elasticsearch-java api之搜索（二）——聚合_getaggregations

前面一篇文章描述了es一些基本搜索的用法（match、term、fruzzy、matchPhraseQuery等），这篇文章我们着重讲解一下聚合查询的用法。

假设es中有如下数据

1、group by /count：

select team,count(*) from table group by team;

1）代码：

public static void aggre1Query2(String indexName,String indexType) {
		SearchRequestBuilder srb = transportClient.prepareSearch(indexName).setTypes(indexType);
		srb.setSearchType(SearchType.COUNT);
		
		TermsBuilder teamAgg= AggregationBuilders.terms("player_count").field("team");  
		srb.addAggregation(teamAgg);  
		System.out.println(srb.toString());
		
		SearchResponse searchResponse = srb.execute().actionGet();
		Aggregations aggregations = searchResponse.getAggregations();
		Map<String, Aggregation> asMap = aggregations.asMap();
		Terms terms = (Terms)asMap.get("player_count");
		
		List<Bucket> buckets = terms.getBuckets();
		for (Bucket bt : buckets) {
			logger.info(bt.getKeyAsString() + " :: " + bt.getDocCount());
		}
	}

2）输出的dsl：

{
  "aggregations" : {
    "player_count" : {
      "terms" : {
        "field" : "team"
      }
    }
  }
}

3）输出：

[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:461] war :: 3
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:461] cav :: 2
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:461] tim :: 1

2、group by 多个field/count、min、avg：

1）代码：

public static void aggreQuery1(String indexName,String indexType) {
		SearchRequestBuilder srb = transportClient.prepareSearch(indexName).setTypes(indexType);
		srb.setSearchType(SearchType.COUNT);
		
		TermsBuilder teamAgg= AggregationBuilders.terms("team_count").field("team");  
		TermsBuilder positionAgg= AggregationBuilders.terms("position_count").field("position");
		teamAgg.subAggregation(positionAgg);
		
		srb.addAggregation(teamAgg);  
		System.out.println(srb.toString());
		
		SearchResponse searchResponse = srb.execute().actionGet();
		Aggregations aggregations = searchResponse.getAggregations();//team agg
		Terms terms = aggregations.get("team_count");
		List<Bucket> buckets = terms.getBuckets();
		for (Bucket bt : buckets) {
            logger.info(bt.getKeyAsString() + " :: " + bt.getDocCount());
            
            Aggregations aggregations2 = bt.getAggregations();//position agg
            Terms terms2 = aggregations2.get("position_count");
            List<Bucket> buckets2 = terms2.getBuckets();
            for (Bucket bt2 : buckets2) {
            	logger.info("---"+bt2.getKeyAsString() + " :: " + bt2.getDocCount());
            }
        }
}

2）输出的dsl：

{
  "aggregations" : {
    "team_count" : {
      "terms" : {
        "field" : "team"
      },
      "aggregations" : {
        "position_count" : {
          "terms" : {
            "field" : "position"
          }
        }
      }
    }
  }
}

3）输出结果：

[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:430] war :: 3
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---pf :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---pg :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---sg :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:430] cav :: 2
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---pg :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---sf :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:430] tim :: 1
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:436] ---pf :: 1

4）说明：

多个field的groupby 是一层一层的，所以代码中有两个for循环进行输出。

3、查询条件+max/min/sum/avg聚合+排序：

1）代码

public static void aggre1Query3(String indexName,String indexType) {
		boolean min = true;
		boolean avg = true;
		String groupCol = "team";
		
		SearchRequestBuilder srb = transportClient.prepareSearch(indexName).setTypes(indexType);
		srb.setSearchType(SearchType.COUNT);
		
		QueryBuilder qb = QueryBuilders.rangeQuery("age").from(10).to(39);//查询条件
		
		AggregationBuilder aggBuilder= AggregationBuilders.terms("group_name").field(groupCol).order(Order.aggregation("minSalary", false));
		if (min) {
			aggBuilder.subAggregation(AggregationBuilders.min("minSalary").field("salary"));
		}
		if (avg) {
			aggBuilder.subAggregation(AggregationBuilders.avg("avgSalary").field("salary"));
		}
		
		srb.setQuery(qb).addAggregation(aggBuilder);
		System.out.println(srb.toString());
		
		SearchResponse searchResponse = srb.execute().actionGet();
		
		Aggregations aggregations = searchResponse.getAggregations();
		Map<String, Aggregation> asMap = aggregations.asMap();
		Terms terms = (Terms)asMap.get("group_name");
		
		List<Bucket> buckets = terms.getBuckets();
		for (Bucket bt : buckets) {
			logger.info(bt.getKeyAsString() + " :: " + bt.getDocCount());
			
			Aggregations aggregations2 = bt.getAggregations();
			Min minSalary = aggregations2.get("minSalary");
			Avg avgSalary = aggregations2.get("avgSalary");
			logger.info("min:"+minSalary.value()+",avg:"+avgSalary.value());
		}
	}

2）dsl输出：

{
  "query" : {
    "range" : {
      "age" : {
        "from" : 10,
        "to" : 39,
        "include_lower" : true,
        "include_upper" : true
      }
    }
  },
  "aggregations" : {
    "group_name" : {
      "terms" : {
        "field" : "team",
        "order" : {
          "minSalary" : "desc"
        }
      },
      "aggregations" : {
        "minSalary" : {
          "min" : {
            "field" : "salary"
          }
        },
        "avgSalary" : {
          "avg" : {
            "field" : "salary"
          }
        }
      }
    }
  }
}

3）结果输出：

[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:499] cav :: 2
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:504] min:2000.0,avg:2500.0
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:499] war :: 3
[12-05 18:51:32] [INFO] [cn.edu.nuc.EsTest.EsDao4Search:504] min:1000.0,avg:1666.6666666666667

4）说明：

该例子是一个field的groupby，所以代码中只要一个for循环即可；同时获取min和max等聚合项。

4、聚合后返回的条数：

默认情况下，search执行后，仅返回10条聚合结果，如果想反悔更多的结果，需要在构建TermsBuilder 时指定size：

TermsBuilder teamAgg= AggregationBuilders.terms("team").size(15);  

参考：

http://blog.csdn.net/carlislelee/article/details/52598022
http://outofmemory.cn/code-snippet/38461/elasticsearch-aggregation-search-example

http://blog.csdn.net/it_lihongmin/article/details/78447001

http://blog.csdn.net/jacklin929/article/details/70304127