72 lines
1.8 KiB
Plaintext
72 lines
1.8 KiB
Plaintext
== Why is this an issue?
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In records, the default behavior of the ``++equals()++`` method is to check the equality by field values. This works well for primitive fields or fields, whose type overrides ``++equals()++``, but this behavior doesn't work as expected for array fields.
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By default, array fields are compared by their reference, and overriding ``++equals()++`` is highly appreciated to achieve the deep equality check. The same strategy applies to ``++hashCode()++`` and ``++toString()++`` methods.
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This rule reports an issue if a record class has an array field and is not overriding ``++equals()++``, ``++hashCode()++`` or ``++toString()++`` methods.
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=== Noncompliant code example
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[source,java]
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----
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record Person(String[] names, int age) {} // Noncompliant
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----
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=== Compliant solution
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[source,java]
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----
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record Person(String[] names, int age) {
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@Override
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public boolean equals(Object o) {
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if (this == o) return true;
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if (o == null || getClass() != o.getClass()) return false;
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Person person = (Person) o;
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return age == person.age && Arrays.equals(names, person.names);
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}
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@Override
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public int hashCode() {
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int result = Objects.hash(age);
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result = 31 * result + Arrays.hashCode(names);
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return result;
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}
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@Override
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public String toString() {
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return "Person{" +
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"names=" + Arrays.toString(names) +
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", age=" + age +
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'}';
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}
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}
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----
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== Resources
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* https://docs.oracle.com/javase/specs/jls/se16/html/jls-8.html#jls-8.10[Records specification]
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Override [equals|hashCode|toString] to consider array's content in the method
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=== Highlighting
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record declaration
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endif::env-github,rspecator-view[]
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