AIS.PL Commons - Bean

This library provides set of components and abstractions usable for bean proxying and validation.

Usage examples

Reporting validation errors to Spring Framework

Below you may find simple example of Person bean validation, reporting validation errors to Spring Framework.

import org.springframework.validation.Errors;
import pl.ais.commons.bean.domain.model.Person;
import pl.ais.commons.bean.validation.ValidationContext;
import pl.ais.commons.bean.validation.event.ValidationListener;
import pl.ais.commons.bean.validation.listener.SpringValidationListener;
...
import static pl.ais.commons.bean.validation.Constraints.notBlank;
import static pl.ais.commons.bean.validation.ValidationContext.validationOf;
...
    public void validate(final Person person, final Errors errors) {                
        final ValidationListener listener = new SpringValidationListener(errors);

        try (final ValidationContext<Person> validateThat = validationOf(person).observedBy(listener)) {

            final Person subject = validateThat.subject();

            validateThat.valueOf(subject.getNotes())
                        .satisfies(notBlank().withDescription("Notes should be defined!"));
            ...                        
        }
    }    

Note, that the above code will result in calling:

errors.rejectValue("notes", "notBlank", new Object[0], "Notes should be defined!");

each time if 'notes' property of Person bean is blank (empty or null). Path to validated property will be computed on-the-fly by the library classes, dropping necessity of hardcoding it into your code. Used message code depends on the constraint applied. There is also possibility of defining default message used, and the message parameters. For the details see Constraint API.