1 /*
2 * Copyright (c) 1996, 2013, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.reflect;
27
28 import jdk.internal.HotSpotIntrinsicCandidate;
29
30 /**
31 * The {@code Array} class provides static methods to dynamically create and
32 * access Java arrays.
33 *
34 * <p>{@code Array} permits widening conversions to occur during a get or set
35 * operation, but throws an {@code IllegalArgumentException} if a narrowing
36 * conversion would occur.
37 *
38 * @author Nakul Saraiya
39 * @since 1.1
40 */
41 public final
42 class Array {
43
44 /**
45 * Constructor. Class Array is not instantiable.
46 */
47 private Array() {}
48
49 /**
50 * Creates a new array with the specified component type and
51 * length.
52 * Invoking this method is equivalent to creating an array
53 * as follows:
54 * <blockquote>
55 * <pre>
56 * int[] x = {length};
57 * Array.newInstance(componentType, x);
58 * </pre>
59 * </blockquote>
60 *
61 * <p>The number of dimensions of the new array must not
62 * exceed 255.
63 *
64 * @param componentType the {@code Class} object representing the
65 * component type of the new array
66 * @param length the length of the new array
67 * @return the new array
68 * @exception NullPointerException if the specified
69 * {@code componentType} parameter is null
70 * @exception IllegalArgumentException if componentType is {@link
71 * Void#TYPE} or if the number of dimensions of the requested array
72 * instance exceed 255.
73 * @exception NegativeArraySizeException if the specified {@code length}
74 * is negative
75 */
76 public static Object newInstance(Class<?> componentType, int length)
77 throws NegativeArraySizeException {
78 return newArray(componentType, length);
79 }
80
81 /**
82 * Creates a new array
83 * with the specified component type and dimensions.
84 * If {@code componentType}
85 * represents a non-array class or interface, the new array
86 * has {@code dimensions.length} dimensions and
87 * {@code componentType} as its component type. If
88 * {@code componentType} represents an array class, the
89 * number of dimensions of the new array is equal to the sum
90 * of {@code dimensions.length} and the number of
91 * dimensions of {@code componentType}. In this case, the
92 * component type of the new array is the component type of
93 * {@code componentType}.
94 *
95 * <p>The number of dimensions of the new array must not
96 * exceed 255.
97 *
98 * @param componentType the {@code Class} object representing the component
99 * type of the new array
100 * @param dimensions an array of {@code int} representing the dimensions of
101 * the new array
102 * @return the new array
103 * @exception NullPointerException if the specified
104 * {@code componentType} argument is null
105 * @exception IllegalArgumentException if the specified {@code dimensions}
106 * argument is a zero-dimensional array, if componentType is {@link
107 * Void#TYPE}, or if the number of dimensions of the requested array
108 * instance exceed 255.
109 * @exception NegativeArraySizeException if any of the components in
110 * the specified {@code dimensions} argument is negative.
111 */
112 public static Object newInstance(Class<?> componentType, int... dimensions)
113 throws IllegalArgumentException, NegativeArraySizeException {
114 return multiNewArray(componentType, dimensions);
115 }
116
117 /**
118 * Returns the length of the specified array object, as an {@code int}.
119 *
120 * @param array the array
121 * @return the length of the array
122 * @exception IllegalArgumentException if the object argument is not
123 * an array
124 */
125 @HotSpotIntrinsicCandidate
126 public static native int getLength(Object array)
127 throws IllegalArgumentException;
128
129 /**
130 * Returns the value of the indexed component in the specified
131 * array object. The value is automatically wrapped in an object
132 * if it has a primitive type.
133 *
134 * @param array the array
135 * @param index the index
136 * @return the (possibly wrapped) value of the indexed component in
137 * the specified array
138 * @exception NullPointerException If the specified object is null
139 * @exception IllegalArgumentException If the specified object is not
140 * an array
141 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
142 * argument is negative, or if it is greater than or equal to the
143 * length of the specified array
144 */
145 public static native Object get(Object array, int index)
146 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
147
148 /**
149 * Returns the value of the indexed component in the specified
150 * array object, as a {@code boolean}.
151 *
152 * @param array the array
153 * @param index the index
154 * @return the value of the indexed component in the specified array
155 * @exception NullPointerException If the specified object is null
156 * @exception IllegalArgumentException If the specified object is not
157 * an array, or if the indexed element cannot be converted to the
158 * return type by an identity or widening conversion
159 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
160 * argument is negative, or if it is greater than or equal to the
161 * length of the specified array
162 * @see Array#get
163 */
164 public static native boolean getBoolean(Object array, int index)
165 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
166
167 /**
168 * Returns the value of the indexed component in the specified
169 * array object, as a {@code byte}.
170 *
171 * @param array the array
172 * @param index the index
173 * @return the value of the indexed component in the specified array
174 * @exception NullPointerException If the specified object is null
175 * @exception IllegalArgumentException If the specified object is not
176 * an array, or if the indexed element cannot be converted to the
177 * return type by an identity or widening conversion
178 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
179 * argument is negative, or if it is greater than or equal to the
180 * length of the specified array
181 * @see Array#get
182 */
183 public static native byte getByte(Object array, int index)
184 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
185
186 /**
187 * Returns the value of the indexed component in the specified
188 * array object, as a {@code char}.
189 *
190 * @param array the array
191 * @param index the index
192 * @return the value of the indexed component in the specified array
193 * @exception NullPointerException If the specified object is null
194 * @exception IllegalArgumentException If the specified object is not
195 * an array, or if the indexed element cannot be converted to the
196 * return type by an identity or widening conversion
197 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
198 * argument is negative, or if it is greater than or equal to the
199 * length of the specified array
200 * @see Array#get
201 */
202 public static native char getChar(Object array, int index)
203 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
204
205 /**
206 * Returns the value of the indexed component in the specified
207 * array object, as a {@code short}.
208 *
209 * @param array the array
210 * @param index the index
211 * @return the value of the indexed component in the specified array
212 * @exception NullPointerException If the specified object is null
213 * @exception IllegalArgumentException If the specified object is not
214 * an array, or if the indexed element cannot be converted to the
215 * return type by an identity or widening conversion
216 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
217 * argument is negative, or if it is greater than or equal to the
218 * length of the specified array
219 * @see Array#get
220 */
221 public static native short getShort(Object array, int index)
222 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
223
224 /**
225 * Returns the value of the indexed component in the specified
226 * array object, as an {@code int}.
227 *
228 * @param array the array
229 * @param index the index
230 * @return the value of the indexed component in the specified array
231 * @exception NullPointerException If the specified object is null
232 * @exception IllegalArgumentException If the specified object is not
233 * an array, or if the indexed element cannot be converted to the
234 * return type by an identity or widening conversion
235 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
236 * argument is negative, or if it is greater than or equal to the
237 * length of the specified array
238 * @see Array#get
239 */
240 public static native int getInt(Object array, int index)
241 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
242
243 /**
244 * Returns the value of the indexed component in the specified
245 * array object, as a {@code long}.
246 *
247 * @param array the array
248 * @param index the index
249 * @return the value of the indexed component in the specified array
250 * @exception NullPointerException If the specified object is null
251 * @exception IllegalArgumentException If the specified object is not
252 * an array, or if the indexed element cannot be converted to the
253 * return type by an identity or widening conversion
254 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
255 * argument is negative, or if it is greater than or equal to the
256 * length of the specified array
257 * @see Array#get
258 */
259 public static native long getLong(Object array, int index)
260 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
261
262 /**
263 * Returns the value of the indexed component in the specified
264 * array object, as a {@code float}.
265 *
266 * @param array the array
267 * @param index the index
268 * @return the value of the indexed component in the specified array
269 * @exception NullPointerException If the specified object is null
270 * @exception IllegalArgumentException If the specified object is not
271 * an array, or if the indexed element cannot be converted to the
272 * return type by an identity or widening conversion
273 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
274 * argument is negative, or if it is greater than or equal to the
275 * length of the specified array
276 * @see Array#get
277 */
278 public static native float getFloat(Object array, int index)
279 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
280
281 /**
282 * Returns the value of the indexed component in the specified
283 * array object, as a {@code double}.
284 *
285 * @param array the array
286 * @param index the index
287 * @return the value of the indexed component in the specified array
288 * @exception NullPointerException If the specified object is null
289 * @exception IllegalArgumentException If the specified object is not
290 * an array, or if the indexed element cannot be converted to the
291 * return type by an identity or widening conversion
292 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
293 * argument is negative, or if it is greater than or equal to the
294 * length of the specified array
295 * @see Array#get
296 */
297 public static native double getDouble(Object array, int index)
298 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
299
300 /**
301 * Sets the value of the indexed component of the specified array
302 * object to the specified new value. The new value is first
303 * automatically unwrapped if the array has a primitive component
304 * type.
305 * @param array the array
306 * @param index the index into the array
307 * @param value the new value of the indexed component
308 * @exception NullPointerException If the specified object argument
309 * is null
310 * @exception IllegalArgumentException If the specified object argument
311 * is not an array, or if the array component type is primitive and
312 * an unwrapping conversion fails
313 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
314 * argument is negative, or if it is greater than or equal to
315 * the length of the specified array
316 */
317 public static native void set(Object array, int index, Object value)
318 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
319
320 /**
321 * Sets the value of the indexed component of the specified array
322 * object to the specified {@code boolean} value.
323 * @param array the array
324 * @param index the index into the array
325 * @param z the new value of the indexed component
326 * @exception NullPointerException If the specified object argument
327 * is null
328 * @exception IllegalArgumentException If the specified object argument
329 * is not an array, or if the specified value cannot be converted
330 * to the underlying array's component type by an identity or a
331 * primitive widening conversion
332 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
333 * argument is negative, or if it is greater than or equal to
334 * the length of the specified array
335 * @see Array#set
336 */
337 public static native void setBoolean(Object array, int index, boolean z)
338 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
339
340 /**
341 * Sets the value of the indexed component of the specified array
342 * object to the specified {@code byte} value.
343 * @param array the array
344 * @param index the index into the array
345 * @param b the new value of the indexed component
346 * @exception NullPointerException If the specified object argument
347 * is null
348 * @exception IllegalArgumentException If the specified object argument
349 * is not an array, or if the specified value cannot be converted
350 * to the underlying array's component type by an identity or a
351 * primitive widening conversion
352 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
353 * argument is negative, or if it is greater than or equal to
354 * the length of the specified array
355 * @see Array#set
356 */
357 public static native void setByte(Object array, int index, byte b)
358 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
359
360 /**
361 * Sets the value of the indexed component of the specified array
362 * object to the specified {@code char} value.
363 * @param array the array
364 * @param index the index into the array
365 * @param c the new value of the indexed component
366 * @exception NullPointerException If the specified object argument
367 * is null
368 * @exception IllegalArgumentException If the specified object argument
369 * is not an array, or if the specified value cannot be converted
370 * to the underlying array's component type by an identity or a
371 * primitive widening conversion
372 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
373 * argument is negative, or if it is greater than or equal to
374 * the length of the specified array
375 * @see Array#set
376 */
377 public static native void setChar(Object array, int index, char c)
378 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
379
380 /**
381 * Sets the value of the indexed component of the specified array
382 * object to the specified {@code short} value.
383 * @param array the array
384 * @param index the index into the array
385 * @param s the new value of the indexed component
386 * @exception NullPointerException If the specified object argument
387 * is null
388 * @exception IllegalArgumentException If the specified object argument
389 * is not an array, or if the specified value cannot be converted
390 * to the underlying array's component type by an identity or a
391 * primitive widening conversion
392 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
393 * argument is negative, or if it is greater than or equal to
394 * the length of the specified array
395 * @see Array#set
396 */
397 public static native void setShort(Object array, int index, short s)
398 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
399
400 /**
401 * Sets the value of the indexed component of the specified array
402 * object to the specified {@code int} value.
403 * @param array the array
404 * @param index the index into the array
405 * @param i the new value of the indexed component
406 * @exception NullPointerException If the specified object argument
407 * is null
408 * @exception IllegalArgumentException If the specified object argument
409 * is not an array, or if the specified value cannot be converted
410 * to the underlying array's component type by an identity or a
411 * primitive widening conversion
412 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
413 * argument is negative, or if it is greater than or equal to
414 * the length of the specified array
415 * @see Array#set
416 */
417 public static native void setInt(Object array, int index, int i)
418 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
419
420 /**
421 * Sets the value of the indexed component of the specified array
422 * object to the specified {@code long} value.
423 * @param array the array
424 * @param index the index into the array
425 * @param l the new value of the indexed component
426 * @exception NullPointerException If the specified object argument
427 * is null
428 * @exception IllegalArgumentException If the specified object argument
429 * is not an array, or if the specified value cannot be converted
430 * to the underlying array's component type by an identity or a
431 * primitive widening conversion
432 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
433 * argument is negative, or if it is greater than or equal to
434 * the length of the specified array
435 * @see Array#set
436 */
437 public static native void setLong(Object array, int index, long l)
438 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
439
440 /**
441 * Sets the value of the indexed component of the specified array
442 * object to the specified {@code float} value.
443 * @param array the array
444 * @param index the index into the array
445 * @param f the new value of the indexed component
446 * @exception NullPointerException If the specified object argument
447 * is null
448 * @exception IllegalArgumentException If the specified object argument
449 * is not an array, or if the specified value cannot be converted
450 * to the underlying array's component type by an identity or a
451 * primitive widening conversion
452 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
453 * argument is negative, or if it is greater than or equal to
454 * the length of the specified array
455 * @see Array#set
456 */
457 public static native void setFloat(Object array, int index, float f)
458 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
459
460 /**
461 * Sets the value of the indexed component of the specified array
462 * object to the specified {@code double} value.
463 * @param array the array
464 * @param index the index into the array
465 * @param d the new value of the indexed component
466 * @exception NullPointerException If the specified object argument
467 * is null
468 * @exception IllegalArgumentException If the specified object argument
469 * is not an array, or if the specified value cannot be converted
470 * to the underlying array's component type by an identity or a
471 * primitive widening conversion
472 * @exception ArrayIndexOutOfBoundsException If the specified {@code index}
473 * argument is negative, or if it is greater than or equal to
474 * the length of the specified array
475 * @see Array#set
476 */
477 public static native void setDouble(Object array, int index, double d)
478 throws IllegalArgumentException, ArrayIndexOutOfBoundsException;
479
480 /*
481 * Private
482 */
483
484 @HotSpotIntrinsicCandidate
485 private static native Object newArray(Class<?> componentType, int length)
486 throws NegativeArraySizeException;
487
488 private static native Object multiNewArray(Class<?> componentType,
489 int[] dimensions)
490 throws IllegalArgumentException, NegativeArraySizeException;
491
492
493 }