or run

npx @tessl/cli init

Spring Boot Validation Package

Package: org.springframework.boot.validation

The validation package provides utilities and classes for Bean Validation (JSR-380) integration with Spring Boot, including message interpolation and method validation filtering.

Message Interpolation

MessageInterpolatorFactory

Factory for creating MessageInterpolator instances with automatic fallback support.

public class MessageInterpolatorFactory implements ObjectFactory<MessageInterpolator> {

    public MessageInterpolatorFactory();

    public MessageInterpolatorFactory(MessageSource messageSource);

    @Override
    public MessageInterpolator getObject() throws BeansException;
}

Features:

Automatically selects the best available MessageInterpolator from the classpath
Falls back to ParameterMessageInterpolator if the default provider is not available
Optionally wraps interpolator with MessageSource support for i18n

Example:

// Basic usage
MessageInterpolatorFactory factory = new MessageInterpolatorFactory();
MessageInterpolator interpolator = factory.getObject();

// With MessageSource for i18n support
@Bean
public MessageInterpolator messageInterpolator(MessageSource messageSource) {
    return new MessageInterpolatorFactory(messageSource).getObject();
}

MessageSourceMessageInterpolator

Resolves message parameters through MessageSource before final interpolation, enabling Spring i18n integration.

class MessageSourceMessageInterpolator implements MessageInterpolator {

    MessageSourceMessageInterpolator(
        MessageSource messageSource,
        MessageInterpolator messageInterpolator);

    @Override
    public String interpolate(String messageTemplate, Context context);

    @Override
    public String interpolate(String messageTemplate, Context context, Locale locale);
}

Features:

Resolves {messageKey} placeholders through MessageSource
Supports recursive parameter replacement
Detects circular references
Escaping with backslash: \{escaped\} → {escaped}

Example:

// messages.properties
validation.email.invalid=The email address is not valid
validation.size.min=Must be at least {min} characters

// Validation annotation
@Email(message = "{validation.email.invalid}")
private String email;

@Size(min = 5, message = "{validation.size.min}")
private String username;

Method Validation Filtering

MethodValidationExcludeFilter

Interface for excluding types from method validation based on custom criteria.

@FunctionalInterface
public interface MethodValidationExcludeFilter {

    boolean isExcluded(Class<?> type);

    static MethodValidationExcludeFilter byAnnotation(
        Class<? extends Annotation> annotationType);

    static MethodValidationExcludeFilter byAnnotation(
        Class<? extends Annotation> annotationType,
        SearchStrategy searchStrategy);
}

Factory Methods:

byAnnotation(Class) - Exclude types with annotation (inherited search)
byAnnotation(Class, SearchStrategy) - Exclude types with annotation (custom search strategy)

Example:

// Exclude all @RestController classes from method validation
MethodValidationExcludeFilter filter =
    MethodValidationExcludeFilter.byAnnotation(RestController.class);

// Custom implementation
MethodValidationExcludeFilter customFilter = type ->
    type.getPackageName().startsWith("com.example.legacy");

FilteredMethodValidationPostProcessor

Custom method validation post-processor that applies exclusion filters.

public class FilteredMethodValidationPostProcessor
        extends MethodValidationPostProcessor {

    public FilteredMethodValidationPostProcessor(
        Stream<? extends MethodValidationExcludeFilter> excludeFilters);

    public FilteredMethodValidationPostProcessor(
        Collection<? extends MethodValidationExcludeFilter> excludeFilters);

    @Override
    public void afterPropertiesSet();
}

Example:

@Configuration
public class ValidationConfig {

    @Bean
    public FilteredMethodValidationPostProcessor methodValidationPostProcessor() {
        // Exclude multiple types from method validation
        List<MethodValidationExcludeFilter> filters = List.of(
            MethodValidationExcludeFilter.byAnnotation(RestController.class),
            MethodValidationExcludeFilter.byAnnotation(Controller.class),
            type -> type.getName().contains("Internal")
        );

        return new FilteredMethodValidationPostProcessor(filters);
    }
}

Usage Examples

Setting Up Validation with MessageSource

@Configuration
public class ValidationConfiguration {

    @Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource =
            new ResourceBundleMessageSource();
        messageSource.setBasename("validation-messages");
        messageSource.setDefaultEncoding("UTF-8");
        return messageSource;
    }

    @Bean
    public LocalValidatorFactoryBean validator(MessageSource messageSource) {
        LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
        validator.setValidationMessageSource(messageSource);
        return validator;
    }
}

Creating Validation Messages

# validation-messages.properties
user.email.invalid=Please provide a valid email address
user.password.weak=Password must contain at least {min} characters
user.age.range=Age must be between {min} and {max}

# validation-messages_de.properties (German)
user.email.invalid=Bitte geben Sie eine gültige E-Mail-Adresse an
user.password.weak=Das Passwort muss mindestens {min} Zeichen enthalten
user.age.range=Das Alter muss zwischen {min} und {max} liegen

Using Custom Validation with Messages

public class User {

    @NotNull(message = "{user.email.invalid}")
    @Email(message = "{user.email.invalid}")
    private String email;

    @Size(min = 8, message = "{user.password.weak}")
    private String password;

    @Min(value = 18, message = "{user.age.range}")
    @Max(value = 120, message = "{user.age.range}")
    private int age;

    // Getters and setters
}

Excluding Controllers from Method Validation

@Configuration
public class MethodValidationConfig {

    @Bean
    public FilteredMethodValidationPostProcessor methodValidationPostProcessor() {
        // Don't validate methods in REST controllers
        // (request body validation is handled separately)
        return new FilteredMethodValidationPostProcessor(
            List.of(MethodValidationExcludeFilter.byAnnotation(RestController.class))
        );
    }
}

Combining Multiple Exclusion Filters

@Configuration
public class AdvancedValidationConfig {

    @Bean
    public FilteredMethodValidationPostProcessor methodValidationPostProcessor() {
        Stream<MethodValidationExcludeFilter> filters = Stream.of(
            // Exclude by annotation
            MethodValidationExcludeFilter.byAnnotation(RestController.class),
            MethodValidationExcludeFilter.byAnnotation(NoValidation.class),

            // Exclude by package
            type -> type.getPackageName().startsWith("com.example.legacy"),

            // Exclude by naming convention
            type -> type.getSimpleName().endsWith("Internal"),

            // Exclude interfaces
            Class::isInterface
        );

        return new FilteredMethodValidationPostProcessor(filters);
    }
}

// Custom marker annotation
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@interface NoValidation {
}

Service with Method Validation

@Service
@Validated
public class UserService {

    // Method parameters will be validated
    public void createUser(
        @Valid @NotNull User user,
        @NotBlank @Email String notificationEmail) {
        // Implementation
    }

    // Return value will be validated
    @NotNull
    public User findUser(@NotNull @Min(1) Long id) {
        // Implementation
        return user;
    }
}

Programmatic Validation with Custom Interpolator

@Component
public class ValidationHelper {

    private final Validator validator;

    public ValidationHelper(MessageSource messageSource) {
        MessageInterpolatorFactory factory =
            new MessageInterpolatorFactory(messageSource);
        MessageInterpolator interpolator = factory.getObject();

        Configuration<?> configuration = Validation
            .byDefaultProvider()
            .configure()
            .messageInterpolator(interpolator);

        ValidatorFactory validatorFactory = configuration.buildValidatorFactory();
        this.validator = validatorFactory.getValidator();
    }

    public <T> Set<ConstraintViolation<T>> validate(T object) {
        return validator.validate(object);
    }

    public void validateAndThrow(Object object) {
        Set<ConstraintViolation<Object>> violations = validator.validate(object);
        if (!violations.isEmpty()) {
            throw new ValidationException(
                violations.stream()
                    .map(ConstraintViolation::getMessage)
                    .collect(Collectors.joining(", "))
            );
        }
    }
}

Integration with Spring Boot Auto-Configuration

Spring Boot automatically configures validation when hibernate-validator is on the classpath:

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

// Gradle dependency
implementation 'org.springframework.boot:spring-boot-starter-validation'

Import Statements

import org.springframework.boot.validation.MessageInterpolatorFactory;
import org.springframework.boot.validation.beanvalidation.FilteredMethodValidationPostProcessor;
import org.springframework.boot.validation.beanvalidation.MethodValidationExcludeFilter;
import jakarta.validation.MessageInterpolator;
import jakarta.validation.Validator;
import jakarta.validation.ValidatorFactory;
import jakarta.validation.Validation;
import org.springframework.context.MessageSource;
import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
import org.springframework.validation.annotation.Validated;

Version

Tile

Files

validation.mddocs/

Spring Boot Validation Package

Message Interpolation

MessageInterpolatorFactory

MessageSourceMessageInterpolator

Method Validation Filtering

MethodValidationExcludeFilter

FilteredMethodValidationPostProcessor

Usage Examples

Setting Up Validation with MessageSource

Creating Validation Messages

Using Custom Validation with Messages

Excluding Controllers from Method Validation

Combining Multiple Exclusion Filters

Service with Method Validation

Programmatic Validation with Custom Interpolator

Integration with Spring Boot Auto-Configuration

Import Statements

Version

Tile

Files

validation.md.css-3qkkll{font-size:var(--chakra-font-sizes-sm);font-weight:var(--chakra-font-weights-normal);color:var(--chakra-colors-gray-300);}docs/

Spring Boot Validation Package

Message Interpolation

MessageInterpolatorFactory

MessageSourceMessageInterpolator

Method Validation Filtering

MethodValidationExcludeFilter

FilteredMethodValidationPostProcessor

Usage Examples

Setting Up Validation with MessageSource

Creating Validation Messages

Using Custom Validation with Messages

Excluding Controllers from Method Validation

Combining Multiple Exclusion Filters

Service with Method Validation

Programmatic Validation with Custom Interpolator

Integration with Spring Boot Auto-Configuration

Import Statements

validation.mddocs/