What is the difference between POJO and DAO

Question

May I know what is the difference between POJO (Plain old java object) and DAO (Data access object) in Java.

Where to use which one?

From the Jboss hibernate tutorial ( http://docs.jboss.org/hibernate/orm/4.2/manual/en-US/html/ch04.html#persistent-classes-pojo ), why POJO is used with database if we have DAO?

Thanks in advance

Answer 1

In Java parlance, a DAO is an organizing class that contains methods to access a database table. A POJO holds database records. A DAO will return POJOs from some of its methods.

Answer 2

Term is already easy to understand. It is Design pattern. if you agree it, you can use. Otherwise, you cannot.

As you mention

POJO is Plain old java object which take responsibility to keep the data, not business processing.

DAO is Data access object which take responsibility to process persistence/database processing.