java操作elasticsearch实现聚合查询

1、max 最大值

//max 求最大值
    @Test
    public void test30() throws UnknownHostException{
        //1、指定es集群  cluster.name 是固定的key值，my-application是ES集群的名称
        Settings settings = Settings.builder().put("cluster.name", "my-application").build();
        //2.创建访问ES服务器的客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.94"), 9300));
        //aggMax为最大值的别名 ，age是要求最大值的列
        AggregationBuilder builder = AggregationBuilders.max("aggMax").field("age");
        SearchResponse response = client.prepareSearch("lib3").addAggregation(builder).get();
        Max max = response.getAggregations().get("aggMax");
        //打印最大值
        System.out.println(max.getValue());
    }

2、min：最小值

//min 求最小值
        @Test
        public void test31() throws UnknownHostException{
            //1、指定es集群  cluster.name 是固定的key值，my-application是ES集群的名称
            Settings settings = Settings.builder().put("cluster.name", "my-application").build();
            //2.创建访问ES服务器的客户端
            TransportClient client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.94"), 9300));
            //aggMin为最小值的别名 ，age是要求最小值的列
            AggregationBuilder builder = AggregationBuilders.min("aggMin").field("age");
            SearchResponse response = client.prepareSearch("lib3").addAggregation(builder).get();
            Min min = response.getAggregations().get("aggMin");
            //打印最小值
            System.out.println(min.getValue());
        }

3、avg：平均值

//avg 求平均值
        @Test
        public void test32() throws UnknownHostException{
            //1、指定es集群  cluster.name 是固定的key值，my-application是ES集群的名称
            Settings settings = Settings.builder().put("cluster.name", "my-application").build();
            //2.创建访问ES服务器的客户端
            TransportClient client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.94"), 9300));
            //aggavg为平均值的别名 ，age是要求最大值的列
            AggregationBuilder builder = AggregationBuilders.avg("aggavg").field("age");
            SearchResponse response = client.prepareSearch("lib3").addAggregation(builder).get();
            Avg avg = response.getAggregations().get("aggavg");
            //打印平均值
            System.out.println(avg.getValue());
        }

4、sum：求和

//sum 求和
        @Test
        public void test33() throws UnknownHostException{
            //1、指定es集群  cluster.name 是固定的key值，my-application是ES集群的名称
            Settings settings = Settings.builder().put("cluster.name", "my-application").build();
            //2.创建访问ES服务器的客户端
            TransportClient client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.94"), 9300));
            //aggSum为总和的别名 ，age是要求总和的列
            AggregationBuilder builder = AggregationBuilders.max("aggSum").field("age");
            SearchResponse response = client.prepareSearch("lib3").addAggregation(builder).get();
            Sum sum = response.getAggregations().get("aggSum");
            //打印总和
            System.out.println(sum.getValue());
        }

5、cardinality:求基数

　　说明：基数就是互不相同的个数，具体看代码及注释

//cardinality基数（互不相同的个数）
        @Test
        public void test34() throws UnknownHostException{
            //1、指定es集群  cluster.name 是固定的key值，my-application是ES集群的名称
            Settings settings = Settings.builder().put("cluster.name", "my-application").build();
            //2.创建访问ES服务器的客户端
            TransportClient client = new PreBuiltTransportClient(settings)
                    .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.1.94"), 9300));
            //Cardinality基数查询： 查询age字段中互不相同的个数
            AggregationBuilder builder = AggregationBuilders.cardinality("aggCardinality").field("age");
            SearchResponse response = client.prepareSearch("lib3").addAggregation(builder).get();
            Cardinality cardinality = response.getAggregations().get("aggCardinality");
            //打印基数
            System.out.println(cardinality.getValue());
        }

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