Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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 com.vaadin.data.validator; import com.vaadin.data.ValidationResult; import com.vaadin.data.ValueContext; /** * Verifies that the length of a string is within the given range. * * @author Vaadin Ltd. * @since 8.0 */ @SuppressWarnings("serial") public class StringLengthValidator extends AbstractValidator<String> { private final RangeValidator<Integer> validator; /** * Creates a new StringLengthValidator with a given error message and * minimum and maximum length limits. * * @param errorMessage * the error message to return if validation fails * @param minLength * the minimum permissible length of the string or null for no * limit. * @param maxLength * the maximum permissible length of the string or null for no * limit. */ public StringLengthValidator(String errorMessage, Integer minLength, Integer maxLength) { super(errorMessage); validator = RangeValidator.of(errorMessage, minLength, maxLength); } @Override public ValidationResult apply(String value, ValueContext context) { if (value == null) { return toResult(value, true); } ValidationResult lengthCheck = validator.apply(value.length(), context); return toResult(value, !lengthCheck.isError()); } /** * Gets the maximum permissible length of the string. * * @return the maximum length of the string or null if there is no limit */ public Integer getMaxLength() { return validator.getMaxValue(); } /** * Gets the minimum permissible length of the string. * * @return the minimum length of the string or null if there is no limit */ public Integer getMinLength() { return validator.getMinValue(); } /** * Sets the maximum permissible length of the string. * * @param maxLength * the maximum length to accept or null for no limit */ public void setMaxLength(Integer maxLength) { validator.setMaxValue(maxLength); } /** * Sets the minimum permissible length. * * @param minLength * the minimum length to accept or null for no limit */ public void setMinLength(Integer minLength) { validator.setMaxValue(minLength); } @Override public String toString() { return String.format("%s[%d, %d]", getClass().getSimpleName(), getMinLength(), getMaxLength()); } }