CODEWITHSUNDEEP
spring-bootvalidation
diaop
diaop

Reputation: 57

Allow numeric values in Spring Validation

I dont want to allow 0 but at the same time any decimal values above it should be passed through. When I keep @Min(value=0..) 0 is being bypassed but I want to prevent that but allow 0.1.

How do I allow values like 0.1, 0.2?

    @NotNull(message = "distance should not be empty")
    @Min(value = 1, message = "distance value should be above 0.")
    private Double distance;

Upvotes: 0

Views: 1417

Answers (1)

DEWA Kazuyuki - 出羽和之
DEWA Kazuyuki - 出羽和之

Reputation: 2643

You can create custom constraints:

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE_USE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Documented;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;

@Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE, TYPE_USE })
@Retention(RUNTIME)
@Constraint(validatedBy = GreaterThanValidator.class)
@Documented
@Repeatable(GreaterThan.List.class)
public @interface GreaterThan {

    String message() default "${validatedValue} must be greater than {value}";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    double value();

    @Target({ FIELD, METHOD, PARAMETER, ANNOTATION_TYPE })
    @Retention(RUNTIME)
    @Documented
    @interface List {
        GreaterThan[] value();
    }
}

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class GreaterThanValidator implements ConstraintValidator<GreaterThan, Double> {

    private double range;

    @Override
    public void initialize(final GreaterThan constraintAnnotation) {
        this.range = constraintAnnotation.value();
    }

    @Override
    public boolean isValid(final Double value, final ConstraintValidatorContext context) {
        if (value == null) {
            return true;
        }

        return value.doubleValue() > this.range;
    }

}

Usage:

        @NotNull(message = "distance should not be empty")
        @GreaterThan(value = 0, message = "distance value should be above 0.")
        private Double distance;

Upvotes: 1

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