Struts example source code file (StringLengthFieldValidator.java)

This example Struts source code file (StringLengthFieldValidator.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, string, string, stringlengthfieldvalidator, stringlengthfieldvalidator, validationexception, validationexception

The Struts StringLengthFieldValidator.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 -->
 * StringLengthFieldValidator checks that a String field is of a certain length.  If the "minLength"
 * parameter is specified, it will make sure that the String has at least that many characters.  If
 * the "maxLength" parameter is specified, it will make sure that the String has at most that many
 * characters.  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>maxLength - The max length of the field value. Default ignore.
 *    <li>minLength - The min length of the field value. Default ignore.
 *    <li>trim - Trim the field value before evaluating its min/max length. Default true
 * </ul>
 * <!-- END SNIPPET: parameters -->
 * 
 * 
 * <pre>
 * <!--START SNIPPET: example -->
 *      <validators>
 *           <!-- Plain Validator Syntax -->
 *           <validator type="stringlength">
 *                <param name="fieldName">myPurchaseCode</param>
 *                <param name="minLength">10</param>
 *                <param name="maxLength">10</param>
 *                <param name="trim">true</param>
 *                <message>Your purchase code needs to be 10 characters long</message>		
 *            </validator>
 * 
 *            <!-- Field Validator Syntax -->
 *            <field name="myPurchaseCode">
 *                <field-validator type="stringlength">
 *                     <param name="minLength">10</param>
 *                     <param name="maxLength">10</param>
 *                     <param name="trim">true</param>
 *                     <message>Your purchase code needs to be 10 characters long</message>
 *                </field-validator>
 *            </field>
 *      </validators>
 * <!-- END SNIPPET: example -->
 * </pre>
 * 
 *
 * @author Jason Carreira
 * @author Mark Woon
 * @author tmjee
 * @version $Date: 2009-12-27 19:18:29 +0100 (Sun, 27 Dec 2009) $ $Id: StringLengthFieldValidator.java 894090 2009-12-27 18:18:29Z martinc $
 */
public class StringLengthFieldValidator extends FieldValidatorSupport {

    private boolean doTrim = true;
    private int maxLength = -1;
    private int minLength = -1;


    public void setMaxLength(int maxLength) {
        this.maxLength = maxLength;
    }

    public int getMaxLength() {
        return maxLength;
    }

    public void setMinLength(int minLength) {
        this.minLength = minLength;
    }

    public int getMinLength() {
        return minLength;
    }

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

    public boolean getTrim() {
        return doTrim;
    }

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

        if (val == null || val.length() <= 0) {
            // use a required validator for these
            return;
        }
        if (doTrim) {
            val = val.trim();
            if (val.length() <= 0) { 
            	// use a required validator
            	return;
            }
        }

        if ((minLength > -1) && (val.length() < minLength)) {
            addFieldError(fieldName, object);
        } else if ((maxLength > -1) && (val.length() > maxLength)) {
            addFieldError(fieldName, object);
        }
    }
}