【ES】[教程]----第三章：Elasticsearch 用 Java API操作（索引、文档、高级查询）
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1、创建Maven项目
Elasticsearch软件是由Java语言开发的，所以也可以通过Java API的方式对Elasticsearch服务进行访问
修改pom文件，增加Maven依赖关系
<dependencies>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>7.8.0</version>
</dependency>
<!-- elasticsearch的客户端 -->
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.8.0</version>
</dependency>
<!-- elasticsearch依赖2.x的log4j -->
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.8.2</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.8.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.9</version>
</dependency>
<!-- junit单元测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
2、客户端对象
创建com.zhuguanbo.es.test.Elasticsearch01_Client类，代码中创建Elasticsearch客户端对象
因为早期版本的客户端对象已经不再推荐使用，且在未来版本中会被删除，所以这里我们采用高级REST客户端对象
// 创建客户端对象
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost", 9200, "http"))
);
...
// 关闭客户端连接
client.close();
注意：9200端口为Elasticsearch的Web通信端口，localhost为启动ES服务的主机名
3、【索引 Index】操作
1) 创建–索引
// 创建索引 - 请求对象
CreateIndexRequest request = new CreateIndexRequest("user");
// 发送请求，获取响应
CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
boolean acknowledged = response.isAcknowledged();
// 响应状态
System.out.println("操作状态 = " + acknowledged); // 操作状态 = true
1) 查看–索引
// 查询索引 - 请求对象
GetIndexRequest request = new GetIndexRequest("user");
// 发送请求，获取响应
GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
System.out.println("aliases:"+response.getAliases());
System.out.println("mappings:"+response.getMappings());
System.out.println("settings:"+response.getSettings());
--------------------------------------------------------------------------------------------------------------------------------
操作结果:
aliases:{user=[]}
mappings:{user=org.elasticsearch.cluster.metadata.MappingMetadata@e1ec094b}
settings:{user={"index.creation_date":"1614527311782","index.number_of_replicas":"1","index.number_of_shards":"1","index.
2) 删除–索引
// 删除索引 - 请求对象
DeleteIndexRequest request = new DeleteIndexRequest("user");
// 发送请求，获取响应
AcknowledgedResponse response = client.indices().delete(request, RequestOptions.DEFAULT);
// 操作结果
System.out.println("操作结果 ： " + response.isAcknowledged());
操作结果:true
4、【文档】操作
1) 新增–文档
====================================================================================
class User { //创建数据模型 get set 方法 .....
private String name;
private Integer age;
private String sex;
}
====================================================================================
创建数据，添加到文档中
// 新增文档 - 请求对象
IndexRequest request = new IndexRequest();
// 设置索引及唯一性标识
request.index("user").id("1001");
// 创建数据对象
User user = new User("zhangsan",30,"男");
ObjectMapper objectMapper = new ObjectMapper();
String productJson = objectMapper.writeValueAsString(user);
// 添加文档数据，数据格式为JSON格式
request.source(productJson,XContentType.JSON);
// 客户端发送请求，获取响应对象
IndexResponse response = client.index(request, RequestOptions.DEFAULT);
////3.打印结果信息
System.out.println("_index:" + response.getIndex());
System.out.println("_id:" + response.getId());
System.out.println("_result:" + response.getResult());
-----------------------------------------------------------------------------------
操作结果:
_index:user
_id:1001
_result:CREATED
2) 修改–文档
=============================================================================================
// 修改文档 - 请求对象
UpdateRequest request = new UpdateRequest();
// 配置修改参数
request.index("user").id("1001");
// 设置请求体，对数据进行修改
request.doc(XContentType.JSON, "sex", "女");
// 客户端发送请求，获取响应对象
UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
System.out.println("_index:" + response.getIndex());
System.out.println("_id:" + response.getId());
System.out.println("_result:" + response.getResult());
-----------------------------------------------------------------------------------
操作结果:
_index:user
_id:1001
_result:UPDATED
3) 查询–文档
=============================================================================================
//1.创建请求对象
GetRequest request = new GetRequest().index("user").id("1001");
//2.客户端发送请求，获取响应对象
GetResponse response = client.get(request, RequestOptions.DEFAULT);
////3.打印结果信息
System.out.println("_index:" + response.getIndex());
System.out.println("_type:" + response.getType());
System.out.println("_id:" + response.getId());
System.out.println("source:" + response.getSourceAsString());
----------------------------------------------------------------------------------------------
执行结果为：
_index:user
_type:_doc
_id:10001
source:{"name":"zhangsan","age":30,"sex":"女"}
4) 删除–文档
=============================================================================================================================
//创建请求对象
DeleteRequest request = new DeleteRequest().index("user").id("1");
//客户端发送请求，获取响应对象
DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
//打印信息
System.out.println(response.toString());
-------------------------------------------------------------------------------------------------------------------------------
执行结果为：
DeleteResponse[index=user,type=_doc,id=10001,version=3,result=deleted,shards=ShardInfo{total=2,successful=1,failures=[]}]
5) 批量–操作
批量新增：
===============================================================================================================================
//创建批量新增请求对象
BulkRequest request = new BulkRequest();
request.add(new IndexRequest().index("user").id("1001").source(XContentType.JSON, "name", "zhangsan"));
request.add(new IndexRequest().index("user").id("1002").source(XContentType.JSON, "name", "lisi"));
request.add(new IndexRequest().index("user").id("1003").source(XContentType.JSON, "name", "wangwu"));
//客户端发送请求，获取响应对象
BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
//打印结果信息
System.out.println("took:" + responses.getTook());
System.out.println("items:" + responses.getItems());
-------------------------------------------------------------------------------------------------------------------------------
执行结果为：
took:12ms
items:Fluent elasticsearch action hulk BulkItemResponse:03e0964harf
批量删除：
===============================================================================================================================
//创建批量删除请求对象
BulkRequest request = new BulkRequest();
request.add(new DeleteRequest().index("user").id("1001"));
request.add(new DeleteRequest().index("user").id("1002"));
request.add(new DeleteRequest().index("user").id("1003"));
//客户端发送请求，获取响应对象
BulkResponse responses = client.bulk(request, RequestOptions.DEFAULT);
//打印结果信息
System.out.println("took:" + responses.getTook());
System.out.println("items:" + responses.getItems());
-------------------------------------------------------------------------------------------------------------------------------
执行结果为：
took:10ms
items:[Lorg.elasticsearch.action.bulk.BulkItemResponse;@6913c1f6
5、【高级查询】
1) 请求体查询
1 查询所有索引
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
// 查询所有数据
sourceBuilder.query(QueryBuilders.matchAllQuery());
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
2 term查询，查询条件为关键字
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.termQuery("age", "30"));
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
3 分页查询
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchAllQuery());
// 分页查询
// 当前页其实索引(第一条数据的顺序号)，from
sourceBuilder.from(0);
// 每页显示多少条size
sourceBuilder.size(2);
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
------------------------------------------------------------------------------------------------------
took:0ms
timeout:false
total:5 hits
MaxScore:1.0
hits=========
{"name":"zhangsan","nickname":"zhangsan","sex":"男","age":30}
{"name":"Lisi","nickname":"Lisi","sex":"男","age":20}
<<<<<<<<<<
4 数据排序
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchAllQuery());
//================排序================
sourceBuilder.sort("age", SortOrder.ASC);
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
----------------------------------------------------------------------------------------------
输出结果：
timeout:false
total:5 hits
MaxScore:NaN
hits=========
{"name":"lisi","nickname":"lisi","sex":"男","age":20}
{"name":"zhangsan","nickname":"zhangsan","sex":"男","age":30}
{"name":"zhangsan2","nickname":"zhangsan2","sex":"女","age":30}
{"name":"wangwu","nickname":"wangwu","sex":"女","age":40}
{"name":"zhangsan1","nickname":"zhangsan1","sex":"女","age":50}
<<========
5 过滤字段
-------------------------------------------------------------------------------------------------
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.matchAllQuery());
//================查询字段过滤================
String[] excludes = {};
String[] includes = {"name", "age"};
sourceBuilder.fetchSource(includes, excludes);
//================查询字段过滤================
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
-------------------------------------------------------------------------------------------------
输出结果：
took:1ms
timeout:false
totalHits:5
MaxScore:1.0
hits:-----
{"name":"zhangsansan","age":30}
{"name":"lisi","age":20}
{"name":"wangwu","age":40}
{"name":"zhangsan1","age":50}
{"name":"zhangsan2","age":30}
6 Bool查询
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
//===============================
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
// 必须包含
boolQueryBuilder.must(QueryBuilders.matchQuery("age", "30"));
// 一定不含
boolQueryBuilder.mustNot(QueryBuilders.matchQuery("name", "zhangsan"));
// 可能包含
boolQueryBuilder.should(QueryBuilders.matchQuery("sex", "男"));
//===============================
sourceBuilder.query(boolQueryBuilder);
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
---------------------------------------------------------------------------------------------
took:1ms
timeout:false
hits
total:1
hits:1
maxScore:1.0
hits======>>
{"name":"zhangsan2","nickname":"zhangsan2","sex":"女","age":30}
<<==========
7 范围查询
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
//===================================
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
RangeQueryBuilder rangeQuery = QueryBuilders.rangeQuery("age");
// 大于等于
rangeQuery.gte("30");
// 小于等于
rangeQuery.lte("40");
//===================================
sourceBuilder.query(rangeQuery);
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
---------------------------------------------------------------------------------------------
took:2ms
timeout:false
total:3
hits:3
MaxScore:3
[
{"name":"zhangsan","nickname":"zhangsan","sex":"男","age":30},
{"name":"wangwu","nickname":"wangwu","sex":"女","age":40},
{"name":"zhangsan2","nickname":"zhangsan2","sex":"女","age":30}
]
8 模糊查询
// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
// 构建查询的请求体
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.query(QueryBuilders.fuzzyQuery("name","zhangsan").fuzziness(Fuzziness.ONE));
request.source(sourceBuilder);
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
// 查询匹配
SearchHits hits = response.getHits();
System.out.println("took:" + response.getTook());
System.out.println("timeout:" + response.isTimedOut());
System.out.println("total:" + hits.getTotalHits());
System.out.println("MaxScore:" + hits.getMaxScore());
System.out.println("hits========>>");
for (SearchHit hit : hits) {
//输出每条查询的结果信息
System.out.println(hit.getSourceAsString());
}
System.out.println("<<========");
------------------------------------------------------------------------
took:2ms
timeout:false
total:3
hits:1.0.1.0296195
hits=========
{"name":"zhangsan","nickname":"zhangsan","sex":"男","age":30}
{"name":"zhangsan1","nickname":"zhangsan1","sex":"女","age":50}
{"name":"zhangsan2","nickname":"zhangsan2","sex":"女","age":30}
2) 高亮查询
// 高亮查询
SearchRequest request = new SearchRequest().indices("student");
//2.创建查询请求体构建器
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构建查询方式：高亮查询
TermsQueryBuilder termsQueryBuilder = QueryBuilders.termsQuery("name","zhangsan");
//设置查询方式
sourceBuilder.query(termsQueryBuilder);
//构建高亮字段
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.preTags("<font color='red'>");//设置标签前缀
highlightBuilder.postTags("</font>");//设置标签后缀
highlightBuilder.field("name");//设置高亮字段
//设置高亮构建对象
sourceBuilder.highlighter(highlightBuilder);
//设置请求体
request.source(sourceBuilder);
//3.客户端发送请求，获取响应对象
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//4.打印响应结果
SearchHits hits = response.getHits();
System.out.println("took::"+response.getTook());
System.out.println("time_out::"+response.isTimedOut());
System.out.println("total::"+hits.getTotalHits());
System.out.println("max_score::"+hits.getMaxScore());
System.out.println("hits::::>>");
for (SearchHit hit : hits) {
String sourceAsString = hit.getSourceAsString();
System.out.println(sourceAsString);
//打印高亮结果
Map<String, HighlightField> highlightFields = hit.getHighlightFields();
System.out.println(highlightFields);
}
System.out.println("<<::::");
------------------------------------------------
took:3ms
timeout:false
total::1
max_score:1.0
hits::>>>>
{"name":"zhangsan","nickname":"zhangsan","sex":"男","age":30}
{#name=[name], fragments[[zhangsan]]}
<<<<:::
3) 聚合查询
1 最大年龄
// 高亮查询
SearchRequest request = new SearchRequest().indices("student");
//================================
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.aggregation(AggregationBuilders.max("maxAge").field("age"));
//================================
//设置请求体
request.source(sourceBuilder);
//3.客户端发送请求，获取响应对象
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//4.打印响应结果
SearchHits hits = response.getHits();
System.out.println(response);
2 分组统计
// 高亮查询
SearchRequest request = new SearchRequest().indices("student");
//===========================
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.aggregation(AggregationBuilders.terms("age_groupby").field("age"));
//===========================
//设置请求体
request.source(sourceBuilder);
//3.客户端发送请求，获取响应对象
SearchResponse response = client.search(request, RequestOptions.DEFAULT);
//4.打印响应结果
SearchHits hits = response.getHits();
System.out.println(response);
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