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1: /* URLStreamHandlerCache.java -- a cache for URLStreamHandlers 2: Copyright (C) 2006 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package gnu.java.net.loader; 40: 41: import java.net.URLStreamHandler; 42: import java.net.URLStreamHandlerFactory; 43: import java.util.HashMap; 44: 45: /** 46: */ 47: public class URLStreamHandlerCache 48: { 49: /** 50: * A cache to store mappings between handler factory and its 51: * private protocol handler cache (also a HashMap), so we can avoid 52: * creating handlers each time the same protocol comes. 53: */ 54: private HashMap factoryCache = new HashMap(5); 55: 56: public URLStreamHandlerCache() 57: { 58: } 59: 60: public synchronized void add(URLStreamHandlerFactory factory) 61: { 62: // Since we only support three protocols so far, 5 is enough 63: // for cache initial size. 64: if (factory != null && factoryCache.get(factory) == null) 65: factoryCache.put(factory, new HashMap(5)); 66: } 67: 68: public synchronized URLStreamHandler get(URLStreamHandlerFactory factory, 69: String protocol) 70: { 71: if (factory == null) 72: return null; 73: // Check if there're handler for the same protocol in cache. 74: HashMap cache = (HashMap) factoryCache.get(factory); 75: URLStreamHandler handler = (URLStreamHandler) cache.get(protocol); 76: if (handler == null) 77: { 78: // Add it to cache. 79: handler = factory.createURLStreamHandler(protocol); 80: cache.put(protocol, handler); 81: } 82: return handler; 83: } 84: }