001    // Copyright 2006-2007 Daniel Gredler
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package net.sf.beanform.validator;
016    
017    import java.util.Locale;
018    
019    import org.apache.tapestry.form.IFormComponent;
020    import org.apache.tapestry.form.ValidationMessages;
021    import org.apache.tapestry.form.validator.BaseValidator;
022    import org.apache.tapestry.valid.ValidatorException;
023    
024    /**
025     * Base class for numeric validators.
026     *
027     * @author Daniel Gredler
028     */
029    public abstract class AbstractNumberValidator extends BaseValidator {
030    
031        public void validate( IFormComponent field, ValidationMessages messages, Object value )
032        throws ValidatorException {
033            if( value instanceof String ) {
034                try {
035                    String s = (String) value;
036                    this.parseNumber( s );
037                }
038                catch( NumberFormatException e ) {
039                    String msg = this.buildMessage( field, messages.getLocale() );
040                    throw new ValidatorException( msg );
041                }
042            }
043            else if( value != null ) {
044                String msg = this.buildMessage( field, messages.getLocale() );
045                throw new ValidatorException( msg );
046            }
047        }
048    
049        protected abstract void parseNumber( String s );
050        protected abstract String buildMessage( IFormComponent field, Locale locale );
051    
052    }