Query engine cannot handle enums with constants that have overridden methods

[silvaran]

If I have an enum class such as the following:

public enum MyEnum {
  VAL0,
  VAL1 {
    @Override
    public boolean isTest() { return false; }
  },
  ;
  public boolean isTest() { return true; }
}

Hazelcast will fail if I query against an attribute of this enum on any cache entry that has a value of VAL1 (with the overridden method):

Unknown attribute type: MyEnum$2 for attribute: myAttribute: com.hazelcast.query.QueryException: Unknown attribute type: MyEnum$2 for attribute: myAttribute
com.hazelcast.query.impl.predicates.AbstractPredicate.convert(AbstractPredicate.java:148)
 	at com.hazelcast.query.impl.predicates.AbstractPredicate.convert(AbstractPredicate.java:132)
 	at com.hazelcast.query.impl.predicates.InPredicate.applyForSingleAttributeValue(InPredicate.java:100)

For an enum constant with an overridden method, the compiler creates an anonymous class that extends the enum's class and this anonymous class returns false for Class.isEnum().

com.hazelcast.query.impl.getters.ReflectionHelper.getAttributeType( Class klass ) makes use of isEnum. Maybe it should use Enum.isAssignableFrom( klass ).

[orcunc]

You need to use SqlPredicate. Here is an example
Assume that you have these objects

public enum MyState {
  STATE1 {
    @Override
    public boolean isTest() { return false; }
  },
  STATE2 {
    @Override
    public boolean isTest() { return true; }
  };

  public abstract boolean isTest();
}

public static class MyEmployee implements Serializable {
   MyState state;

   public MyEmployee(MyState state) {
     this.state = state;
   }

   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
     if (o == null || getClass() != o.getClass()) return false;
     MyEmployee that = (MyEmployee) o;
     return state == that.state;
   }

   @Override
   public int hashCode() {
     return Objects.hash(state);
   }
}

Then execute the SQL predicate

HazelcastInstance instance = ...;
IMap<Integer, MyEmployee> map = instance.getMap("map");

MyEmployee employee1 = new MyEmployee(State.STATE1);
map.put(1, employee1);


MyEmployee employee2 = new MyEmployee(State.STATE2);
map.put(2, employee2);


Collection<MyEmployee> values = map.values(Predicates.sql("state.test = true"));
assertThat(values).containsExactly(employee2);

You will see that you can query by Enum's value

[mwashburn]

Why did you close this? Can we just fix it rather than having to write our own custom predicates. Just merge the pull request.

[vbekiaris]

@mwashburn are you able to reproduce the issue with latest stable Hazelcast 5.3.2? If so, can you share your reproducer?