I'm surprised I haven't seen anybody mention the "public final fields" approach yet. I use this myself for immutable objects and I quite like it. Granted, you s

I'm surprised I haven't seen anybody mention the "public final fields" approach yet. I use this myself for immutable objects and I quite like it. Granted, you still need to implement equals and hashcode, but these can be generated easily and verified with tools like EqualsVerifier [2]. [1] public class MyImmutable { public final String field1; public final int field2; public MyImmutable(String field1, int field2) { // assign } // equals, hashcode, toString } [2] https://github.com/jqno/equalsverifier https://github.com/jqno/equalsverifier