Ideally speaking, a POJO is a Java object not bound by any restriction other than those forced by the Java Language Specification; i.e. a POJO should not have to 1). Extend prespecified classes, as in [crayon-69b029899c3a0706281205/] 2). Implement prespecified interfaces, as in [crayon-69b029899c3af500214615/] 3). Contain prespecified annotations, as in [crayon-69b029899c3b4442270646/] sumber: wiki 185