[FIXED] Spring boot annotation validation set custom field name

Issue

In my spring boot rest application I'm doing validation via annotation and has the following class, how do I set a custom field name for the fields and use them in the error messages, the below example works, I can retrieve the value from the JSON payload and include them in the error message.

I need to set the name of the field to 'E-mail address' so I can put it in the error message.

The application also does not have any forms, input is received from json.

public class Contact {
    @Size(max = 20, message = ErrorMessages.INVALID_LENGTH)
    private String email;

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}


public class ErrorMessages {
    public static final String INVALID_LENGTH = "'${validatedValue}' must be between {min} and {max} characters long";
}

EDIT:

JSON input

{
        "email": "[email protected]"
}

expected output:

{
    "timestamp": "2022-06-13T00:32:28.861+00:00",
    "status": 400,
    "errors": [
        "E-mail address must be between 0 and 20 characters long"
    ]
}

I don't want to hard code the field name in the error message since I want to reuse it on other fields for checking their length. I want to do something similar to ${validatedValue} but with the name instead.

UPDATE:

Ok seems that setting a 'label' on a field to use in interpolation is not possible, I just created a class that contains the display names that I want to use and appended the error message to it:

public class FieldName {
    public static final String E_MAIL_ADDRESS = "E-mail address";
}


public class ErrorMessages {
    private static final String INVALID_LENGTH = " '${validatedValue}' must be between {min} and {max} characters long";
    public static final String E_MAIL_INVALID_LENGTH = FieldName.E_MAIL_ADDRESS + INVALID_LENGTH;
    
}

The payload class

public class Contact {
    @Size(max = 20, message = ErrorMessages.E_MAIL_INVALID_LENGTH)
    private String email;

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

Fixed output:

{
    "timestamp": "2022-06-13T03:27:03.207+00:00",
    "status": 400,
    "errors": [
        "E-mail address '[email protected]' must be between 0 and 20 characters long"
    ]
}

Solution

UPDATE: Ok seems that setting a 'label' on a field to use in interpolation is not possible, I just created a class that contains the display names that I want to use and appended the error message to it:

public class FieldName {
    public static final String E_MAIL_ADDRESS = "E-mail address";
}


public class ErrorMessages {
    private static final String INVALID_LENGTH = " '${validatedValue}' must be between {min} and {max} characters long";
    public static final String E_MAIL_INVALID_LENGTH = FieldName.E_MAIL_ADDRESS + INVALID_LENGTH;
    
}

The payload class

public class Contact {
    @Size(max = 20, message = ErrorMessages.E_MAIL_INVALID_LENGTH)
    private String email;

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

Fixed output:

{
    "timestamp": "2022-06-13T03:27:03.207+00:00",
    "status": 400,
    "errors": [
        "E-mail address '[email protected]' must be between 0 and 20 characters long"
    ]
}

Answered By - askwer
Answer Checked By - Gilberto Lyons (JavaFixing Admin)