Question

I am validating the status of a record retrieved from the DB by defining an ENUM as below

public enum RecordStatusEnum {
    CREATED("CREATED"),
    INSERTED("INSERTED"),   
    FAILED("FAILED");

private String recordStatusValue;

    RecordStatusEnum (String status) {
        recordStatusValue= status;
    }

    public boolean isSuccess() {
        return (this.equals(CREATED) || this.equals(INSERTED));
    }

}

The method isSuccess() is being used to check the status of the retrieved record ( column status from employee)

if (!(employee.getStatus().isSuccess())) {
            // return error
        }

As per the new requirement, there are a set of conditions introduced say A,B and C; and for them there is a column in the Employee table ‘condition’.

So I need to retrieve the status as well as the condition and see if it belongs to a set which has the combination of both.

For eg : isSuccess() should check if in the following:

CREATED and A 
CREATED and B
INSERTED and C

This must be achieved such that it is easy for me to add a new combination say ‘INSERTED and B’ into the list easily.

What is the best approach for the above problem?

Note : in the actual business scenario there are a whole lot more statuses and checks (eg isFailed() canBeModified() etc) with many different combinations

And any method can be suggested even if it doesn’t use ENUMS. I mentioned ENUMS, because I dont want to deviate much from the existing implementation

Answer 1

There are many possibilities, but you could do like this (I removed the String status, which doesn’t add any value since it’s equal to the name of the enum):

public enum RecordStatusEnum {
    CREATED(Condition.A, Condition.B),
    INSERTED(Condition.C),   
    FAILED();

    private Set<Condition> successConditions;

    RecordStatusEnum(Condition... successConditions) {
        this.successConditions = EnumSet.copyOf(Arrays.asList(successConditions));
    }

    public boolean isSuccess(Condition c) {
        return successConditions.contains(c);
    }
}

EDIT:

Example with two sets of conditions:

public enum RecordStatusEnum {
    CREATED(EnumSet.of(Condition.A, Condition.B),
            EnumSet.of(Condition.C)),
    INSERTED(EnumSet.of(Condition.C),
             EnumSet.of(Condition.B),
    FAILED(EnumSet.noneOf(Condition.class),
           EnumSet.noneOf(Condition.class));

    private Set<Condition> successConditions;
    private Set<Condition> modificationConditions;

    RecordStatusEnum(Set<Condition> successConditions,
                     Set<Condition> modificationConditions) {
        this.successConditions = successConditions;
        this.modificationConditions = modificationConditions;
    }

    public boolean isSuccess(Condition c) {
        return successConditions.contains(c);
    }

    public boolean canBeModified(Condition c) {
        return modificationConditions.contains(c);
    }
}