| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.services.io.ArrayUtil |
| 4 | |
| 5 | Copyright 1997, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.services.io; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | import java.io.ObjectOutput; |
| 25 | import java.io.ObjectInput; |
| 26 | import java.io.IOException; |
| 27 | import java.lang.reflect.Array; |
| 28 | |
| 29 | /** |
| 30 | Utility class for constructing and reading and writing arrays from/to |
| 31 | formatId streams. |
| 32 | |
| 33 | @version 0.1 |
| 34 | @author Rick Hillegas |
| 35 | */ |
| 36 | public abstract class ArrayUtil |
| 37 | { |
| 38 | /////////////////////////////////////////////////////////////////// |
| 39 | // |
| 40 | // Methods for Arrays of OBJECTS. Cannot be used for an |
| 41 | // array of primitives, see below for something for primitives |
| 42 | // |
| 43 | /////////////////////////////////////////////////////////////////// |
| 44 | /** |
| 45 | Write the length of an array of objects to an output stream. |
| 46 | |
| 47 | The length |
| 48 | |
| 49 | @param out ObjectOutput stream |
| 50 | @param a array of objects whose length should be written. |
| 51 | |
| 52 | @exception java.io.IOException The write caused an IOException. |
| 53 | */ |
| 54 | public static void writeArrayLength(ObjectOutput out, Object[] a) |
| 55 | throws IOException |
| 56 | { |
| 57 | out.writeInt(a.length); |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | Write an array of objects to an output stream. |
| 62 | |
| 63 | @param out Object output stream to write to. |
| 64 | @param a array of objects to write. |
| 65 | |
| 66 | @exception java.io.IOException The write caused an IOException. |
| 67 | */ |
| 68 | public static void writeArrayItems(ObjectOutput out, Object[] a) |
| 69 | throws IOException |
| 70 | { |
| 71 | if (a == null) |
| 72 | return; |
| 73 | |
| 74 | for(int ix = 0; ix < a.length; ix++) |
| 75 | { out.writeObject(a[ix]); } |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | Write an array of objects and length to an output stream. |
| 80 | Does equivalent of writeArrayLength() followed by writeArrayItems() |
| 81 | |
| 82 | @param out Object output stream to write to. |
| 83 | @param a array of objects to write. |
| 84 | |
| 85 | @exception java.io.IOException The write caused an IOException. |
| 86 | */ |
| 87 | public static void writeArray(ObjectOutput out, Object[] a) |
| 88 | throws IOException |
| 89 | { |
| 90 | if (a == null) |
| 91 | { |
| 92 | out.writeInt(0); |
| 93 | return; |
| 94 | } |
| 95 | |
| 96 | out.writeInt(a.length); |
| 97 | for(int ix = 0; ix < a.length; ix++) |
| 98 | { out.writeObject(a[ix]); } |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | Read an array of objects out of a stream. |
| 103 | |
| 104 | @param in Input stream |
| 105 | @param a array to read into |
| 106 | |
| 107 | @exception java.io.IOException The write caused an IOException. |
| 108 | @exception java.lang.ClassNotFoundException The Class for an Object we are reading does not exist |
| 109 | */ |
| 110 | public static void readArrayItems(ObjectInput in, Object[] a) |
| 111 | throws IOException, ClassNotFoundException |
| 112 | { |
| 113 | for (int ix=0; ix<a.length; ix++) |
| 114 | { |
| 115 | a[ix]=in.readObject(); |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | Read the length of an array of objects in an object stream. |
| 121 | |
| 122 | @param in Input stream. |
| 123 | |
| 124 | @return length of the array of objects |
| 125 | |
| 126 | @exception java.io.IOException The write caused an IOException. |
| 127 | */ |
| 128 | public static int readArrayLength(ObjectInput in) |
| 129 | throws IOException |
| 130 | { |
| 131 | return in.readInt(); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | Reads an array of objects from the stream. |
| 136 | |
| 137 | @param in Input stream |
| 138 | |
| 139 | @exception java.io.IOException The write caused an IOException. |
| 140 | @exception java.lang.ClassNotFoundException The Class for an Object we are reading does not exist |
| 141 | */ |
| 142 | public static Object[] readObjectArray(ObjectInput in) |
| 143 | throws IOException, ClassNotFoundException |
| 144 | { |
| 145 | int size = in.readInt(); |
| 146 | if ( size == 0 ) { return null; } |
| 147 | |
| 148 | Object[] result = new Object[ size ]; |
| 149 | |
| 150 | readArrayItems( in, result ); |
| 151 | |
| 152 | return result; |
| 153 | } |
| 154 | |
| 155 | /////////////////////////////////////////////////////////////////// |
| 156 | // |
| 157 | // Methods for Arrays of INTs |
| 158 | // |
| 159 | /////////////////////////////////////////////////////////////////// |
| 160 | |
| 161 | /** |
| 162 | Write an array of integers to an ObjectOutput. This writes the array |
| 163 | in a format readIntArray understands. |
| 164 | |
| 165 | @param out the ObjectOutput. |
| 166 | @param a the array. |
| 167 | @exception java.io.IOException The write caused an IOException. |
| 168 | */ |
| 169 | public static void writeIntArray(ObjectOutput out, int[] a) throws IOException { |
| 170 | if (a == null) |
| 171 | out.writeInt(0); |
| 172 | else { |
| 173 | out.writeInt(a.length); |
| 174 | for (int i=0; i<a.length; i++) |
| 175 | out.writeInt(a[i]); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | Read an array of integers from an ObjectInput. This allocates the |
| 181 | array. |
| 182 | |
| 183 | @param in the ObjectInput. |
| 184 | @return the array of integers. |
| 185 | |
| 186 | @exception java.io.IOException The write caused an IOException. |
| 187 | */ |
| 188 | public static int[] readIntArray(ObjectInput in) throws IOException { |
| 189 | int length = in.readInt(); |
| 190 | if (length == 0) |
| 191 | return null; |
| 192 | int[] a = new int[length]; |
| 193 | for (int i=0; i<length; i++) |
| 194 | a[i] = in.readInt(); |
| 195 | return a; |
| 196 | } |
| 197 | |
| 198 | public static void writeInts( ObjectOutput out, int[][] val ) |
| 199 | throws IOException |
| 200 | { |
| 201 | if (val == null) |
| 202 | { |
| 203 | out.writeBoolean(false); |
| 204 | } |
| 205 | else |
| 206 | { |
| 207 | out.writeBoolean(true); |
| 208 | |
| 209 | int count = val.length; |
| 210 | out.writeInt( count ); |
| 211 | |
| 212 | for (int i = 0; i < count; i++) |
| 213 | { |
| 214 | ArrayUtil.writeIntArray( out, val[i] ); |
| 215 | } |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | public static int[][] readInts( ObjectInput in ) |
| 220 | throws IOException, ClassNotFoundException |
| 221 | { |
| 222 | int[][] retVal = null; |
| 223 | |
| 224 | if ( in.readBoolean() ) |
| 225 | { |
| 226 | int count = in.readInt(); |
| 227 | |
| 228 | retVal = new int[ count ][]; |
| 229 | |
| 230 | for (int i = 0; i < count; i++) |
| 231 | { |
| 232 | retVal[ i ] = ArrayUtil.readIntArray( in ); |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | return retVal; |
| 237 | } |
| 238 | |
| 239 | /////////////////////////////////////////////////////////////////// |
| 240 | // |
| 241 | // Methods for Arrays of LONGs |
| 242 | // |
| 243 | /////////////////////////////////////////////////////////////////// |
| 244 | |
| 245 | /** |
| 246 | Write an array of longs to an ObjectOutput. This writes the array |
| 247 | in a format readLongArray understands. |
| 248 | |
| 249 | @param out the ObjectOutput. |
| 250 | @param a the array. |
| 251 | @exception java.io.IOException The write caused an IOException. |
| 252 | */ |
| 253 | public static void writeLongArray(ObjectOutput out, long[] a) throws IOException { |
| 254 | if (a == null) |
| 255 | out.writeInt(0); |
| 256 | else { |
| 257 | out.writeInt(a.length); |
| 258 | for (int i=0; i<a.length; i++) |
| 259 | out.writeLong(a[i]); |
| 260 | } |
| 261 | } |
| 262 | |
| 263 | /** |
| 264 | Read an array of integers from an ObjectInput. This allocates the |
| 265 | array. |
| 266 | |
| 267 | @param in the ObjectInput. |
| 268 | @return the array of integers. |
| 269 | |
| 270 | @exception java.io.IOException The write caused an IOException. |
| 271 | */ |
| 272 | public static long[] readLongArray(ObjectInput in) throws IOException { |
| 273 | int length = in.readInt(); |
| 274 | long[] a = new long[length]; |
| 275 | for (int i=0; i<length; i++) |
| 276 | a[i] = in.readLong(); |
| 277 | return a; |
| 278 | } |
| 279 | |
| 280 | /** |
| 281 | Read an array of strings from an ObjectInput. This allocates the |
| 282 | array. |
| 283 | |
| 284 | @param in the ObjectInput. |
| 285 | @return the array of integers. |
| 286 | |
| 287 | @exception java.io.IOException The write caused an IOException. |
| 288 | */ |
| 289 | public static String[] readStringArray(ObjectInput in) |
| 290 | throws IOException, ClassNotFoundException |
| 291 | { |
| 292 | Object[] objArray = readObjectArray(in); |
| 293 | int size = 0; |
| 294 | |
| 295 | if (objArray == null) |
| 296 | return null; |
| 297 | |
| 298 | String[] stringArray = new String[size = objArray.length]; |
| 299 | |
| 300 | for (int i = 0; i < size; i++) |
| 301 | { |
| 302 | stringArray[i] = (String)objArray[i]; |
| 303 | } |
| 304 | |
| 305 | return stringArray; |
| 306 | } |
| 307 | |
| 308 | /////////////////////////////////////////////////////////////////// |
| 309 | // |
| 310 | // Methods for Arrays of BOOLEANS |
| 311 | // |
| 312 | /////////////////////////////////////////////////////////////////// |
| 313 | |
| 314 | /** |
| 315 | Write an array of booleans to an ObjectOutput. This writes the array |
| 316 | in a format readBooleanArray understands. |
| 317 | |
| 318 | @param out the ObjectOutput. |
| 319 | @param a the array. |
| 320 | @exception java.io.IOException The write caused an IOException. |
| 321 | */ |
| 322 | public static void writeBooleanArray(ObjectOutput out, boolean[] a) throws IOException { |
| 323 | if (a == null) |
| 324 | out.writeInt(0); |
| 325 | else { |
| 326 | out.writeInt(a.length); |
| 327 | for (int i=0; i<a.length; i++) |
| 328 | out.writeBoolean(a[i]); |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | /** |
| 333 | Read an array of integers from an ObjectInput. This allocates the |
| 334 | array. |
| 335 | |
| 336 | @param in the ObjectInput. |
| 337 | @return the array of integers. |
| 338 | |
| 339 | @exception java.io.IOException The write caused an IOException. |
| 340 | */ |
| 341 | public static boolean[] readBooleanArray(ObjectInput in) throws IOException { |
| 342 | int length = in.readInt(); |
| 343 | boolean[] a = new boolean[length]; |
| 344 | for (int i=0; i<length; i++) |
| 345 | a[i] = in.readBoolean(); |
| 346 | return a; |
| 347 | } |
| 348 | } |