1 /* 2 * Copyright (c) 2020, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 class Parent { 25 int get() {return 1;} 26 } 27 28 class Child extends Parent { 29 int get() {return 2;} 30 } 31 32 class MyShutdown extends Thread{ 33 public void run(){ 34 System.out.println("shut down hook invoked..."); 35 } 36 } 37 38 class LinkClassApp { 39 public static void main(String args[]) { 40 Runtime r=Runtime.getRuntime(); 41 r.addShutdownHook(new MyShutdown()); 42 43 if (args.length > 0 && args[0].equals("run")) { 44 System.out.println("test() = " + test()); 45 } else { 46 // Executed during dynamic dumping. 47 System.out.println("Test.class is initialized."); 48 System.out.println("Parent.class and Child.class are loaded when Test.class is verified,"); 49 System.out.println("but these two classes are not linked"); 50 } 51 52 if (args.length > 0 && args[0].equals("callExit")) { 53 System.exit(0); 54 } 55 } 56 57 static int test() { 58 // Verification of Test.test() would load Child and Parent, and create a verification constraint that 59 // Child must be a subtype of Parent. 60 // 61 // Child and Parent are not linked until Test.test() is actually executed. 62 Parent x = new Child(); 63 return x.get(); 64 } 65 }