What is the purpose of the @EqualsAndHashCode annotation in Spring Boot?

In Spring Boot, the @EqualsAndHashCode annotation is used to automatically generate the equals() and hashCode() methods. The equals() method is for comparing if two objects are equal, while the hashCode() method is for generating the object’s hash code.

The @EqualsAndHashCode annotation can automatically generate the implementation of the equals() and hashCode() methods based on the fields defined in the class, eliminating the need to manually write these two methods. This annotation will generate comparison and hash code logic based on the specified fields.

Doing this can simplify the development process and reduce repetitive coding work. Additionally, since Spring Boot automatically handles the logic of equals() and hashCode() methods, it ensures the uniqueness of objects in collections. This is particularly useful when using collection classes like HashSet or HashMap, as it allows for accurate object identification and retrieval.

It is important to note that the @EqualsAndHashCode annotation by default will use all non-static and non-transient fields to generate logic for the equals() and hashCode() methods. If you only want to use certain fields for comparison, you can use the exclude or of attributes to exclude fields that should not be included in the comparison, or use the include attribute to specify only the fields that should be compared.

In general, the @EqualsAndHashCode annotation can streamline the development process, enhance code readability, and maintainability.