001// Copyright 2009 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 015package org.apache.tapestry5.internal.services; 016 017import org.apache.tapestry5.ioc.internal.util.CollectionFactory; 018import org.apache.tapestry5.services.InvalidationListener; 019 020import java.util.Map; 021 022public class StringInternerImpl implements StringInterner, InvalidationListener 023{ 024 private final Map<String, String> cache = CollectionFactory.newConcurrentMap(); 025 026 public void objectWasInvalidated() 027 { 028 cache.clear(); 029 } 030 031 public String intern(String string) 032 { 033 String result = cache.get(string); 034 035 // Not yet in the cache? Add it. 036 037 if (result == null) 038 { 039 cache.put(string, string); 040 result = string; 041 } 042 043 return result; 044 } 045 046 public String format(String format, Object... arguments) 047 { 048 return intern(String.format(format, arguments)); 049 } 050}