重构多个if-else

Question

I have below code with lot of if else codition. Due to this if else code looking more complex and also sonar saying "Refactor this method to reduce its Cognitive Complexity from 17 to the 15 allowed."

Is there any other way so that I can reduce the complexcity.

    if (CONDITION1) {
        validatorVO.setErrorCode("ERROR_CODE_1");
    } else if (CONDITION2) {
        validatorVO.setErrorCode("ERROR_CODE_2");
    } else if (CONDITION3) {
        validatorVO.setErrorCode("ERROR_CODE_3");
    } else if (CONDITION4) {
        if (CONDITION5) {
            validatorVO.setErrorCode("ERROR_CODE_4");
        } else if (CONDITION6) {
            validatorVO.setErrorCode("ERROR_CODE_5");
        } else if (CONDITION7) {
            validatorVO.setErrorCode("ERROR_CODE_6");
        } else {
            validatorVO.setErrorCode("ERROR_CODE_7");
        }
    } else if (CONDITION8) {
        validatorVO.setErrorCode("ERROR_CODE_8");
    } else if (CONDITION9) {
        validatorVO.setErrorCode("ERROR_CODE_9");
    } else if (CONDITION10) {
        validatorVO.setErrorCode("ERROR_CODE_10");
    } else if (CONDITION11) {
        validatorVO.setErrorCode("ERROR_CODE_11");
    }
}

Note : Based on the condition error code will be different

Answer 1

With your amended question, one option would be to maintain a LinkedHashMap<Supplier<Boolean>, String> with the error codes (to preserve order). Note that the order matters (if you put CONDITION4 first, the combined conditions will never be checked).

Map<Supplier<Boolean>, String> conditions = new LinkedHashMap<> ();
conditions.put(() -> CONDITION1, "ERROR_CODE_1");
conditions.put(() -> CONDITION2, "ERROR_CODE_2");
conditions.put(() -> CONDITION3, "ERROR_CODE_3");
conditions.put(() -> CONDITION4 && CONDITION5, "ERROR_CODE_4");
conditions.put(() -> CONDITION4 && CONDITION6, "ERROR_CODE_5");
conditions.put(() -> CONDITION4 && CONDITION7, "ERROR_CODE_6");
conditions.put(() -> CONDITION4, "ERROR_CODE_7");
conditions.put(() -> CONDITION8, "ERROR_CODE_8");
conditions.put(() -> CONDITION9, "ERROR_CODE_9");
conditions.put(() -> CONDITION10, "ERROR_CODE_10");
conditions.put(() -> CONDITION11, "ERROR_CODE_11");

Then iterate:

for (Entry<Supplier<Boolean>, String> e : conditions.entrySet()) {
  if (e.getKey().get()) {
    validatorVO.setErrorCode(e.getValue());
    break;
  }
}

---

OLD ANSWER

Without knowing what the conditions are, it's hard to refactor the code too much.

You can write:

if (CONDITION1 || CONDITION2 || ... CONDITION11) validatorVO.setErrorCode("FAILED");

Of you may put the conditions in an array:

boolean[] conditions = {CONDITION1, CONDITION2, ...}
for (boolean b : conditions) {
  if (b) validatorVO.setErrorCode("FAILED");
}

Also note that you can exclude CONDITION5, CONDITION6 and CONDITION7 since they are ignored in your code (whether they are true or not makes not difference).

Answer 2

If the same result, then you can do something like:

if (CONDITION1 || CONDITION2 ||CONDITION3
     || CONDITION4
     || CONDITION8 || CONDITION9 ||CONDITION10 || CONDITION11) {
        validatorVO.setErrorCode("FAILED");
}

Actually, your CONDITION4 always evaluate

validatorVO.setErrorCode("FAILED");

regardless of CONDITION5 , CONDITION6 , CONDITION7 (thanks to Peter Lawrey for the hint)