Bean Validation constraints may be applied to persistent entity classes, embeddable classes, and mapped superclasses.By default, the Persistence provider will automatically perform validation on entities with persistent fields or properties annotated with Bean Validation constraints immediately after the lifecycle events. ~ characters are legal in the local part of an e-mail address but in the above regular expression those characters are filtered out. It begins with at least one or more word characters including the underscore, equivalent to [A-Za-z0-9_]. A lot of websites now require registration, meaning that users need to be assigned a username and password.Input validation should be applied on both syntactical and semantic level.
Input validation should happen as early as possible in the data flow, preferably as soon as the data is received from the external party.
SSN, date, currency symbol) while semantic validation should enforce correctness of their values in the specific business context (e.g.
start date is before end date, price is within expected range).
Custom constraint developers must also provide a validator class for the constraint.
Bean Validation constraints are applied to the persistent fields or properties of persistent classes.
Bean Validation constraints are annotations applied to the fields or properties of Java programming language classes.