1.3 KiB
1.3 KiB
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| POJO |
POJO
POJO stands for "Plain Old Java Object". This is different from Plain Old Javascript Objects. A Plain Old Java Object refers to the Object Oriented Programming (OOP) paradigm that is used in the Java programming language. The OOP model treats data as 'objects'. Each 'object' is an instance of a 'Class', which represents the archetype or template from which all objects inherit their properties and attributes.
A POJO is therefore simply a Java Object. However, it must also satisfy the following additional criteria:
- it must not extend prespecified Java Classes;
public class Foo extends javax.servlet.http.HttpServlet {
...// body ...
}
- it must not implement prespecified Interfaces;
public class Bar implements javax.ejb.EntityBean {
... // body
}
- it must not contain prespecified Annotations.
@javax.persistence.Entity public class Baz {
... // body ...
}
Therefore a Java Object qualifies as a POJO only when it is free from the above modifications. It therefore follows that a POJO is not 'bound by any restrictions' other those prescribed by the formal Java language specification.