JPA 2.0 : what is javax.validation.* package?

问题

What is the javax.validation package in Java EE? How to use this with JPA?

I want to validate my JPA Entity with the @NotNull annotation. My JPA implementation is Hibernate.

Here's my Entity:

public class Employee implements Serializable , EmployeeDetail {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private int id;

    private String name;

    private long salary;
    ...

回答1:

Using the Bean Validation Api you can quite easy ensure standard validation (not null, patterns, email) on your entities (or beans in common).

Check out Oracles tutorials for Bean Validation Api: http://docs.oracle.com/javaee/6/tutorial/doc/gircz.html

Also Hibernate should be no problem with this, as it is the reference implementation: http://www.hibernate.org/subprojects/validator.html

For a good introduction check Hibernates tutorial on this topic: http://docs.jboss.org/hibernate/validator/4.0.1/reference/en/html_single/

Some other tutorials (Google for JPA 2 + Bean Validation)

http://www.jboss.org/jdf/examples/ticket-monster/tutorial/DataPersistence/
http://musingsofaprogrammingaddict.blogspot.de/2010/01/jpa-2-and-bean-validation-in-action.html

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