（25）ElasticSearch java项目中聚合查询terms、filter、filters、range、missing

　　1、按年龄分组,查询每组的个数

@Test
    public void testTerms() throws IOException, InterruptedException, ExecutionException {
        //指定集群
        Settings settings = Settings.builder().put("cluster.name","my-application").build(); 
        //创建客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.43.151"),9300));
        //创建查询对象,按年龄分组,查询每组的个数
        AggregationBuilder agg = AggregationBuilders.terms("terms").field("age");
        //执行查询
        SearchResponse sr = client.prepareSearch("lib3")
                                  .addAggregation(agg)
                                  .execute()
                                  .actionGet();
        //获取结果
        Terms terms = sr.getAggregations().get("terms");
        //遍历
        for(Terms.Bucket entry:terms.getBuckets()) {
            System.out.println(entry.getKey()+"----------"+entry.getDocCount());
        }
        client.close();
   }

　　2、过滤查询age字段是20的文档

@Test
    public void testFilter() throws IOException, InterruptedException, ExecutionException {
        //指定集群
        Settings settings = Settings.builder().put("cluster.name","my-application").build(); 
        //创建客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.43.151"),9300));
        //指定查询条件，age字段是20的
        QueryBuilder query = QueryBuilders.termQuery("age", 29);
        //过滤查询条件，过滤出满足查询条件的文档
        AggregationBuilder agg = AggregationBuilders.filter("filter", query);
        //执行查询
        SearchResponse sr = client.prepareSearch("lib3")
                                  .addAggregation(agg)
                                  .execute()
                                  .actionGet();
        //获取结果
        Filter filter = sr.getAggregations().get("filter");
        //输出个数
        System.out.println(filter.getDocCount());
        client.close();
   }

　　3、过滤查询interests字段包含changge、hejiu的文档

@Test
    public void testFilters() throws IOException, InterruptedException, ExecutionException {
        //指定集群
        Settings settings = Settings.builder().put("cluster.name","my-application").build(); 
        //创建客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.43.151"),9300));
        //指定查询条件，interests字段包含changge的
        QueryBuilder query = QueryBuilders.termQuery("interests", "changge");
        //指定查询条件，interests字段包含hejiu的
        QueryBuilder query2 = QueryBuilders.termQuery("interests", "hejiu");
        //过滤查询条件，过滤出满足query或者query2的文档
        AggregationBuilder agg = AggregationBuilders.filters("filters",
                                                            new FiltersAggregator.KeyedFilter("条件1",query),
                                                            new FiltersAggregator.KeyedFilter("条件2",query2));
        //执行查询
        SearchResponse sr = client.prepareSearch("lib3")
                                  .addAggregation(agg)
                                  .execute()
                                  .actionGet();
        //获取结果
        Filters filters = sr.getAggregations().get("filters");
        //遍历,指定了两个filter，所以输出两条数据，key分别是条件1、条件2
        for(Filters.Bucket entry:filters.getBuckets()) {
            System.out.println(entry.getKey()+"----------"+entry.getDocCount());
        }
        client.close();
   }

　　4、分别统计年龄小于50的，25到50之间的，大于25的文档个数

@Test
    public void testRange() throws IOException, InterruptedException, ExecutionException {
        //指定集群
        Settings settings = Settings.builder().put("cluster.name","my-application").build(); 
        //创建客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.43.151"),9300));
        //统计3组数据年龄小于50的，25到50之间的，大于25的
        AggregationBuilder agg = AggregationBuilders.range("range")
                                                    .field("age")
                                                    .addUnboundedTo(50)//( ,to)
                                                    .addRange(25,50)//[from,to)
                                                    .addUnboundedFrom(25);//[from, )
        //执行查询
        SearchResponse sr = client.prepareSearch("lib3")
                                  .addAggregation(agg)
                                  .execute()
                                  .actionGet();
        //获取结果
        Range r = sr.getAggregations().get("range");
        //遍历,输出3个key，*-50.0；25.0-50.0；25.0-*
        for(Range.Bucket entry:r.getBuckets()) {
            System.out.println(entry.getKey()+"----------"+entry.getDocCount());
        }
        client.close();
   }

　　5、统计缺失age字段的文档个数

@Test
    public void testMissing() throws IOException, InterruptedException, ExecutionException {
        //指定集群
        Settings settings = Settings.builder().put("cluster.name","my-application").build(); 
        //创建客户端
        TransportClient client = new PreBuiltTransportClient(settings)
                                .addTransportAddress(new TransportAddress(InetAddress.getByName("192.168.43.151"),9300));
        //统计缺失字段age的文档
        AggregationBuilder agg = AggregationBuilders.missing("missing").field("age");
        //执行查询
        SearchResponse sr = client.prepareSearch("lib3")
                                  .addAggregation(agg)
                                  .execute()
                                  .actionGet();
        //获取结果
        Aggregation aggregation = sr.getAggregations().get("missing");
        //输出结果
        System.out.println(aggregation.toString());
        client.close();
   }