Generated immutable value classes for Java 7+
Kevin Bourrillion, Éamonn McManus
Google, Inc.
Value classes are extremely common in Java projects. These are classes for which you want to treat any two instances with suitably equal field values as interchangeable. That's right: we're talking about those classes where you wind up implementing equals, hashCode and toString in a bloated, repetitive, formulaic yet error-prone fashion.
Writing these methods the first time is not too bad, with the aid of a few helper methods and IDE templates. But once written they continue to burden reviewers, editors and future readers. Their wide expanses of boilerplate sharply decrease the signal-to-noise ratio of your code... and they love to harbor hard-to-spot bugs.
AutoValue provides an easier way to create immutable value classes, with a lot less code and less room for error, while not restricting your freedom to code almost any aspect of your class exactly the way you want it.
For more information, consult the detailed documentation