Struts example source code file (RequiredStringValidator.java)

This example Struts source code file (RequiredStringValidator.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, object, object, requiredstringvalidator, requiredstringvalidator, string, string, validationexception, validationexception

The Struts RequiredStringValidator.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 -->
 * RequiredStringValidator checks that a String field is non-null and has a length > 0.
 * (i.e. it isn't "").  The "trim" parameter determines whether it will {@link String#trim() trim}
 * the String before performing the length check.  If unspecified, the String will be trimmed.
 * <!-- END SNIPPET: javadoc -->
 * <p/>
 *
 * <!-- START SNIPPET: parameters -->
 * <ul>
 * 		<li>fieldName - The field name this validator is validating. Required if using Plain-Validator Syntax otherwise not required
 *      <li>trim - trim the field name value before validating (default is true)
 * </ul>
 * <!-- END SNIPPET: parameters -->
 * 
 * 
 * <pre>
 * <!-- START SNIPPET: examples -->
 *     <validators>
 *         <!-- Plain-Validator Syntax -->
 *         <validator type="requiredstring">
 *             <param name="fieldName">username</param>
 *             <param name="trim">true</param>
 *             <message>username is required</message>
 *         </validator>
 *         
 *         <!-- Field-Validator Syntax -->
 *         <field name="username">
 *         	  <field-validator type="requiredstring">
 *                 <param name="trim">true</param>
 *                 <message>username is required</message>
 *            </field-validator>
 *         </field>
 *     </validators>
 * <!-- END SNIPPET: examples -->
 * </pre>
 * 
 * @author rainerh
 * @version $Date: 2009-12-27 19:18:29 +0100 (Sun, 27 Dec 2009) $ $Id: RequiredStringValidator.java 894090 2009-12-27 18:18:29Z martinc $
 */
public class RequiredStringValidator extends FieldValidatorSupport {

    private boolean doTrim = true;


    public void setTrim(boolean trim) {
        doTrim = trim;
    }

    public boolean getTrim() {
        return doTrim;
    }

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

        if (!(value instanceof String)) {
            addFieldError(fieldName, object);
        } else {
            String s = (String) value;

            if (doTrim) {
                s = s.trim();
            }

            if (s.length() == 0) {
                addFieldError(fieldName, object);
            }
        }
    }
}