001 // Copyright May 31, 2006 The Apache Software Foundation 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 package org.apache.tapestry.data; 015 016 import org.apache.tapestry.services.DataSqueezer; 017 018 /** 019 * Handles null data assumedly? 020 * 021 * @author jcarman 022 */ 023 public class NullDataSqueezerFilter extends AbstractDataSqueezerFilter 024 { 025 private static final String NULL_STRING = "X"; 026 027 public String squeeze(Object data, DataSqueezer dataSqueezer) 028 { 029 if (data == null) 030 return NULL_STRING; 031 032 return dataSqueezer.squeeze(data); 033 } 034 035 public Object unsqueeze(String string, DataSqueezer dataSqueezer) 036 { 037 if (NULL_STRING.equals(string)) 038 return null; 039 040 return dataSqueezer.unsqueeze(string); 041 } 042 }