SimpleStringValidator.java

/*
 * Copyright 2022 Global Crop Diversity Trust
 *
 * 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 org.gringlobal.custom.validation.javax;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

/**
 * @author Matija Obreza
 */
public class SimpleStringValidator implements ConstraintValidator<SimpleString, String> {

    /**
     * Initializes the validator.
     */
    @Override
    public void initialize(SimpleString constraintAnnotation) {
    }

    /**
     * Implements the validation logic.
     * @return {@code false} if {@code value} contains line break characters, tab, double white space or is not trimmed
     */
    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        if (value == null) {
            return true;
        }
        return value.trim().equals(value) && value.indexOf('\n') == -1 && value.indexOf('\r') == -1 && value.indexOf("  ") == -1 && !value.matches("\\s\\s");
    }

}