1 /* 2 * Copyright (c) 2017, 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 /* 25 * @test 26 * @bug 8186961 27 * @run main/othervm StaticFieldsOnInterface C 28 * @run main/othervm StaticFieldsOnInterface D 29 * @run main/othervm StaticFieldsOnInterface Y 30 */ 31 32 public class StaticFieldsOnInterface { 33 /* 34 A 35 / \ 36 B C 37 \ / 38 D 39 40 Interface A has a public field 41 Ensure B, C, D only report exactly one public field 42 43 A 44 / 45 X A 46 |/ 47 Y 48 49 Ensure class Y, extending class X, reports exactly one public field 50 */ 51 52 public interface A { 53 public static final int CONSTANT = 42; 54 } 55 56 public interface B extends A { 57 } 58 59 public interface C extends A { 60 } 61 62 public interface D extends B, C { 63 } 64 65 static class X implements A {} 66 static class Y extends X implements A {} 67 main(String[] args)68 public static void main(String[] args) throws Exception { 69 char first = 'C'; 70 if (args.length > 0) { 71 first = args[0].charAt(0); 72 } 73 74 assertOneField(A.class); 75 // D first 76 if (first == 'D') { 77 assertOneField(D.class); 78 assertOneField(C.class); 79 } 80 // C first 81 else if (first == 'C') { 82 assertOneField(C.class); 83 assertOneField(D.class); 84 } 85 else { 86 assertOneField(Y.class); 87 } 88 } 89 assertOneField(Class<?> c)90 static void assertOneField(Class<?> c) { 91 int nfs = c.getFields().length; 92 if (nfs != 1) { 93 throw new AssertionError(String.format( 94 "Class %s does not have exactly one field: %d", c.getName(), nfs)); 95 } 96 } 97 } 98