java-validation-annotations

Java Bean Validation is applied to VO classes by adding standard JSR-380 annotations like @NotNull, @NotBlank, @Pattern, @Min, @Max, and @Size directly to your fields, ensuring proper data integrity and consistent validation rules across your domain model.

Java field validation uses @NotNull to reject null values and @NotBlank to reject null, empty, or whitespace-only strings, ensuring text fields contain meaningful data before processing.

Regex validation in Java uses the @Pattern annotation alongside predefined DataPattern constants, centralizing common regular expressions to enforce consistent formatting rules across multiple fields and domain models efficiently.

Grouped validations can be applied to REST API request payloads in Java by assigning validation groups to JSR-380 annotations, allowing you to enforce specific constraint sets like NotNull or Size during different processing phases.

Java Bean Validation supports custom Chinese error messages by configuring the message attribute within JSR-380 annotations, allowing you to specify localized validation feedback directly on fields like @Pattern or @NotBlank.

JSR-380 annotations for entity validation are limited to declarative constraints like @Min and @Size, meaning complex cross-field logic or conditional validation rules require additional manual programmatic validation.