Bean Validation Annotations · Validation in Spring Boot | Spring Boot

Add the Starter

Never trust client input. Spring Boot uses Jakarta Bean Validation (implemented by Hibernate Validator). It is a separate starter:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

Common Constraints

Annotation (`jakarta.validation.constraints`)	Checks	Null allowed?
`@NotNull`	value is not null	no
`@NotBlank`	string is not null and not only spaces	no
`@NotEmpty`	string/collection not null and not empty	no
`@Size(min, max)`	length of string / size of collection	yes
`@Min` / `@Max`	whole number range	yes
`@Positive` / `@PositiveOrZero`	number > 0 / >= 0	yes
`@DecimalMin("0.01")` / `@Digits(integer, fraction)`	decimal limits and precision	yes
`@Email`	looks like an email address	yes
`@Pattern(regexp)`	matches a regular expression	yes
`@Past` / `@Future`	date before / after now	yes

Note: Most constraints treat null as valid. Combine them with @NotNull when the field is required: @NotNull @Positive BigDecimal price.

Annotating the ShopEase DTO

import jakarta.validation.constraints.*;
import java.math.BigDecimal;

public record CreateProductRequest(
        @NotBlank @Size(max = 120)
        String name,

        @Size(max = 2000)
        String description,

        @NotNull @DecimalMin("0.01") @Digits(integer = 8, fraction = 2)
        BigDecimal price,

        @PositiveOrZero
        int stock,

        @NotBlank(message = "category is required")
        String category) {}