Validate positive integers

Question

I want to allow only positive integers for number fields including zero. How can I define this validation using JSR 303 ?
I tried

1. @Min(value=0 message = "msg1") - But it allows float values like 1.2.

2. @Digits(fraction = 0, integer = 10, message ="msg2") - It accepts negative values.

3. @Min(value=0, message = "msg1" )
@Digits(fraction = 0, integer = 10, message ="msg2") - It works fine but sometimes both the messages i.e. msg1 and msg2 are displayed.

Any suggestions?

Thanks!

Answer 1

Just use the annotation @Min in your bean:

@Min(value = 0L, message = "The value must be positive")
private Double value;

Answer 2

Looks like you are looking for natural numbers, I think you can use the regex pattern to get the desired output. Something like

@Pattern(regexp = "[\\s]*[0-9]*[1-9]+",message="msg")

Answer 3

You can use @Positive that works for the int and its wrappers too (ie Integer). This also will work for the BigInteger as well.

Answer 4

If you use hibernate-validator then you may create a custom constraint which combines @Min and @Digits from the 3rd option by using @ConstraintComposition(AND). When you add @ReportAsSingleViolation, only a custom message will be shown.

Answer 5

Its better to use range annotation like below for positive numbers

@Range(min = 0l, message = "Please select positive numbers Only")

For negative numbers

@Range(min = -9223372036854775808l, max = 0l, message = "Please select Negative numbers Only")

Answer 6

Another kind of solution and in my personal opinion cleaner and easier to read.

@Positive
@Digits(integer = 5, fraction = 0)

Answer 7

This is an example code from the answer https://stackoverflow.com/a/41675990/258544 above

@Documented
@Min(value=0, message = "add a min msg" )
@Digits(fraction = 0, integer = 10, message ="add a digit msg")
@Target({ElementType.METHOD, ElementType.FIELD, ElementType.ANNOTATION_TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = {})
@ReportAsSingleViolation
public @interface NumberFormatValidator {

    String message() default "invalid number";

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

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

}

It use Constraint composition http://docs.jboss.org/hibernate/validator/4.3/reference/en-US/html_single/#validator-customconstraints-compound and @ReportAsSingleViolation to avoid display both messages

Answer 8

Change the data time of your field from int to Integer and a message.properties file to set the message

Example: assuming your fieldName is myNumericField and belongs to a class called Test

1. Change the datatype:

   • change private int myNumericField; to private Integer myNumericField;

   • Update getters and setters to use/return Integer

2. Create custom message.properties file. This may appear to be more work but it's a more elegant and scalable solution rather than having the messages hardcoded in your annotations

   • Create a message.properties file under resources directory

   • Edit messages.properties and add the following line

   typeMismatch.Test.myNumericField=Please use integers only

   Remember to change Test and myNumericField for your class and field name

   • Edit your Application Context xml file and add the following tags before the <\beans> tag

   <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basenames" value="resources/messages" /> </bean>

Answer 9

Using the following combination solved the issue for me:

  @NotNull
  @Range(min = 1)
  @JsonProperty("end_range")
  private Integer endRange;

Make sure to use Integer class instead of int for @NotNull to work.