Inspectopedia Help

'equals()' and 'hashCode()' not paired

Reports classes that override the equals() method but do not override the hashCode() method or vice versa, which can potentially lead to problems when the class is added to a Collection or a HashMap.

The quick-fix generates the default implementation for an absent method.

Example:

class StringHolder { String s; @Override public int hashCode() { return s != null ? s.hashCode() : 0; } }

After the quick-fix is applied:

class StringHolder { String s; @Override public int hashCode() { return s != null ? s.hashCode() : 0; } @Override public boolean equals(Object o) { if (this == o) return true; if (!(o instanceof StringHolder)) return false; StringHolder holder = (StringHolder)o; if (s != null ? !s.equals(holder.s) : holder.s != null) return false; return true; } }

Inspection Details

By default bundled with:

IntelliJ IDEA 2024.1, Qodana for JVM 2024.1,

Can be installed with plugin:

Java, 241.16690

Last modified: 29 April 2024