I use jakarta's @AssertTrue on my object when I save it on the page to check if the phone number matches the mask:

@AssertTrue(message = "{validation.phone.incorrect}")
public boolean isCorrectPhone() {
    String phoneRegex = "^(\\+\\d{1,3}( )?)?((\\(\\d{1,3}\\))|\\d{1,3})[- .]?\\d{3,4}[- .]?\\d{4}$";
    return phone == null || phone.matches(phoneRegex);
}

The problem is that when the phone has incorrect format I get not the message that I expect, but a very detailed one with packages and classes used. And the message that I need is available only at the end of this message.

My expected message is: "Incorrect phone number".

What I get in exception looks like this:

Validation failed for argument [0] in public void com.my.user.UserController.editUser(com.my.entity.user.User): [Field error in object 'user' on field 'correctPhone': rejected value [false]; codes [AssertTrue.user.correctPhone,AssertTrue.correctPhone,AssertTrue]; arguments [.springframework.context.support.DefaultMessageSourceResolvable: codes [user.correctPhone,correctPhone]; arguments []; default message [correctPhone]]; default message [Incorrect phone number]]

.getCause() on the exception returns null, so there's no any nested exceptions with cleaner message. How do I get the message I want without parsing?

I use jakarta's @AssertTrue on my object when I save it on the page to check if the phone number matches the mask:

@AssertTrue(message = "{validation.phone.incorrect}")
public boolean isCorrectPhone() {
    String phoneRegex = "^(\\+\\d{1,3}( )?)?((\\(\\d{1,3}\\))|\\d{1,3})[- .]?\\d{3,4}[- .]?\\d{4}$";
    return phone == null || phone.matches(phoneRegex);
}

The problem is that when the phone has incorrect format I get not the message that I expect, but a very detailed one with packages and classes used. And the message that I need is available only at the end of this message.

My expected message is: "Incorrect phone number".

What I get in exception looks like this:

Validation failed for argument [0] in public void com.my.user.UserController.editUser(com.my.entity.user.User): [Field error in object 'user' on field 'correctPhone': rejected value [false]; codes [AssertTrue.user.correctPhone,AssertTrue.correctPhone,AssertTrue]; arguments [.springframework.context.support.DefaultMessageSourceResolvable: codes [user.correctPhone,correctPhone]; arguments []; default message [correctPhone]]; default message [Incorrect phone number]]

.getCause() on the exception returns null, so there's no any nested exceptions with cleaner message. How do I get the message I want without parsing?

• java
• spring
• validation

Share Improve this question Follow asked Mar 6 at 16:32 mykolamykola 1,80855 gold badges2727 silver badges3737 bronze badges

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2 Answers 2

Sorted by: Reset to default 0

Replace @AssertTrue with @Pattern, as this annotation is specifically designed for validating strings against a regular expression. In this case, the code will look like this:

@Pattern(regexp = "^(\\+\\d{1,3}( )?)?((\\(\\d{1,3}\\))|\\d{1,3})[- .]?\\d{3,4}[- .]?\\d{4}$", 
         message = "{validation.phone.incorrect}")
private String phone;

This solution will automatically bind the error message to the phone field instead of the isCorrectPhone() method, preventing the long message with technical details. At the same time, make sure that the messages.properties file contains the line validation.phone.incorrect=Incorrect phone number.

The problem was partly with our custom exception handlers one of which intercepted MethodArgumentNotValidException and wrapped it into Error (our custom, not java.lang) like this:

return new Error(ErrorCode.NOT_VALID, ex.getMessage());

So, this was the message I got. But as I said before I examined the exception there and saw that it doesn't have any root causes with clean message. I actually even tried to remove this handler at all to get a response like first snippet here but got even worse result:

{
    "timestamp": "2025-03-07T09:05:40.792+00:00",
    "status": 400,
    "error": "Bad Request",
    "path": "/api/users/edit"
}

No message at all! Just some generic error. I double checked: no other exception handlers intercepted this exception, so it was "clean" output.

But then I found out that actually MethodArgumentNotValidException has a method getFieldErrors() (I don't know why I didn't check for all available methods beforehand). This method contains a list of errors for all fields that are marked with either validation annotation. So, all I had to do is to loop through all field errors and get what I need, smth like:

return ex.getFieldErrors().stream()
        .map(error -> new FieldValidationError(error.getField(), error.getDefaultMessage(), error.getRejectedValue()))
        .toList();