1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package java.io; 19 20 /** 21 * A helper interface with constants used by the serialization implementation. 22 */ 23 public abstract interface ObjectStreamConstants { 24 25 /** 26 * The stream header's magic number. 27 */ 28 public static final short STREAM_MAGIC = (short) 0xaced; 29 30 /** 31 * The stream header's version number. 32 */ 33 public static final short STREAM_VERSION = 5; 34 35 // These are tags to indicate the stream contents 36 37 /** 38 * The minimum tag value. 39 */ 40 public static final byte TC_BASE = 0x70; 41 42 /** 43 * Tag to mark a {@code null} object reference. 44 */ 45 public static final byte TC_NULL = (byte) 0x70; 46 47 /** 48 * Tag to mark a reference to an object that has already been written to the 49 * stream. 50 */ 51 public static final byte TC_REFERENCE = (byte) 0x71; 52 53 /** 54 * Tag to mark a new class descriptor. 55 */ 56 public static final byte TC_CLASSDESC = (byte) 0x72; 57 58 /** 59 * Tag to mark a new object. 60 */ 61 public static final byte TC_OBJECT = (byte) 0x73; 62 63 /** 64 * Tag to mark a new string. 65 */ 66 public static final byte TC_STRING = (byte) 0x74; 67 68 /** 69 * Tag to mark a new array. 70 */ 71 public static final byte TC_ARRAY = (byte) 0x75; 72 73 /** 74 * Tag to mark a reference to a class. 75 */ 76 public static final byte TC_CLASS = (byte) 0x76; 77 78 /** 79 * Tag to mark a block of optional data. The byte following this tag 80 * indicates the size of the block. 81 */ 82 public static final byte TC_BLOCKDATA = (byte) 0x77; 83 84 /** 85 * Tag to mark the end of block data blocks for an object. 86 */ 87 public static final byte TC_ENDBLOCKDATA = (byte) 0x78; 88 89 /** 90 * Tag to mark a stream reset. 91 */ 92 public static final byte TC_RESET = (byte) 0x79; 93 94 /** 95 * Tag to mark a long block of data. The long following this tag 96 * indicates the size of the block. 97 */ 98 public static final byte TC_BLOCKDATALONG = (byte) 0x7A; 99 100 /** 101 * Tag to mark an exception. 102 */ 103 public static final byte TC_EXCEPTION = (byte) 0x7B; 104 105 /** 106 * Tag to mark a long string. 107 */ 108 public static final byte TC_LONGSTRING = (byte) 0x7C; 109 110 /** 111 * Tag to mark a new proxy class descriptor. 112 */ 113 public static final byte TC_PROXYCLASSDESC = (byte) 0x7D; 114 115 /** 116 * The maximum tag value. 117 */ 118 public static final byte TC_MAX = 0x7E; 119 120 /** 121 * Handle for the first object that gets serialized. 122 */ 123 public static final int baseWireHandle = 0x007e0000; 124 125 /** 126 * Stream protocol version 1. 127 */ 128 public static final int PROTOCOL_VERSION_1 = 1; 129 130 /** 131 * Stream protocol version 2. 132 */ 133 public static final int PROTOCOL_VERSION_2 = 2; 134 135 /** 136 * Permission constant to enable subclassing of ObjectInputStream and 137 * ObjectOutputStream. 138 */ 139 public static final SerializablePermission SUBCLASS_IMPLEMENTATION_PERMISSION = new SerializablePermission( 140 "enableSubclassImplementation"); 141 142 /** 143 * Permission constant to enable object substitution during serialization 144 * and deserialization. 145 */ 146 public static final SerializablePermission SUBSTITUTION_PERMISSION = new SerializablePermission( 147 "enableSubstitution"); 148 149 // Flags that indicate if the object was serializable, externalizable 150 // and had a writeObject method when dumped. 151 /** 152 * Bit mask for the {@code flag} field in ObjectStreamClass. Indicates 153 * that a serializable class has its own {@code writeObject} method. 154 */ 155 public static final byte SC_WRITE_METHOD = 0x01; // If SC_SERIALIZABLE 156 157 /** 158 * Bit mask for the {@code flag} field in ObjectStreamClass. Indicates 159 * that a class is serializable. 160 */ 161 public static final byte SC_SERIALIZABLE = 0x02; 162 163 /** 164 * Bit mask for the {@code flag} field in ObjectStreamClass. Indicates 165 * that a class is externalizable. 166 */ 167 public static final byte SC_EXTERNALIZABLE = 0x04; 168 169 /** 170 * Bit mask for the {@code flag} field in ObjectStreamClass. Indicates 171 * that an externalizable class is written in block data mode. 172 */ 173 public static final byte SC_BLOCK_DATA = 0x08; // If SC_EXTERNALIZABLE 174 175 /** 176 * Tag to mark a new enum. 177 */ 178 public static final byte TC_ENUM = 0x7E; 179 180 /** 181 * Bit mask for the {@code flag} field in ObjectStreamClass. Indicates 182 * that a class is an enum type. 183 */ 184 public static final byte SC_ENUM = 0x10; 185 } 186
