Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.apache.wicket.validation; import org.apache.wicket.markup.html.form.FormComponent; /** * Marker interface for validators that will accept a <code>null</code> value. Without implementing * this interface Wicket will never pass <code>null</code> values to * {@link IValidator#validate(IValidatable)}. * <p> * Keep in mind that the {@link FormComponent} must have set the required property to * <code>false</code>, otherwise Wicket will not permit the validator to process the * <code>null</code> value. * * @author Matej Knopp * @param <T> * type of validatable * @since 1.2.6 * @see IValidator * @see FormComponent#setRequired(boolean) */ public interface INullAcceptingValidator<T> extends IValidator<T> { }