Record With Array Component Missing Overrides
ID |
java.equals_method_overridden_records_containing |
Severity |
high |
Remediation Complexity |
medium |
Remediation Risk |
low |
Remediation Effort |
medium |
Resource |
Code Smell |
Language |
Java |
Tags |
best-practice, reliability |
Description
Reports a record with an array-typed (or varargs) component that does not override equals, hashCode and toString.
Rationale
A record’s generated equals, hashCode and toString compare and print components by value — except array components, which they treat by reference. Two records holding arrays with the same elements compare unequal, hashCode() varies between otherwise-identical instances, and toString() prints something like [I@1a2b3c instead of the array’s content.
// Bad -- scores is compared and printed by reference
record Measurement(String subject, int[] scores) {
}Remediation
Override equals, hashCode and toString to delegate to java.util.Arrays for every array component.
// Good -- array content drives equality, hashing and printing
record Measurement(String subject, int[] scores) {
@Override
public boolean equals(Object o) {
if (!(o instanceof Measurement)) {
return false;
}
Measurement other = (Measurement) o;
return subject.equals(other.subject) && Arrays.equals(scores, other.scores);
}
@Override
public int hashCode() {
return 31 * subject.hashCode() + Arrays.hashCode(scores);
}
@Override
public String toString() {
return subject + "=" + Arrays.toString(scores);
}
}