Java tutorial
/** * Copyright 2015 Q24 * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.kahu.hawaii.domain.validation; import io.kahu.hawaii.domain.ValidatableDomainProperty; import io.kahu.hawaii.domain.ValueHolder; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import org.apache.commons.lang.StringUtils; public class OptionalPropertyValidator implements ConstraintValidator<Optional, ValueHolder> { private String key; @Override public void initialize(Optional constraintAnnotation) { // Do nothing this.key = constraintAnnotation.key(); } @Override public boolean isValid(ValueHolder value, ConstraintValidatorContext context) { if (value != null && StringUtils.isNotBlank(key) && !value.isEmpty()) { if (value instanceof ValidatableDomainProperty) { if (!((ValidatableDomainProperty) value).validate()) { context.disableDefaultConstraintViolation(); context.buildConstraintViolationWithTemplate("INVALID").addConstraintViolation(); return false; } } } return true; } }