ElastaticSearch学习笔记(四) ----- es常用的java api

DSL：

首先是es的DSL语句：

GET index名称/type名称/_search
{
  "size" : 10000,
  "query" : {
    "bool" : {
      "must" : [
        {
          "range" : {
            "范围查询字段" : {
              "from" : "2020-10-24",
              "to" : "2020-10-30"
            }
          }
        },
        {
          "term" : {
            "查询字段" : {
              "value" : "匹配值"
            }
          }
        },
        {
          "exists" : {
            "field" : "是否存在字段"
          }
        }
      ]
    }
  }
  
  
}  

对应的java代码如下：

        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(10000);
        BoolQueryBuilder bollQuery = QueryBuilders.boolQuery();
        // bollQuery.filter(QueryBuilders.termQuery(过滤字段,匹配值));
        bollQuery.must(QueryBuilders.termQuery(查询字段,匹配值));
        bollQuery.must(QueryBuilders.existsQuery(是否存在字段,匹配值));
        bollQuery.must(QueryBuilders.rangeQuery(范围查询字段).from(开始).to(结束));

        String dsl = searchSourceBuilder.query(bollQuery).toString();

聚合：

• 聚合统计：

聚合的语句，示例如下：

GET index名称/type名称/_search
{
  "size" : 0,
  "query" : {
    "bool" : {
      "filter" : [
        {
          "term" : {
            "过滤字段1" : {
              "value" : "匹配值"
            }
          }
        },
        {
          "term" : {
            "过滤字段2" : {
              "value" : "匹配值"
            }
          }
        }
      ]
    }
  },
  "aggregations" : {
    "自已命令的聚合名称1" : {
      "terms" : {
        "field" : "聚合分组字段",
        "size" : 10000,
        "order" : {
          "排序字段" : "asc"
        }
      },
      "aggregations" : {
        "自已命令的聚合名称2" : {
          "sum" : {
            "field" : "聚合求和字段"
          }
        }
      }
    }
  }
}

对应的java代码如下：

        //只聚合求结果，不需要查询结果
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(0);
        BoolQueryBuilder bollQuery = QueryBuilders.boolQuery();
        bollQuery.filter(QueryBuilders.termQuery(过滤字段1,匹配值));
        bollQuery.filter(QueryBuilders.termQuery(过滤字段2,匹配值));

        TermsAggregationBuilder termsAggregation = AggregationBuilders.terms(自己命名的聚合名称).field(聚合分组字段)
                .order(Terms.Order.aggregation(排序字段, false)).size(10000)
                .subAggregation(AggregationBuilders.sum(自己命名的聚合求和名称).field(聚合求和字段))
                .subAggregation(AggregationBuilders.max(自己命名的聚合求最大值名称).field(聚合求最大值字段));
        searchSourceBuilder.aggregation(termsAggregation);

        String aggregation = searchSourceBuilder.query(bollQuery).toString();

通过聚合查询后返回的结果 returnDataStr，使用fastjson解析，代码如下：

            JSONObject returnDataJson = JSON.parseObject(returnDataStr);
            JSONObject aggregations = returnDataJson.getJSONObject(AGGREGATIONS).getJSONObject(聚合分组字段);
            JSONArray bucketsArray = aggregations.getJSONArray(BUCKETS);
            for (Object bucket : bucketsArray) {
                JSONObject bucketJson = (JSONObject) bucket;
                String key = bucketJson.getString(KEY);
                JSONObject numJson = bucketJson.getJSONObject(聚合字段);
                int num =0;
                if (numJson != null && numJson.getBigDecimal(VALUE)!=null) {
                    num = numJson.getBigDecimal(VALUE).intValue();
                }

            }

• script：

多字段分组或者组合、比较，可以使用script。

查询语句如下：

 {
  "size" : 0,
  "query" : {
	 "bool" : {
      "filter" : [
        {
          "term" : {
            "过滤字段1" : {
              "value" : "匹配值"
            }
          }
        },
        {
          "term" : {
            "过滤字段2" : {
              "value" : "匹配值"
            }
          }
        }
      ]
	}
  }
  ,"aggregations" : {
    "聚合名称" : {
      "terms" : {
        "script" : {
          "inline" : "doc['字段名称1'].values +'-'+ doc['字段名称2'].values",
          "lang" : "painless"
        },
        "size" : 10000,
        "order" : {
          "排序字段" : "desc"
        }
      },
      "aggregations" : {
        "自已命令的聚合名称" : {
          "sum" : {
            "field" : "聚合求和字段"
          }
        }
      }
    }
  }
 }      

对应的java代码如下：

        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().size(0);
        BoolQueryBuilder bollQuery = QueryBuilders.boolQuery();
        bollQuery.filter(QueryBuilders.termQuery(过滤字段,匹配值));      
 
        String idOrCode = "doc['"+字段名称+"'].values +'-'+ doc['"+字段名称+"'].values";
        Script script = new Script(idOrCode);

        TermsAggregationBuilder termsAggregation = AggregationBuilders.terms(自己命名的聚合名称).script(script)
                .order(Terms.Order.aggregation(排序字段, false)).size(10000)
                .subAggregation(AggregationBuilders.sum(自己命名的聚合求和名称).field(聚合求和字段))
                .subAggregation(AggregationBuilders.max(自己命名的聚合求最大值名称).field(聚合求最大值字段));
        searchSourceBuilder.aggregation(termsAggregation);

        String aggregation = searchSourceBuilder.query(bollQuery).toString();