1 /* 2 * Copyright (c) 2005, 2007, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package java.io; 26 27 import java.util.*; 28 import java.io.File; 29 30 /** 31 * This class holds a set of filenames to be deleted on VM exit through a shutdown hook. 32 * A set is used both to prevent double-insertion of the same file as well as offer 33 * quick removal. 34 */ 35 36 class DeleteOnExitHook { 37 private static LinkedHashSet<String> files = new LinkedHashSet<String>(); 38 static { 39 // DeleteOnExitHook must be the last shutdown hook to be invoked. 40 // Application shutdown hooks may add the first file to the 41 // delete on exit list and cause the DeleteOnExitHook to be 42 // registered during shutdown in progress. So set the 43 // registerShutdownInProgress parameter to true. 44 sun.misc.SharedSecrets.getJavaLangAccess() 45 .registerShutdownHook(2 /* Shutdown hook invocation order */, 46 true /* register even if shutdown in progress */, 47 new Runnable() { 48 public void run() { 49 runHooks(); 50 } 51 } 52 ); 53 } 54 55 private DeleteOnExitHook() {} 56 57 static synchronized void add(String file) { 58 if(files == null) { 59 // DeleteOnExitHook is running. Too late to add a file 60 throw new IllegalStateException("Shutdown in progress"); 61 } 62 63 files.add(file); 64 } 65 66 static void runHooks() { 67 LinkedHashSet<String> theFiles; 68 69 synchronized (DeleteOnExitHook.class) { 70 theFiles = files; 71 files = null; 72 } 73 74 ArrayList<String> toBeDeleted = new ArrayList<String>(theFiles); 75 76 // reverse the list to maintain previous jdk deletion order. 77 // Last in first deleted. 78 Collections.reverse(toBeDeleted); 79 for (String filename : toBeDeleted) { 80 (new File(filename)).delete(); 81 } 82 } 83 }