001 /* 002 Copyright (C) 2001 Laurent Martelli <laurent@aopsys.com> 003 004 This program is free software; you can redistribute it and/or modify 005 it under the terms of the GNU Lesser General Public License as 006 published by the Free Software Foundation; either version 2 of the 007 License, or (at your option) any later version. 008 009 This program is distributed in the hope that it will be useful, 010 but WITHOUT ANY WARRANTY; without even the implied warranty of 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 012 GNU Lesser General Public License for more details. 013 014 You should have received a copy of the GNU Lesser General Public License 015 along with this program; if not, write to the Free Software 016 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ 017 018 package org.objectweb.jac.util; 019 020 import java.util.HashMap; 021 import java.util.Map; 022 import org.apache.log4j.Logger; 023 024 025 /** 026 * Use only put(Object,Object) and get(Object). 027 */ 028 public class LinkedMap extends HashMap { 029 static Logger logger = Logger.getLogger("util.map"); 030 031 Map next; 032 public LinkedMap() { 033 } 034 public LinkedMap(Map next) { 035 this.next = next; 036 } 037 public Object get(Object key) { 038 if (super.containsKey(key)) { 039 return super.get(key); 040 } else { 041 Object result = null; 042 if (next!=null) { 043 result = next.get(key); 044 logger.debug(key+" not found, trying next -> "+result); 045 put(key,result); 046 } 047 return result; 048 } 049 } 050 public boolean containsKey(Object key) { 051 if (super.containsKey(key)) { 052 return true; 053 } else { 054 return next!=null && next.containsKey(key); 055 } 056 } 057 }