ElasticSearch 6.x 学习笔记：33.Java API之指标聚合

0、自定义工具类

https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.1/java-aggs.html

To build aggregation requests, use AggregationBuilders helpers. Just import them in your class:

import org.elasticsearch.search.aggregations.AggregationBuilders;

package cn.hadron.es;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.search.aggregations.AggregationBuilder;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.aggregations.metrics.cardinality.Cardinality;
import org.elasticsearch.search.aggregations.metrics.max.Max;
import org.elasticsearch.search.aggregations.metrics.min.Min;
import org.elasticsearch.search.aggregations.metrics.percentiles.Percentiles;
import org.elasticsearch.search.aggregations.metrics.stats.Stats;
import org.elasticsearch.search.aggregations.metrics.stats.extended.ExtendedStats;
import org.elasticsearch.search.aggregations.metrics.sum.Sum;
import org.elasticsearch.search.aggregations.metrics.valuecount.ValueCount;
public class AggregationUtil {
private String index="index";
private TransportClient client = ESUtil.getClient();

public AggregationUtil(String index){
this.index=index;
}
...
...
}

https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.1/_metrics_aggregations.html

1、max统计

/**
* 最大值统计
* @param field
* @return
*/
public double max(String field){
AggregationBuilder agg=AggregationBuilders.max("aggMax").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).get();
Max max=response.getAggregations().get("aggMax");
return max.getValue();
}

2、min统计

/**
* 最小值统计
* @param field
* @return
*/
public double min(String field){
AggregationBuilder agg=AggregationBuilders.min("aggMin").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).get();
Min min=response.getAggregations().get("aggMin");
return min.getValue();
}

3、sum统计

/**
* 合计统计
* @param field
* @return
*/
public double sum(String field){
AggregationBuilder agg=AggregationBuilders.sum("aggSum").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).get();
Sum sum=response.getAggregations().get("aggSum");
return sum.getValue();
}

4、avg统计

/**
* 平均值统计
* @param field
* @return
*/
public double avg(String field){
AggregationBuilder agg=AggregationBuilders.avg("aggAvg").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).get();
Avg avg=response.getAggregations().get("aggAvg");
return avg.getValue();
}

5、基本统计

/**
* 基本统计
* @param field
* @return
*/
public Stats stats(String field){
AggregationBuilder agg=AggregationBuilders.stats("aggStats").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).execute().actionGet();
return response.getAggregations().get("aggStats");
}

6、高级统计

/**
* 高级统计
* @param field
* @return
*/
public ExtendedStats extendedStats(String field){
AggregationBuilder agg=AggregationBuilders.extendedStats("exStats").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).execute().actionGet();
return response.getAggregations().get("exStats");
}

7、基数统计

/**
* 基数统计
* @param field
* @return
*/
public double cardinality(String field){
AggregationBuilder agg=AggregationBuilders.cardinality("cardinality").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).get();
Cardinality c=response.getAggregations().get("cardinality");
return c.getValue();
}

8、百分位统计

/**
* 百分位统计
* @param field
* @return
*/
public Percentiles percentiles(String field){
AggregationBuilder agg=AggregationBuilders.percentiles("percentiles").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).execute().actionGet();
return response.getAggregations().get("percentiles");
}

9、文档数量统计

/**
* 文档数量统计
* @param field
* @return
*/
public double valueCount(String field){
AggregationBuilder agg=AggregationBuilders.count("valueCount").field(field);
SearchResponse response=client.prepareSearch(index).addAggregation(agg).execute().actionGet();
ValueCount count=response.getAggregations().get("valueCount");
return count.getValue();
}

10、测试样例

（1）max

package cn.hadron;
import cn.hadron.es.AggregationUtil;
public class AggregationDemo {
public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double max=util.max("age");
System.out.println("max age="+max);
}
}

max age=31.0

（2）min

public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double min=util.min("salary");
System.out.println("min salary="+min);
}

min salary=15000.0

（3）avg

public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double avg=util.avg("salary");
System.out.println("avg salary="+avg);
}

avg salary=17500.0

（4）sum

public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double sum=util.sum("salary");
System.out.println("sum salary="+sum);
}

sum salary=105000.0

（5）stats

package cn.hadron;
import cn.hadron.es.AggregationUtil;
import org.elasticsearch.search.aggregations.metrics.stats.Stats;

public class AggregationDemo {
public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
Stats stats=util.stats("salary");
System.out.println("min="+stats.getMin());
System.out.println("max="+stats.getMax());
System.out.println("avg="+stats.getAvg());
System.out.println("sum="+stats.getSum());
System.out.println("count="+stats.getCount());
}
}

min=15000.0
max=20000.0
avg=17500.0
sum=105000.0
count=6

（6）extendedStats

package cn.hadron;
import cn.hadron.es.AggregationUtil;
import org.elasticsearch.search.aggregations.metrics.stats.extended.ExtendedStats;
public class AggregationDemo {
public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
ExtendedStats stats=util.extendedStats("salary");
System.out.println("min="+stats.getMin());
System.out.println("max="+stats.getMax());
System.out.println("avg="+stats.getAvg());
System.out.println("sum="+stats.getSum());
System.out.println("count="+stats.getCount());
System.out.println("stdDeviation="+stats.getStdDeviation());
System.out.println("sumOfSquares="+stats.getSumOfSquares());
System.out.println("variance="+stats.getVariance());
}
}

min=15000.0
max=20000.0
avg=17500.0
sum=105000.0
count=6
stdDeviation=2061.5528128088304
sumOfSquares=1.863E9
variance=4250000.0

（7）cardinality

public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double cardinality=util.cardinality("salary");
System.out.println("cardinality="+cardinality);
}

4个工资级别

cardinality=4.0

（8）percentiles

package cn.hadron;
import cn.hadron.es.AggregationUtil;
import org.elasticsearch.search.aggregations.metrics.percentiles.Percentile;
import org.elasticsearch.search.aggregations.metrics.percentiles.Percentiles;

public class AggregationDemo {
public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
Percentiles percent=util.percentiles("salary");
for(Percentile p:percent) {
System.out.printf("percent [%f],value [%f]\n",p.getPercent(),p.getValue());
}
}
}

percent [1.000000],value [15000.000000]
percent [5.000000],value [15000.000000]
percent [25.000000],value [15500.000000]
percent [50.000000],value [17500.000000]
percent [75.000000],value [19500.000000]
percent [95.000000],value [20000.000000]
percent [99.000000],value [20000.000000]

（9）valueCount

public static void main(String[] args) {
AggregationUtil util=new AggregationUtil("my-index");
double count=util.valueCount("salary");
System.out.println("count="+count);

}

count=6.0