如何将聚合与 HazelcastJsonValue 一起使用？

Question

如何使用 HazelcastJsonValue 的聚合？

我正在尝试使用：

Long count = map1.aggregate(Aggregators.count(), e -> "name='John'".equals(e.getValue()));        
Long count = map1.aggregate(Aggregators.count("name='John'"));

但我在这两种情况下都得到 0，而实际结果应该是 4。

这是一个示例代码：

    HazelcastInstance hazelCast = Hazelcast.newHazelcastInstance();
    IMap<String, HazelcastJsonValue> map1 = hazelCast.getMap("map1");

    map1.put("1", new HazelcastJsonValue("{"name":"John", "age":31, "city":"New York"}"));
    map1.put("2",  new HazelcastJsonValue("{"name":"John", "age":31, "city":"New York"}"));
    map1.put("3", new HazelcastJsonValue("{"name":"John", "age":31, "city":"New York"}"));
    map1.put("4",  new HazelcastJsonValue("{"name":"John", "age":31, "city":"New York"}"));
    
    Long count = map1.aggregate(Aggregators.count(), e -> "name='John'".equals(e.getValue()));
    Long count = map1.aggregate(Aggregators.count("name='John'"));

    System.out.println(count);

Answer 1

谓词在我看来 well-formed 不一样——在第一个中，您要使用 'equals' 与一部分比较整个 JSON 文档（多个字段）的文档，所以它永远不会匹配。

对我有用的是：

Config c = new Config();
HazelcastInstance hazelCast = Hazelcast.newHazelcastInstance(c);
IMap<String, HazelcastJsonValue> map1 = hazelCast.getMap("map1");

HazelcastJsonValue jsv = new HazelcastJsonValue("{\"name\":\"John\", \"age\":31, \"city\":\"New York\"}");
map1.put("A", jsv);
map1.put("B", jsv);

Predicate p = Predicates.equal("name", "John");
long count = map1.aggregate(Aggregators.count(), p);
System.out.println("Count: " + count);
hazelCast.shutdown();

如何将聚合与 HazelcastJsonValue 一起使用？

How to use aggregations with HazelcastJsonValue?

java

hazelcast

hazelcast-aggregate