---

前言

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

导入依赖

注意点：导入依赖的版本一定要和自己安装ES版本一致！！！

<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>

客户端对象

连接ES服务器

@Configuration
public class GulimallESConfig {

    public static final RequestOptions COMMON_OPTIONS;

    static {
        RequestOptions.Builder builder = RequestOptions.DEFAULT.toBuilder();

        COMMON_OPTIONS = builder.build();
    }

    @Bean
    public RestHighLevelClient esRestClint(){
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(new HttpHost("192.168.40.128", 9200, "http"))
        );
        return client;
    }

}

注意：9200 端口为 Elasticsearch 的 Web 通信端口，localhost 为启动 ES 服务的主机名执行代码，查看控制台信息

索引操作

ES 服务器正常启动后，可以通过 Java API 客户端对象对 ES 索引进行操作

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);

2. 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());

3. 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());

文档操作

1. 新增文档

   创建数据模型

class User { 
 private String name; 
 private Integer age; 
 private String sex; 
 
 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 getSex() { 
 return sex; 
 } 
 public void setSex(String sex) { 
 this.sex = 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();
user.setName("zhangsan");
user.setAge(30);
user.setSex("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());

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());

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());

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());

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());

• 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());

高级查询

1. 请求体查询

查询所有索引数据

// 创建搜索请求对象
SearchRequest request = new SearchRequest();
request.indices("student");
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("<<========");
// 构建查询的请求体

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("<<========");

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("<<========");

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("<<========");

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);
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("<<========");

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("<<========")

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("<<========");

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(Fu
zziness.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("<<========");

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("<<::::");

3.聚合查询

// 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);

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("ag
e"));
//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);