1/* 2 * Copyright (c) 1998, 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/* @test 25 * @bug 4140729 26 * @summary Verify that writeReplace & readResolve are called by serialization. 27 * readResolve is used to maintain the invariant that the enums 28 * of TypeSafeEnum are singletons. 29 */ 30import java.io.*; 31 32public class TypeSafeEnum implements Serializable, ObjectInputValidation { 33 private static int numWriteObject = 0; 34 private static int numReadObject = 0; 35 36 37 private String value; 38 private TypeSafeEnum(String value) { 39 this.value = value; 40 } 41 42 public static final TypeSafeEnum FIRST = new TypeSafeEnum("First"); 43 public static final TypeSafeEnum SECOND = new TypeSafeEnum("Second"); 44 public static final TypeSafeEnum THIRD = new TypeSafeEnum("Third"); 45 static int numReadResolve = 0; 46 static int numWriteReplace = 0; 47 static boolean verbose = false; 48 49 50 private Object writeReplace() throws IOException { 51 numWriteReplace++; 52 if (verbose) { 53 System.out.println("TypeSafeEnum.writeReplace() " + 54 this.toString()); 55 } 56 return this; 57 } 58 59 private Object readResolve() throws IOException { 60 numReadResolve++; 61 if (verbose) { 62 System.out.println("readResolve called on " + this.toString()); 63 } 64 if (value.equals(FIRST.value)) { 65 return FIRST; 66 } else if (value.equals(SECOND.value)) { 67 return SECOND; 68 } else if (value.equals(THIRD.value)) { 69 return THIRD; 70 } else { 71 //unknown type safe enum 72 return this; 73 } 74 } 75 76 private void readObject(ObjectInputStream in) 77 throws IOException, ClassNotFoundException 78 { 79 numReadObject++; 80 in.defaultReadObject(); 81 if (verbose) { 82 System.out.println("TypeSafeEnum.readObject() " + this.toString()); 83 } 84 if (value == null) { 85 in.registerValidation(this, 0); 86 } 87 } 88 89 public void validateObject() throws InvalidObjectException { 90 // only top level case has null for value, validate. 91 if (numWriteObject != 4) { 92 throw new Error("Expected 4 calls to writeObject, only " + 93 numWriteObject + " made"); 94 } 95 if (numReadObject != 4) { 96 throw new Error("Expected 4 calls to readObject, only " + 97 numReadObject + " made"); 98 } 99 if (numWriteReplace != 4) { 100 throw new Error("Expected 4 calls to writeReplace, only " + 101 numWriteReplace + " made"); 102 } 103 if (numReadResolve != 4) { 104 throw new Error("Expected 4 calls to readResolve, only " + 105 numReadResolve + " made"); 106 } 107 } 108 109 private void writeObject(ObjectOutputStream out) throws IOException 110 { 111 numWriteObject++; 112 out.defaultWriteObject(); 113 if (verbose) { 114 System.out.println("TypeSafeEnum.writeObject() " + 115 this.toString()); 116 } 117 } 118 119 public String toString() { 120 return super.toString() + " value=" + value; 121 } 122 123 public static void main(String args[]) 124 throws IOException, ClassNotFoundException 125 { 126 if (args.length > 0 && args[0].equals("-verbose")) 127 verbose = true; 128 129 TypeSafeEnum[] writeArray = new TypeSafeEnum[7]; 130 writeArray[0] = FIRST; 131 writeArray[1] = SECOND; 132 writeArray[2] = THIRD; 133 writeArray[3] = FIRST; 134 writeArray[4] = SECOND; 135 writeArray[5] = THIRD; 136 writeArray[6] = new TypeSafeEnum("Third"); 137 138 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 139 ObjectOutputStream os = new ObjectOutputStream(baos); 140 os.writeObject(writeArray); 141 os.close(); 142 143 TypeSafeEnum[] readArray; 144 ObjectInputStream in = 145 new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray())); 146 readArray = (TypeSafeEnum[])in.readObject(); 147 in.close(); 148 149 for (int i= 0; i < writeArray.length - 1 ; i++) { 150 if (writeArray[i] != readArray[i]) { 151 throw new Error("Serializa/deserialize did not preserve " + 152 "singleton for " + 153 readArray[i].toString() + 154 " and " + writeArray[i].toString()); 155 } 156 } 157 } 158}; 159