Java – used to check Lombok builders that are not null but not empty

I have a variable class and I don't want it to be null or empty Is there any way to use the Lombok builder to set properties? I can use @ nonnull, but I cannot verify that it is empty Obviously, another option is to write my own builder to perform all these checks For example:

class Person {
    @NonNull
    private String firstName;
    @NonNull
    private String lastName;

    public static class PersonBuilder() {
        // .
        // .
        // .
        public Person build() {
            //do checks for empty etc and return object
        }
    }
}

Solution

Maxim kirilov's answer is incomplete It does not check for spaces / empty strings

I've encountered the same problem before, and I realized that in addition to using @ nonnull and @ builder from Lombok, I also overloaded the constructor with a private access modifier, where you can perform validation Something like this:

private Person(final String firstName,final String lastName) {
    if(StringUtils.isBlank(firstName)) {
        throw new IllegalArgumentException("First name can't be blank/empty/null"); 
    }
    if(StringUtils.isBlank(lastName)) {
        throw new IllegalArgumentException("Last name can't be blank/empty/null"); 
    }
    this.firstName = firstName;
    this.lastName = lastName;
}

In addition, it makes more sense to throw illegalargumentexception (rather than NPE) when string has null value, null value or null value