使用jestClient查询ES常见问题

使用jestClient查询ES常见问题

使用JestClient快速查询ES

众所周知，ES提供连接的方法有两种，一种是HTTP请求方式，一种是TCP/IP方式，ES对这两种方式提供了不同的接口，可以在ES的配置文件中查看详细端口号，在此不在赘述。
现在微服务的全家桶来说，基于spring boot和spring cloud很多情况下需要使用ES中间件进行存储一些数据或者是实现一些功能，比如分词、改造队列等等。所以spring也有相应的spring-data-ElasticSeach组件包连接ES进行相应的操作，其底层是使用了TCP/IP进行连接的，因为ES之后的版本TCP/IP的连接方式将不再支持，所以我们对新版本的ES使用JestClient进行连接。

开始我们的查询旅途吧~
首先加入我们的jestClient和ES的依赖

		<dependency>
            <groupId>io.searchbox</groupId>
            <artifactId>jest</artifactId>
            <version>5.3.4</version>
        </dependency>
		<dependency>
			<groupId>org.elasticsearch</groupId>
			<artifactId>elasticsearch</artifactId>
            <version>6.3.2</version>
		</dependency>

指定我们的ES服务地址，当然是http连接的端口地址

spring.elasticsearch.jest.uris=http://127.0.0.1:9200

接下来我们写一个简单精确查询的例子，注意如果是要查询英文，所传入的值应该做小写处理，不然搜不到

import io.searchbox.client.JestClient;
import io.searchbox.client.JestResult;
import io.searchbox.core.Search;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.IOException;

public class test {
    @Autowired
    JestClient jestClient;

    public void seach() throws IOException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.termQuery("字段名","123"));
        Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }
}

然后使用jestResult获取各种你想要的查询值

要想改变搜索条件，那么参考下面的方法

模糊搜索，*为通配符

public void seach() throws IOException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.wildcardQuery("字段名","*123*"));
        Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

模糊搜索+分页请求，使用方法类似于sql里的limit

public void seach() throws IOException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.wildcardQuery("字段名","*123*"));
        searchSourceBuilder.from(0).size(10);
        Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

搜索排序，其中排序方法使用org.elasticsearch.search.sort.SortOrder里的方法

public void seach() throws IOException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.wildcardQuery("字段名","*123*"));
        searchSourceBuilder.from(0).size(10).sort("排序字段名", SortOrder.DESC);
        Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

区间查询，其中rangeQuery也可只传起始值，或者只传终值，就是大于小于的意思

public void seach() throws IOException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.rangeQuery("字段名").from("起始值").to("终值"));
        Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

多重条件查询，在这里就需要注意了，我们往往会遇到多种条件一起查询的场景。由于每一次调用SearchSourceBuilder的query方法都会进行重新覆盖对象，也就是说SearchSourceBuilder只会使用最后一次query方法获取的查询语句，所以当多重条件执行的时候使用boolQueryBuilder的must函数进行条件的拼接可以完美解决这个问题。

 public void Search(String id,String phone, Date startTime, Date endTime, Integer pageNum, Integer pageSize) throws ParseException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();
        if (id!=null){
            boolQueryBuilder.must(QueryBuilders.termQuery("id", id.toLowerCase()));
        }
        if (phone!=null){
            boolQueryBuilder.must(QueryBuilders.wildcardQuery("phone","*"+phone+"*"));
        }
        if (startTime!=null||endTime!=null){
        boolQueryBuilder.must(QueryBuilders.rangeQuery("DateTime").from(startTime).to(endTime));
        }
        if (pageNum!=null&&pageNum!=0){
            searchSourceBuilder.from((pageNum-1)*pageSize).size(pageSize).sort("DateTime", SortOrder.DESC);
        }
        searchSourceBuilder.query(boolQueryBuilder);
     	Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

因为ES的特殊性，我们往往查询的时候会查出很多数据，所以ES在不加入size的查询请求时只会默认返回10条数据，所以我们一般查询指定条件的时候都会加上限制个数(size)的条件.

根据phone字段去重查询

 public void Search(String id,String phone, Date startTime, Date endTime, Integer pageNum, Integer pageSize) throws ParseException {
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        BoolQueryBuilder boolQueryBuilder = new BoolQueryBuilder();
        if (id!=null){
            boolQueryBuilder.must(QueryBuilders.termQuery("id", id.toLowerCase()));
        }
        if (phone!=null){
            boolQueryBuilder.must(QueryBuilders.wildcardQuery("phone","*"+phone+"*"));
        }
        if (startTime!=null||endTime!=null){
        boolQueryBuilder.must(QueryBuilders.rangeQuery("DateTime").from(startTime).to(endTime));
        }
        if (pageNum!=null&&pageNum!=0){
            searchSourceBuilder.from((pageNum-1)*pageSize).size(pageSize).sort("DateTime", SortOrder.DESC);
        }
        searchSourceBuilder.query(boolQueryBuilder);
        searchSourceBuilder.aggregation(AggregationBuilders.cardinality("phone_aggs").field("phone.keyword"));
    	Search search =new Search.Builder(searchSourceBuilder.toString()).addIndex("索引名").addType("type名").build();
        JestResult jestResult = jestClient.execute(search);
    }

看到这里你应该对通过jestClient查询ES小有心得了，快去实现吧。