Struts example source code file (RequiredFieldValidator.java)

This example Struts source code file (RequiredFieldValidator.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

fieldvalidatorsupport, fieldvalidatorsupport, object, object, requiredfieldvalidator, string, string, validationexception, validationexception

The Struts RequiredFieldValidator.java source code

/*
 * Copyright 2002-2006,2009 The Apache Software Foundation.
 * 
 * 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.opensymphony.xwork2.validator.validators;

import com.opensymphony.xwork2.validator.ValidationException;


/**
 * <!-- START SNIPPET: javadoc -->
 * RequiredFieldValidator checks if the specified field is not null.
 * <!-- END SNIPPET: javadoc -->
 * <p/>
 * 
 * 
 * <!-- START SNIPPET: parameters -->
 * <ul>
 * 		<li>fieldName - field name if plain-validator syntax is used, not needed if field-validator syntax is used
 * </ul>
 * <!-- END SNIPPET: parameters -->
 * 
 * 
 * <pre>
 * <!-- START SNIPPET: example -->
 * 	   <validators>
 * 
 *         <!-- Plain Validator Syntax -->
 *         <validator type="required">
 *             <param name="fieldName">username</param>
 *             <message>username must not be null</message>
 *         </validator>
 * 
 * 
 *         <!-- Field Validator Syntax -->
 *         <field name="username">
 *             <field-validator type="required">
 *             	   <message>username must not be null</message>
 *             </field-validator>
 *         </field>
 * 
 *     </validators>
 * <!-- END SNIPPET: example -->
 * </pre>
 * 
 * 
 *
 * @author rainerh
 * @version $Revision: 894090 $
 */
public class RequiredFieldValidator extends FieldValidatorSupport {

    public void validate(Object object) throws ValidationException {
        String fieldName = getFieldName();
        Object value = this.getFieldValue(fieldName, object);

        if (value == null) {
            addFieldError(fieldName, object);
        }
    }
}