ElasticSearch 6.x 学习笔记：29.Java API之Match All Query

https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.1/java-query-dsl.html
Elasticsearch provides a full Java query dsl in a similar manner to the REST Query DSL. The factory for query builders is QueryBuilders. Once your query is ready, you can use the Search API.
Elasticsearch以类似于REST Query DSL的方式提供完整的Java查询dsl。查询构建器的工厂是QueryBuilders。一旦您的查询准备就绪，您可以使用搜索API。

https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.1/java-query-dsl-match-all-query.html

package cn.hadron;

import cn.hadron.es.ESUtil;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import java.util.Map;

public class MatchAllQuery {
    public static void main(String[] args) {
        TransportClient client = ESUtil.getClient();
        //构造查询对象
        QueryBuilder query= QueryBuilders.matchAllQuery();
        //搜索结果存入SearchResponse
        SearchResponse response=client.prepareSearch("my-index")
                .setQuery(query) //设置查询器
                .setSize(3)      //一次查询文档数
                .get();
        SearchHits hits=response.getHits();
        for(SearchHit hit:hits){
            System.out.println("source:"+hit.getSourceAsString());
            System.out.println("index:"+hit.getIndex());
            System.out.println("type:"+hit.getType());
            System.out.println("id:"+hit.getId());
            //遍历文档的每个字段
            Map<String,Object> map=hit.getSourceAsMap();
            for(String key:map.keySet()){
                System.out.println(key+"="+map.get(key));
            }
            System.out.println("--------------------");
        }
    }
}

  
  
   
   1
   
   2
   
   3
   
   4
   
   5
   
   6
   
   7
   
   8
   
   9
   
   10
   
   11
   
   12
   
   13
   
   14
   
   15
   
   16
   
   17
   
   18
   
   19
   
   20
   
   21
   
   22
   
   23
   
   24
   
   25
   
   26
   
   27
   
   28
   
   29
   
   30
   
   31
   
   32
   
   33
   
   34
   
   35
   
   36
   
   37

执行结果

no modules loaded 

loaded plugin [org.elasticsearch.index.reindex.ReindexPlugin] 

loaded plugin [org.elasticsearch.join.ParentJoinPlugin] 

loaded plugin [org.elasticsearch.percolator.PercolatorPlugin] 

loaded plugin [org.elasticsearch.script.mustache.MustachePlugin] 

loaded plugin [org.elasticsearch.transport.Netty4Plugin] 

source:{ 

  “name”:“程裕强”, 

  “age”:31, 

  “gender”:“男”, 

  “salary”:20000, 

  “dep”:“bigdata” 

}

index:my-index
type:persion
id:5
gender=男
name=程裕强
salary=20000
age=31

dep=bigdata

source:{
“name”:“李四”,
“age”:26,
“gender”:“女”,
“salary”:15000,
“dep”:“bigdata”
}

index:my-index
type:persion
id:2
gender=女
name=李四
salary=15000
age=26

dep=bigdata

source:{
“name”:“刘六”,
“age”:27,
“gender”:“女”,
“salary”:18000,
“dep”:“AI”
}

index:my-index
type:persion
id:4
gender=女
name=刘六
salary=18000
age=27

dep=AI

Process finished with exit code 0