Annotations from javax validation constraints not working

Question

What configuration is needed to use annotations from javax validation constraints like  Size   NotNull  etc   Here s my code   import javax validation constraints NotNull  import javax validation constraints Size   public class Person          NotNull       private String id          Size max   3        private String name         private int age         public Person String id  String name  int age            this id   id          this name   name          this age   age              When I try to use it in another class  validation doesn t work  i e  the object is created without error    Person P   new Person null   Richard3   8229      Why doesn t this apply constraints for id and name  What else do I need to do

User · Answer

for method parameters you can use Objects requireNonNull   like this  test String str      Objects requireNonNull str     But this is only checked at runtime and throws an NPE if null   It is like a preconditions check   But that might be what you are looking for

User · Answer

I come here some years after  and I could fix it thanks to atrain s comment above  In my case  I was missing  Valid in the API that receives the Object  a POJO in my case  that was annotated with  Size  It solved the issue   I did not need to add any extra annotation  such as  Valid or  NotBlank to the variable annotated with  Size  just that constraint in the variable and what I  mentioned in the API     Pojo Class        Size min   MIN LENGTH  max   MAX LENGTH   private String exampleVar        API Class       public void exampleApiCall  RequestBody  Valid PojoObject pojoObject             Thanks and cheers

User · Answer

So  Valid at service interface would work for only that object  If you have any more validations within the hierarchy of ServiceRequest object then you might to have explicitly trigger validations  So this is how I have done it   public class ServiceRequestValidator          private static Validator validator          PostConstruct       public void init             validator   Validation buildDefaultValidatorFactory   getValidator                   public static  lt T gt  void validate T t           Set lt ConstraintViolation lt T gt  gt  errors   validator validate t           if CollectionUtils isNotEmpty errors              throw new ConstraintViolationException errors                         You need to have following annotations at the object level if you want to trigger validation for that object    Valid  NotNull

User · Answer

You can also simply use  NonNull with the lombok library instead  at least for the  NotNull scenario  More details  https   projectlombok org api lombok NonNull html

User · Answer

I came across this problem recently in a very similar situation  Met all requirements as the top-rated answer listed but still got the wrong result   So I looked at my dependencies and found I was missing some of them  I corrected it by adding the missing dependencies   I was using hibernate  the required dependencies were     Snapshot taken in class  Spring  amp  Hibernate for Beginners    Udemy

User · Answer

For JSR-303 bean validation to work in Spring  you need several things    MVC namespace configuration for annotations   lt mvc annotation-driven   gt  The JSR-303 spec JAR  validation-api-1 0 0 GA jar  looks like you already have that  An implementation of the spec  such as Hibernate Validation  which appears to be the most commonly used example  hibernate-validator-4 1 0 Final jar In the bean to be validated  validation annotations  either from the spec JAR or from the implementation JAR  which you have already done  In the handler you want to validate  annotate the object you want to validate with  Valid  and then include a BindingResult in the method signature to capture errors      Example    RequestMapping  handler do   public String myHandler  Valid  ModelAttribute  form   SomeFormBean myForm  BindingResult result  Model model        if result hasErrors               your error handling          else            your non-error handling

User · Answer

You would have to call a Validator on the Entity if you want to validate it  Then you will get a set of ConstraintViolationException  which basically show for which field s of your Entity there is a constraint violation and what exactly was it  Maybe you can also share some of the code you expect to validate your entity   An often used technique is to do validation in  PrePersist and rollback transaction if using multiple data modifications during transaction or do other actions when you get a validation exception    Your code should go like this    PrePersist public void prePersist SomeEntity someEntity       Validator validator   Validation buildDefaultValidatorFactory getValidator        Set lt ConstraintViolation lt SomeEntity gt  gt    validator validate someEntity         do stuff with them  like notify client what was the wrong field  log them  or  if empty  be happy

User · Answer

You should use Validator to check whether you class is valid   Person person         ValidatorFactory factory   Validation buildDefaultValidatorFactory    validator   factory getValidator    Set lt ConstraintViolation lt Person gt  gt  violations   validator validate person     Then  iterating violations set  you can find violations

User · Answer

In my case i removed these lines  1-import javax validation constraints NotNull   2-import javax validation constraints Size   3-       NotNull  4-     Size max   3

User · Answer

You need to add  Valid to each member variable  which was also an object that contained validation constraints

User · Answer

If you are using lombok then  you can use  NonNull annotation insted  or Just add the javax validation dependency in pom xml file

User · Answer

Great answer from atrain  but maybe better solution to catch exceptions is to utilize own HandlerExceptionResolver and catch      Override public ModelAndView resolveException      HttpServletRequest aReq       HttpServletResponse aRes      Object aHandler       Exception anExc                    if anExc instanceof MethodArgumentNotValidException     do your handle     error here     Then you re able to keep your handler as clean as possible  You don t need BindingResult  Model and SomeFormBean in myHandlerMethod anymore

User · Answer

After the Version 2 3 0 the  quot spring-boot-strarter-test quot   that included the NotNull NotBlank etc  is now  quot sprnig boot-strarter-validation quot  Just change it from     -test to    -validation and it should work  If not downgrading the version that you are using to 2 1 3 also will solve it

User · Answer

In my case  I was using spring boot version 2 3 0  When I changed my maven dependency to use 2 1 3 it worked    lt parent gt       lt groupId gt org springframework boot lt  groupId gt       lt artifactId gt spring-boot-starter-parent lt  artifactId gt       lt version gt 2 1 3 RELEASE lt  version gt       lt relativePath   gt   lt  -- lookup parent from repository -- gt   lt  parent gt   lt dependencies gt       lt dependency gt           lt groupId gt javax validation lt  groupId gt           lt artifactId gt validation-api lt  artifactId gt       lt  dependency gt   lt  dependencies gt

User · Answer

in my case i had a custom class-level constraint that was not being called    CustomValidation    not called public class MyClass        Lob      Column nullable   false      private String name      as soon as i added a field-level constraint to my class  either custom or standard  the class-level constraint started working    CustomValidation    now it works  super  public class MyClass        Lob      Column nullable   false       NotBlank    adding this made  CustomValidation start working     private String name      seems like buggy behavior to me but easy enough to work around i guess

[java] Annotations from javax.validation.constraints not working

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