AbstractPatternConstraintValidator.java

package org.jboss.capedwarf.validation.api;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.lang.annotation.Annotation;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * javax.validation pattern validator.
 *
 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
 */
public abstract class AbstractPatternConstraintValidator<T extends Annotation> implements ConstraintValidator<T, Object> {
    private Pattern pattern;

    /**
     * Create pattern from annotation.
     *
     * @param constraintAnnotation the constraint annotation
     * @return new pattern
     */
    protected abstract Pattern createPattern(T constraintAnnotation);

    public void initialize(T constraintAnnotation) {
        pattern = createPattern(constraintAnnotation);
    }

    /**
     * Check lenght.
     *
     * @param string the string to check
     * @return if null is returned we check the pattern, else return the boolean value
     */
    protected Boolean lengthCheck(String string) {
        return null;
    }

    public boolean isValid(Object value, ConstraintValidatorContext context) {
        if (value == null)
            return true;

        if (value instanceof String == false)
            return false;

        String string = (String) value;
        Boolean check = lengthCheck(string);
        if (check != null)
            return check;

        Matcher m = pattern.matcher(string);
        return m.matches();
    }
}