());
删除某条数据
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
DeleteRequest request=new DeleteRequest();
request.index("fruit").id("101");
DeleteResponse response=client.delete(request, RequestOptions.DEFAULT);
System.out.println(response);
// 关闭资源
client.close();
批量新增
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
BulkRequest request=new BulkRequest();
Fruit fruit1=new Fruit();
fruit1.setName("黄瓜");
fruit1.setPrice(5);
fruit1.setColor("green");
Fruit fruit2=new Fruit();
fruit2.setName("西红柿");
fruit2.setPrice(3);
fruit2.setColor("red");
Fruit fruit3=new Fruit();
fruit3.setName("橙子");
fruit3.setPrice(8.7);
fruit3.setColor("yellow");
request.add(new IndexRequest().index("fruit").id("101").source(XContentType.JSON,"name","西红柿","price",3, "color","red"));
request.add(new IndexRequest().index("fruit").id("102").source(XContentType.JSON,"name","黄瓜","price",5, "color","green"));
request.add(new IndexRequest().index("fruit").id("103").source(XContentType.JSON,"name","橙子","price",8.7, "color","yellow"));
BulkResponse response=client.bulk(request, RequestOptions.DEFAULT);
System.out.println(response.getTook());
System.out.println(response.getItems());
client.close();
批量删除
// 创建es客户端
RestHighLevelClient client=new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost",9200,"http"))
);
BulkRequest request=new BulkRequest();
// request.add(new DeleteRequest().index("fruit").id("101"));
request.add(new DeleteRequest().index("fruit").id("102"));
request.add(new DeleteRequest().index("fruit").id("103"));
BulkResponse response=client.bulk(request, RequestOptions.DEFAULT);
System.out.println(response.getTook());
System.out.println(response.getItems());
client.close();
