Java fields validation mechanism

Can you recommend any mechanism/technology/3rd party jar that does field validation (like field length validation, regexp validations and so on..)?

It's important that it would be highly configurable - meaning that I would be able to map between fields to a set of validations or something of that sort开发者_开发知识库.

Perhaps it should have also the ability to implement custom validators.

Any suggestion would be appreciated,

Thank you!

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javax.validation (JSF 303 - Bean Validation)

Hibernate validator is the reference implementation.

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take a look at Spring validator particularly the PropertyEditor part

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Apache has a package for this http://commons.apache.org/validator/ Struts has this built-in as well