001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.lang3; 018 019import java.io.IOException; 020import java.io.Serializable; 021import java.lang.reflect.Array; 022import java.time.Duration; 023import java.util.ArrayList; 024import java.util.Collection; 025import java.util.Collections; 026import java.util.Comparator; 027import java.util.HashMap; 028import java.util.Hashtable; 029import java.util.Map; 030import java.util.Objects; 031import java.util.Optional; 032import java.util.TreeSet; 033import java.util.function.Supplier; 034import java.util.stream.Stream; 035 036import org.apache.commons.lang3.exception.CloneFailedException; 037import org.apache.commons.lang3.function.Suppliers; 038import org.apache.commons.lang3.mutable.MutableInt; 039import org.apache.commons.lang3.stream.Streams; 040import org.apache.commons.lang3.text.StrBuilder; 041import org.apache.commons.lang3.time.DurationUtils; 042 043/** 044 * Operations on {@link Object}. 045 * 046 * <p>This class tries to handle {@code null} input gracefully. 047 * An exception will generally not be thrown for a {@code null} input. 048 * Each method documents its behavior in more detail.</p> 049 * 050 * <p>#ThreadSafe#</p> 051 * @since 1.0 052 */ 053//@Immutable 054@SuppressWarnings("deprecation") // deprecated class StrBuilder is imported 055// because it is part of the signature of deprecated methods 056public class ObjectUtils { 057 058 /** 059 * Class used as a null placeholder where {@code null} 060 * has another meaning. 061 * 062 * <p>For example, in a {@link HashMap} the 063 * {@link java.util.HashMap#get(Object)} method returns 064 * {@code null} if the {@link Map} contains {@code null} or if there is 065 * no matching key. The {@code null} placeholder can be used to distinguish 066 * between these two cases.</p> 067 * 068 * <p>Another example is {@link Hashtable}, where {@code null} 069 * cannot be stored.</p> 070 */ 071 public static class Null implements Serializable { 072 /** 073 * Required for serialization support. Declare serialization compatibility with Commons Lang 1.0 074 * 075 * @see java.io.Serializable 076 */ 077 private static final long serialVersionUID = 7092611880189329093L; 078 079 /** 080 * Restricted constructor - singleton. 081 */ 082 Null() { 083 } 084 085 /** 086 * Ensure Singleton after serialization. 087 * 088 * @return the singleton value 089 */ 090 private Object readResolve() { 091 return NULL; 092 } 093 } 094 095 private static final char AT_SIGN = '@'; 096 097 /** 098 * Singleton used as a {@code null} placeholder where 099 * {@code null} has another meaning. 100 * 101 * <p>For example, in a {@link HashMap} the 102 * {@link java.util.HashMap#get(Object)} method returns 103 * {@code null} if the {@link Map} contains {@code null} or if there 104 * is no matching key. The {@code null} placeholder can be used to 105 * distinguish between these two cases.</p> 106 * 107 * <p>Another example is {@link Hashtable}, where {@code null} 108 * cannot be stored.</p> 109 * 110 * <p>This instance is Serializable.</p> 111 */ 112 public static final Null NULL = new Null(); 113 114 /** 115 * Tests if all values in the array are not {@code nulls}. 116 * 117 * <p> 118 * If any value is {@code null} or the array is {@code null} then 119 * {@code false} is returned. If all elements in array are not 120 * {@code null} or the array is empty (contains no elements) {@code true} 121 * is returned. 122 * </p> 123 * 124 * <pre> 125 * ObjectUtils.allNotNull(*) = true 126 * ObjectUtils.allNotNull(*, *) = true 127 * ObjectUtils.allNotNull(null) = false 128 * ObjectUtils.allNotNull(null, null) = false 129 * ObjectUtils.allNotNull(null, *) = false 130 * ObjectUtils.allNotNull(*, null) = false 131 * ObjectUtils.allNotNull(*, *, null, *) = false 132 * </pre> 133 * 134 * @param values the values to test, may be {@code null} or empty 135 * @return {@code false} if there is at least one {@code null} value in the array or the array is {@code null}, 136 * {@code true} if all values in the array are not {@code null}s or array contains no elements. 137 * @since 3.5 138 */ 139 public static boolean allNotNull(final Object... values) { 140 return values != null && Stream.of(values).noneMatch(Objects::isNull); 141 } 142 143 /** 144 * Tests if all values in the given array are {@code null}. 145 * 146 * <p> 147 * If all the values are {@code null} or the array is {@code null} 148 * or empty, then {@code true} is returned, otherwise {@code false} is returned. 149 * </p> 150 * 151 * <pre> 152 * ObjectUtils.allNull(*) = false 153 * ObjectUtils.allNull(*, null) = false 154 * ObjectUtils.allNull(null, *) = false 155 * ObjectUtils.allNull(null, null, *, *) = false 156 * ObjectUtils.allNull(null) = true 157 * ObjectUtils.allNull(null, null) = true 158 * </pre> 159 * 160 * @param values the values to test, may be {@code null} or empty 161 * @return {@code true} if all values in the array are {@code null}s, 162 * {@code false} if there is at least one non-null value in the array. 163 * @since 3.11 164 */ 165 public static boolean allNull(final Object... values) { 166 return !anyNotNull(values); 167 } 168 169 /** 170 * Tests if any value in the given array is not {@code null}. 171 * 172 * <p> 173 * If all the values are {@code null} or the array is {@code null} 174 * or empty then {@code false} is returned. Otherwise {@code true} is returned. 175 * </p> 176 * 177 * <pre> 178 * ObjectUtils.anyNotNull(*) = true 179 * ObjectUtils.anyNotNull(*, null) = true 180 * ObjectUtils.anyNotNull(null, *) = true 181 * ObjectUtils.anyNotNull(null, null, *, *) = true 182 * ObjectUtils.anyNotNull(null) = false 183 * ObjectUtils.anyNotNull(null, null) = false 184 * </pre> 185 * 186 * @param values the values to test, may be {@code null} or empty 187 * @return {@code true} if there is at least one non-null value in the array, 188 * {@code false} if all values in the array are {@code null}s. 189 * If the array is {@code null} or empty {@code false} is also returned. 190 * @since 3.5 191 */ 192 public static boolean anyNotNull(final Object... values) { 193 return firstNonNull(values) != null; 194 } 195 196 /** 197 * Tests if any value in the given array is {@code null}. 198 * 199 * <p> 200 * If any of the values are {@code null} or the array is {@code null}, 201 * then {@code true} is returned, otherwise {@code false} is returned. 202 * </p> 203 * 204 * <pre> 205 * ObjectUtils.anyNull(*) = false 206 * ObjectUtils.anyNull(*, *) = false 207 * ObjectUtils.anyNull(null) = true 208 * ObjectUtils.anyNull(null, null) = true 209 * ObjectUtils.anyNull(null, *) = true 210 * ObjectUtils.anyNull(*, null) = true 211 * ObjectUtils.anyNull(*, *, null, *) = true 212 * </pre> 213 * 214 * @param values the values to test, may be {@code null} or empty 215 * @return {@code true} if there is at least one {@code null} value in the array, 216 * {@code false} if all the values are non-null. 217 * If the array is {@code null} or empty, {@code true} is also returned. 218 * @since 3.11 219 */ 220 public static boolean anyNull(final Object... values) { 221 return !allNotNull(values); 222 } 223 224 /** 225 * Clones an object. 226 * 227 * @param <T> the type of the object 228 * @param obj the object to clone, null returns null 229 * @return the clone if the object implements {@link Cloneable} otherwise {@code null} 230 * @throws CloneFailedException if the object is cloneable and the clone operation fails 231 * @since 3.0 232 */ 233 public static <T> T clone(final T obj) { 234 if (obj instanceof Cloneable) { 235 final Object result; 236 final Class<? extends Object> objClass = obj.getClass(); 237 if (isArray(obj)) { 238 final Class<?> componentType = objClass.getComponentType(); 239 if (componentType.isPrimitive()) { 240 int length = Array.getLength(obj); 241 result = Array.newInstance(componentType, length); 242 while (length-- > 0) { 243 Array.set(result, length, Array.get(obj, length)); 244 } 245 } else { 246 result = ((Object[]) obj).clone(); 247 } 248 } else { 249 try { 250 result = objClass.getMethod("clone").invoke(obj); 251 } catch (final ReflectiveOperationException e) { 252 throw new CloneFailedException("Exception cloning Cloneable type " + objClass.getName(), e); 253 } 254 } 255 return (T) result; 256 } 257 258 return null; 259 } 260 261 /** 262 * Clones an object if possible. 263 * 264 * <p>This method is similar to {@link #clone(Object)}, but will return the provided 265 * instance as the return value instead of {@code null} if the instance 266 * is not cloneable. This is more convenient if the caller uses different 267 * implementations (e.g. of a service) and some of the implementations do not allow concurrent 268 * processing or have state. In such cases the implementation can simply provide a proper 269 * clone implementation and the caller's code does not have to change.</p> 270 * 271 * @param <T> the type of the object 272 * @param obj the object to clone, null returns null 273 * @return the clone if the object implements {@link Cloneable} otherwise the object itself 274 * @throws CloneFailedException if the object is cloneable and the clone operation fails 275 * @since 3.0 276 */ 277 public static <T> T cloneIfPossible(final T obj) { 278 final T clone = clone(obj); 279 return clone == null ? obj : clone; 280 } 281 282 /** 283 * Null safe comparison of Comparables. 284 * {@code null} is assumed to be less than a non-{@code null} value. 285 * <p>TODO Move to ComparableUtils.</p> 286 * 287 * @param <T> type of the values processed by this method 288 * @param c1 the first comparable, may be null 289 * @param c2 the second comparable, may be null 290 * @return a negative value if c1 < c2, zero if c1 = c2 291 * and a positive value if c1 > c2 292 */ 293 public static <T extends Comparable<? super T>> int compare(final T c1, final T c2) { 294 return compare(c1, c2, false); 295 } 296 297 /** 298 * Null safe comparison of Comparables. 299 * <p>TODO Move to ComparableUtils.</p> 300 * 301 * @param <T> type of the values processed by this method 302 * @param c1 the first comparable, may be null 303 * @param c2 the second comparable, may be null 304 * @param nullGreater if true {@code null} is considered greater 305 * than a non-{@code null} value or if false {@code null} is 306 * considered less than a Non-{@code null} value 307 * @return a negative value if c1 < c2, zero if c1 = c2 308 * and a positive value if c1 > c2 309 * @see java.util.Comparator#compare(Object, Object) 310 */ 311 public static <T extends Comparable<? super T>> int compare(final T c1, final T c2, final boolean nullGreater) { 312 if (c1 == c2) { 313 return 0; 314 } 315 if (c1 == null) { 316 return nullGreater ? 1 : -1; 317 } 318 if (c2 == null) { 319 return nullGreater ? -1 : 1; 320 } 321 return c1.compareTo(c2); 322 } 323 324 /** 325 * Returns the provided value unchanged. 326 * This can prevent javac from inlining a constant 327 * field, e.g., 328 * 329 * <pre> 330 * public final static boolean MAGIC_FLAG = ObjectUtils.CONST(true); 331 * </pre> 332 * 333 * This way any jars that refer to this field do not 334 * have to recompile themselves if the field's value 335 * changes at some future date. 336 * 337 * @param v the boolean value to return 338 * @return the boolean v, unchanged 339 * @since 3.2 340 */ 341 public static boolean CONST(final boolean v) { 342 return v; 343 } 344 345 /** 346 * Returns the provided value unchanged. 347 * This can prevent javac from inlining a constant 348 * field, e.g., 349 * 350 * <pre> 351 * public final static byte MAGIC_BYTE = ObjectUtils.CONST((byte) 127); 352 * </pre> 353 * 354 * This way any jars that refer to this field do not 355 * have to recompile themselves if the field's value 356 * changes at some future date. 357 * 358 * @param v the byte value to return 359 * @return the byte v, unchanged 360 * @since 3.2 361 */ 362 public static byte CONST(final byte v) { 363 return v; 364 } 365 366 /** 367 * Returns the provided value unchanged. 368 * This can prevent javac from inlining a constant 369 * field, e.g., 370 * 371 * <pre> 372 * public final static char MAGIC_CHAR = ObjectUtils.CONST('a'); 373 * </pre> 374 * 375 * This way any jars that refer to this field do not 376 * have to recompile themselves if the field's value 377 * changes at some future date. 378 * 379 * @param v the char value to return 380 * @return the char v, unchanged 381 * @since 3.2 382 */ 383 public static char CONST(final char v) { 384 return v; 385 } 386 387 /** 388 * Returns the provided value unchanged. 389 * This can prevent javac from inlining a constant 390 * field, e.g., 391 * 392 * <pre> 393 * public final static double MAGIC_DOUBLE = ObjectUtils.CONST(1.0); 394 * </pre> 395 * 396 * This way any jars that refer to this field do not 397 * have to recompile themselves if the field's value 398 * changes at some future date. 399 * 400 * @param v the double value to return 401 * @return the double v, unchanged 402 * @since 3.2 403 */ 404 public static double CONST(final double v) { 405 return v; 406 } 407 408 /** 409 * Returns the provided value unchanged. 410 * This can prevent javac from inlining a constant 411 * field, e.g., 412 * 413 * <pre> 414 * public final static float MAGIC_FLOAT = ObjectUtils.CONST(1.0f); 415 * </pre> 416 * 417 * This way any jars that refer to this field do not 418 * have to recompile themselves if the field's value 419 * changes at some future date. 420 * 421 * @param v the float value to return 422 * @return the float v, unchanged 423 * @since 3.2 424 */ 425 public static float CONST(final float v) { 426 return v; 427 } 428 429 /** 430 * Returns the provided value unchanged. 431 * This can prevent javac from inlining a constant 432 * field, e.g., 433 * 434 * <pre> 435 * public final static int MAGIC_INT = ObjectUtils.CONST(123); 436 * </pre> 437 * 438 * This way any jars that refer to this field do not 439 * have to recompile themselves if the field's value 440 * changes at some future date. 441 * 442 * @param v the int value to return 443 * @return the int v, unchanged 444 * @since 3.2 445 */ 446 public static int CONST(final int v) { 447 return v; 448 } 449 450 /** 451 * Returns the provided value unchanged. 452 * This can prevent javac from inlining a constant 453 * field, e.g., 454 * 455 * <pre> 456 * public final static long MAGIC_LONG = ObjectUtils.CONST(123L); 457 * </pre> 458 * 459 * This way any jars that refer to this field do not 460 * have to recompile themselves if the field's value 461 * changes at some future date. 462 * 463 * @param v the long value to return 464 * @return the long v, unchanged 465 * @since 3.2 466 */ 467 public static long CONST(final long v) { 468 return v; 469 } 470 471 /** 472 * Returns the provided value unchanged. 473 * This can prevent javac from inlining a constant 474 * field, e.g., 475 * 476 * <pre> 477 * public final static short MAGIC_SHORT = ObjectUtils.CONST((short) 123); 478 * </pre> 479 * 480 * This way any jars that refer to this field do not 481 * have to recompile themselves if the field's value 482 * changes at some future date. 483 * 484 * @param v the short value to return 485 * @return the short v, unchanged 486 * @since 3.2 487 */ 488 public static short CONST(final short v) { 489 return v; 490 } 491 492 /** 493 * Returns the provided value unchanged. 494 * This can prevent javac from inlining a constant 495 * field, e.g., 496 * 497 * <pre> 498 * public final static String MAGIC_STRING = ObjectUtils.CONST("abc"); 499 * </pre> 500 * 501 * This way any jars that refer to this field do not 502 * have to recompile themselves if the field's value 503 * changes at some future date. 504 * 505 * @param <T> the Object type 506 * @param v the genericized Object value to return (typically a String). 507 * @return the genericized Object v, unchanged (typically a String). 508 * @since 3.2 509 */ 510 public static <T> T CONST(final T v) { 511 return v; 512 } 513 514 /** 515 * Returns the provided value unchanged. 516 * This can prevent javac from inlining a constant 517 * field, e.g., 518 * 519 * <pre> 520 * public final static byte MAGIC_BYTE = ObjectUtils.CONST_BYTE(127); 521 * </pre> 522 * 523 * This way any jars that refer to this field do not 524 * have to recompile themselves if the field's value 525 * changes at some future date. 526 * 527 * @param v the byte literal (as an int) value to return 528 * @throws IllegalArgumentException if the value passed to v 529 * is larger than a byte, that is, smaller than -128 or 530 * larger than 127. 531 * @return the byte v, unchanged 532 * @since 3.2 533 */ 534 public static byte CONST_BYTE(final int v) { 535 if (v < Byte.MIN_VALUE || v > Byte.MAX_VALUE) { 536 throw new IllegalArgumentException("Supplied value must be a valid byte literal between -128 and 127: [" + v + "]"); 537 } 538 return (byte) v; 539 } 540 541 /** 542 * Returns the provided value unchanged. 543 * This can prevent javac from inlining a constant 544 * field, e.g., 545 * 546 * <pre> 547 * public final static short MAGIC_SHORT = ObjectUtils.CONST_SHORT(127); 548 * </pre> 549 * 550 * This way any jars that refer to this field do not 551 * have to recompile themselves if the field's value 552 * changes at some future date. 553 * 554 * @param v the short literal (as an int) value to return 555 * @throws IllegalArgumentException if the value passed to v 556 * is larger than a short, that is, smaller than -32768 or 557 * larger than 32767. 558 * @return the byte v, unchanged 559 * @since 3.2 560 */ 561 public static short CONST_SHORT(final int v) { 562 if (v < Short.MIN_VALUE || v > Short.MAX_VALUE) { 563 throw new IllegalArgumentException("Supplied value must be a valid byte literal between -32768 and 32767: [" + v + "]"); 564 } 565 return (short) v; 566 } 567 568 /** 569 * Returns a default value if the object passed is {@code null}. 570 * 571 * <pre> 572 * ObjectUtils.defaultIfNull(null, null) = null 573 * ObjectUtils.defaultIfNull(null, "") = "" 574 * ObjectUtils.defaultIfNull(null, "zz") = "zz" 575 * ObjectUtils.defaultIfNull("abc", *) = "abc" 576 * ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE 577 * </pre> 578 * 579 * @param <T> the type of the object 580 * @param object the {@link Object} to test, may be {@code null} 581 * @param defaultValue the default value to return, may be {@code null} 582 * @return {@code object} if it is not {@code null}, defaultValue otherwise 583 * TODO Rename to getIfNull in 4.0 584 */ 585 public static <T> T defaultIfNull(final T object, final T defaultValue) { 586 return object != null ? object : defaultValue; 587 } 588 589 // Null-safe equals/hashCode 590 /** 591 * Compares two objects for equality, where either one or both 592 * objects may be {@code null}. 593 * 594 * <pre> 595 * ObjectUtils.equals(null, null) = true 596 * ObjectUtils.equals(null, "") = false 597 * ObjectUtils.equals("", null) = false 598 * ObjectUtils.equals("", "") = true 599 * ObjectUtils.equals(Boolean.TRUE, null) = false 600 * ObjectUtils.equals(Boolean.TRUE, "true") = false 601 * ObjectUtils.equals(Boolean.TRUE, Boolean.TRUE) = true 602 * ObjectUtils.equals(Boolean.TRUE, Boolean.FALSE) = false 603 * </pre> 604 * 605 * @param object1 the first object, may be {@code null} 606 * @param object2 the second object, may be {@code null} 607 * @return {@code true} if the values of both objects are the same 608 * @deprecated this method has been replaced by {@code java.util.Objects.equals(Object, Object)} in Java 7 and will 609 * be removed from future releases. 610 */ 611 @Deprecated 612 public static boolean equals(final Object object1, final Object object2) { 613 return Objects.equals(object1, object2); 614 } 615 616 /** 617 * Returns the first value in the array which is not {@code null}. 618 * If all the values are {@code null} or the array is {@code null} 619 * or empty then {@code null} is returned. 620 * 621 * <pre> 622 * ObjectUtils.firstNonNull(null, null) = null 623 * ObjectUtils.firstNonNull(null, "") = "" 624 * ObjectUtils.firstNonNull(null, null, "") = "" 625 * ObjectUtils.firstNonNull(null, "zz") = "zz" 626 * ObjectUtils.firstNonNull("abc", *) = "abc" 627 * ObjectUtils.firstNonNull(null, "xyz", *) = "xyz" 628 * ObjectUtils.firstNonNull(Boolean.TRUE, *) = Boolean.TRUE 629 * ObjectUtils.firstNonNull() = null 630 * </pre> 631 * 632 * @param <T> the component type of the array 633 * @param values the values to test, may be {@code null} or empty 634 * @return the first value from {@code values} which is not {@code null}, 635 * or {@code null} if there are no non-null values 636 * @since 3.0 637 */ 638 @SafeVarargs 639 public static <T> T firstNonNull(final T... values) { 640 return Streams.of(values).filter(Objects::nonNull).findFirst().orElse(null); 641 } 642 643 /** 644 * Delegates to {@link Object#getClass()} using generics. 645 * 646 * @param <T> The argument type or null. 647 * @param object The argument. 648 * @return The argument's Class or null. 649 * @since 3.13.0 650 */ 651 @SuppressWarnings("unchecked") 652 public static <T> Class<T> getClass(final T object) { 653 return object == null ? null : (Class<T>) object.getClass(); 654 } 655 656 /** 657 * Executes the given suppliers in order and returns the first return 658 * value where a value other than {@code null} is returned. 659 * Once a non-{@code null} value is obtained, all following suppliers are 660 * not executed anymore. 661 * If all the return values are {@code null} or no suppliers are provided 662 * then {@code null} is returned. 663 * 664 * <pre> 665 * ObjectUtils.firstNonNullLazy(null, () -> null) = null 666 * ObjectUtils.firstNonNullLazy(() -> null, () -> "") = "" 667 * ObjectUtils.firstNonNullLazy(() -> "", () -> throw new IllegalStateException()) = "" 668 * ObjectUtils.firstNonNullLazy(() -> null, () -> "zz) = "zz" 669 * ObjectUtils.firstNonNullLazy() = null 670 * </pre> 671 * 672 * @param <T> the type of the return values 673 * @param suppliers the suppliers returning the values to test. 674 * {@code null} values are ignored. 675 * Suppliers may return {@code null} or a value of type {@code T} 676 * @return the first return value from {@code suppliers} which is not {@code null}, 677 * or {@code null} if there are no non-null values 678 * @since 3.10 679 */ 680 @SafeVarargs 681 public static <T> T getFirstNonNull(final Supplier<T>... suppliers) { 682 return Streams.of(suppliers).filter(Objects::nonNull).map(Supplier::get).filter(Objects::nonNull).findFirst().orElse(null); 683 } 684 685 /** 686 * Returns the given {@code object} is it is non-null, otherwise returns the Supplier's {@link Supplier#get()} 687 * value. 688 * 689 * <p> 690 * The caller responsible for thread-safety and exception handling of default value supplier. 691 * </p> 692 * 693 * <pre> 694 * ObjectUtils.getIfNull(null, () -> null) = null 695 * ObjectUtils.getIfNull(null, null) = null 696 * ObjectUtils.getIfNull(null, () -> "") = "" 697 * ObjectUtils.getIfNull(null, () -> "zz") = "zz" 698 * ObjectUtils.getIfNull("abc", *) = "abc" 699 * ObjectUtils.getIfNull(Boolean.TRUE, *) = Boolean.TRUE 700 * </pre> 701 * 702 * @param <T> the type of the object 703 * @param object the {@link Object} to test, may be {@code null} 704 * @param defaultSupplier the default value to return, may be {@code null} 705 * @return {@code object} if it is not {@code null}, {@code defaultValueSupplier.get()} otherwise 706 * @since 3.10 707 */ 708 public static <T> T getIfNull(final T object, final Supplier<T> defaultSupplier) { 709 return object != null ? object : Suppliers.get(defaultSupplier); 710 } 711 712 /** 713 * Gets the hash code of an object returning zero when the 714 * object is {@code null}. 715 * 716 * <pre> 717 * ObjectUtils.hashCode(null) = 0 718 * ObjectUtils.hashCode(obj) = obj.hashCode() 719 * </pre> 720 * 721 * @param obj the object to obtain the hash code of, may be {@code null} 722 * @return the hash code of the object, or zero if null 723 * @since 2.1 724 * @deprecated this method has been replaced by {@code java.util.Objects.hashCode(Object)} in Java 7 and will be 725 * removed in future releases 726 */ 727 @Deprecated 728 public static int hashCode(final Object obj) { 729 // hashCode(Object) for performance vs. hashCodeMulti(Object[]), as hash code is often critical 730 return Objects.hashCode(obj); 731 } 732 733 /** 734 * Returns the hexadecimal hash code for the given object per {@link Objects#hashCode(Object)}. 735 * <p> 736 * Short hand for {@code Integer.toHexString(Objects.hashCode(object))}. 737 * </p> 738 * 739 * @param object object for which the hashCode is to be calculated 740 * @return Hash code in hexadecimal format. 741 * @since 3.13.0 742 */ 743 public static String hashCodeHex(final Object object) { 744 return Integer.toHexString(Objects.hashCode(object)); 745 } 746 747 /** 748 * Gets the hash code for multiple objects. 749 * 750 * <p>This allows a hash code to be rapidly calculated for a number of objects. 751 * The hash code for a single object is the <em>not</em> same as {@link #hashCode(Object)}. 752 * The hash code for multiple objects is the same as that calculated by an 753 * {@link ArrayList} containing the specified objects.</p> 754 * 755 * <pre> 756 * ObjectUtils.hashCodeMulti() = 1 757 * ObjectUtils.hashCodeMulti((Object[]) null) = 1 758 * ObjectUtils.hashCodeMulti(a) = 31 + a.hashCode() 759 * ObjectUtils.hashCodeMulti(a,b) = (31 + a.hashCode()) * 31 + b.hashCode() 760 * ObjectUtils.hashCodeMulti(a,b,c) = ((31 + a.hashCode()) * 31 + b.hashCode()) * 31 + c.hashCode() 761 * </pre> 762 * 763 * @param objects the objects to obtain the hash code of, may be {@code null} 764 * @return the hash code of the objects, or zero if null 765 * @since 3.0 766 * @deprecated this method has been replaced by {@code java.util.Objects.hash(Object...)} in Java 7 and will be 767 * removed in future releases. 768 */ 769 @Deprecated 770 public static int hashCodeMulti(final Object... objects) { 771 int hash = 1; 772 if (objects != null) { 773 for (final Object object : objects) { 774 final int tmpHash = Objects.hashCode(object); 775 hash = hash * 31 + tmpHash; 776 } 777 } 778 return hash; 779 } 780 781 /** 782 * Returns the hexadecimal hash code for the given object per {@link System#identityHashCode(Object)}. 783 * <p> 784 * Short hand for {@code Integer.toHexString(System.identityHashCode(object))}. 785 * </p> 786 * 787 * @param object object for which the hashCode is to be calculated 788 * @return Hash code in hexadecimal format. 789 * @since 3.13.0 790 */ 791 public static String identityHashCodeHex(final Object object) { 792 return Integer.toHexString(System.identityHashCode(object)); 793 } 794 795 /** 796 * Appends the toString that would be produced by {@link Object} 797 * if a class did not override toString itself. {@code null} 798 * will throw a NullPointerException for either of the two parameters. 799 * 800 * <pre> 801 * ObjectUtils.identityToString(appendable, "") = appendable.append("java.lang.String@1e23") 802 * ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa") 803 * ObjectUtils.identityToString(appendable, Boolean.TRUE) = appendable.append("java.lang.Boolean@7fa") 804 * </pre> 805 * 806 * @param appendable the appendable to append to 807 * @param object the object to create a toString for 808 * @throws IOException if an I/O error occurs. 809 * @since 3.2 810 */ 811 public static void identityToString(final Appendable appendable, final Object object) throws IOException { 812 Objects.requireNonNull(object, "object"); 813 appendable.append(object.getClass().getName()) 814 .append(AT_SIGN) 815 .append(identityHashCodeHex(object)); 816 } 817 818 /** 819 * Gets the toString that would be produced by {@link Object} 820 * if a class did not override toString itself. {@code null} 821 * will return {@code null}. 822 * 823 * <pre> 824 * ObjectUtils.identityToString(null) = null 825 * ObjectUtils.identityToString("") = "java.lang.String@1e23" 826 * ObjectUtils.identityToString(Boolean.TRUE) = "java.lang.Boolean@7fa" 827 * </pre> 828 * 829 * @param object the object to create a toString for, may be 830 * {@code null} 831 * @return the default toString text, or {@code null} if 832 * {@code null} passed in 833 */ 834 public static String identityToString(final Object object) { 835 if (object == null) { 836 return null; 837 } 838 final String name = object.getClass().getName(); 839 final String hexString = identityHashCodeHex(object); 840 final StringBuilder builder = new StringBuilder(name.length() + 1 + hexString.length()); 841 // @formatter:off 842 builder.append(name) 843 .append(AT_SIGN) 844 .append(hexString); 845 // @formatter:on 846 return builder.toString(); 847 } 848 849 /** 850 * Appends the toString that would be produced by {@link Object} 851 * if a class did not override toString itself. {@code null} 852 * will throw a NullPointerException for either of the two parameters. 853 * 854 * <pre> 855 * ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23") 856 * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") 857 * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") 858 * </pre> 859 * 860 * @param builder the builder to append to 861 * @param object the object to create a toString for 862 * @since 3.2 863 * @deprecated as of 3.6, because StrBuilder was moved to commons-text, 864 * use one of the other {@code identityToString} methods instead 865 */ 866 @Deprecated 867 public static void identityToString(final StrBuilder builder, final Object object) { 868 Objects.requireNonNull(object, "object"); 869 final String name = object.getClass().getName(); 870 final String hexString = identityHashCodeHex(object); 871 builder.ensureCapacity(builder.length() + name.length() + 1 + hexString.length()); 872 builder.append(name) 873 .append(AT_SIGN) 874 .append(hexString); 875 } 876 877 /** 878 * Appends the toString that would be produced by {@link Object} 879 * if a class did not override toString itself. {@code null} 880 * will throw a NullPointerException for either of the two parameters. 881 * 882 * <pre> 883 * ObjectUtils.identityToString(buf, "") = buf.append("java.lang.String@1e23") 884 * ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa") 885 * ObjectUtils.identityToString(buf, Boolean.TRUE) = buf.append("java.lang.Boolean@7fa") 886 * </pre> 887 * 888 * @param buffer the buffer to append to 889 * @param object the object to create a toString for 890 * @since 2.4 891 */ 892 public static void identityToString(final StringBuffer buffer, final Object object) { 893 Objects.requireNonNull(object, "object"); 894 final String name = object.getClass().getName(); 895 final String hexString = identityHashCodeHex(object); 896 buffer.ensureCapacity(buffer.length() + name.length() + 1 + hexString.length()); 897 buffer.append(name) 898 .append(AT_SIGN) 899 .append(hexString); 900 } 901 902 /** 903 * Appends the toString that would be produced by {@link Object} 904 * if a class did not override toString itself. {@code null} 905 * will throw a NullPointerException for either of the two parameters. 906 * 907 * <pre> 908 * ObjectUtils.identityToString(builder, "") = builder.append("java.lang.String@1e23") 909 * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") 910 * ObjectUtils.identityToString(builder, Boolean.TRUE) = builder.append("java.lang.Boolean@7fa") 911 * </pre> 912 * 913 * @param builder the builder to append to 914 * @param object the object to create a toString for 915 * @since 3.2 916 */ 917 public static void identityToString(final StringBuilder builder, final Object object) { 918 Objects.requireNonNull(object, "object"); 919 final String name = object.getClass().getName(); 920 final String hexString = identityHashCodeHex(object); 921 builder.ensureCapacity(builder.length() + name.length() + 1 + hexString.length()); 922 builder.append(name) 923 .append(AT_SIGN) 924 .append(hexString); 925 } 926 927 // Constants (LANG-816): 928 /* 929 These methods ensure constants are not inlined by javac. 930 For example, typically a developer might declare a constant like so: 931 932 public final static int MAGIC_NUMBER = 5; 933 934 Should a different jar file refer to this, and the MAGIC_NUMBER 935 is changed a later date (e.g., MAGIC_NUMBER = 6), the different jar 936 file will need to recompile itself. This is because javac 937 typically inlines the primitive or String constant directly into 938 the bytecode, and removes the reference to the MAGIC_NUMBER field. 939 940 To help the other jar (so that it does not need to recompile 941 when constants are changed) the original developer can declare 942 their constant using one of the CONST() utility methods, instead: 943 944 public final static int MAGIC_NUMBER = CONST(5); 945 */ 946 947 /** 948 * Tests whether the given object is an Object array or a primitive array in a null-safe manner. 949 * 950 * <p> 951 * A {@code null} {@code object} Object will return {@code false}. 952 * </p> 953 * 954 * <pre> 955 * ObjectUtils.isArray(null) = false 956 * ObjectUtils.isArray("") = false 957 * ObjectUtils.isArray("ab") = false 958 * ObjectUtils.isArray(new int[]{}) = true 959 * ObjectUtils.isArray(new int[]{1,2,3}) = true 960 * ObjectUtils.isArray(1234) = false 961 * </pre> 962 * 963 * @param object the object to check, may be {@code null} 964 * @return {@code true} if the object is an {@code array}, {@code false} otherwise 965 * @since 3.13.0 966 */ 967 public static boolean isArray(final Object object) { 968 return object != null && object.getClass().isArray(); 969 } 970 971 /** 972 * Tests if an Object is empty or null. 973 * 974 * The following types are supported: 975 * <ul> 976 * <li>{@link CharSequence}: Considered empty if its length is zero.</li> 977 * <li>{@link Array}: Considered empty if its length is zero.</li> 978 * <li>{@link Collection}: Considered empty if it has zero elements.</li> 979 * <li>{@link Map}: Considered empty if it has zero key-value mappings.</li> 980 * <li>{@link Optional}: Considered empty if {@link Optional#isPresent} returns false, regardless of the "emptiness" of the contents.</li> 981 * </ul> 982 * 983 * <pre> 984 * ObjectUtils.isEmpty(null) = true 985 * ObjectUtils.isEmpty("") = true 986 * ObjectUtils.isEmpty("ab") = false 987 * ObjectUtils.isEmpty(new int[]{}) = true 988 * ObjectUtils.isEmpty(new int[]{1,2,3}) = false 989 * ObjectUtils.isEmpty(1234) = false 990 * ObjectUtils.isEmpty(1234) = false 991 * ObjectUtils.isEmpty(Optional.of("")) = false 992 * ObjectUtils.isEmpty(Optional.empty()) = true 993 * </pre> 994 * 995 * @param object the {@link Object} to test, may be {@code null} 996 * @return {@code true} if the object has a supported type and is empty or null, 997 * {@code false} otherwise 998 * @since 3.9 999 */ 1000 public static boolean isEmpty(final Object object) { 1001 if (object == null) { 1002 return true; 1003 } 1004 if (object instanceof CharSequence) { 1005 return ((CharSequence) object).length() == 0; 1006 } 1007 if (isArray(object)) { 1008 return Array.getLength(object) == 0; 1009 } 1010 if (object instanceof Collection<?>) { 1011 return ((Collection<?>) object).isEmpty(); 1012 } 1013 if (object instanceof Map<?, ?>) { 1014 return ((Map<?, ?>) object).isEmpty(); 1015 } 1016 if (object instanceof Optional<?>) { 1017 // TODO Java 11 Use Optional#isEmpty() 1018 return !((Optional<?>) object).isPresent(); 1019 } 1020 return false; 1021 } 1022 1023 /** 1024 * Tests if an Object is not empty and not null. 1025 * 1026 * The following types are supported: 1027 * <ul> 1028 * <li>{@link CharSequence}: Considered empty if its length is zero.</li> 1029 * <li>{@link Array}: Considered empty if its length is zero.</li> 1030 * <li>{@link Collection}: Considered empty if it has zero elements.</li> 1031 * <li>{@link Map}: Considered empty if it has zero key-value mappings.</li> 1032 * <li>{@link Optional}: Considered empty if {@link Optional#isPresent} returns false, regardless of the "emptiness" of the contents.</li> 1033 * </ul> 1034 * 1035 * <pre> 1036 * ObjectUtils.isNotEmpty(null) = false 1037 * ObjectUtils.isNotEmpty("") = false 1038 * ObjectUtils.isNotEmpty("ab") = true 1039 * ObjectUtils.isNotEmpty(new int[]{}) = false 1040 * ObjectUtils.isNotEmpty(new int[]{1,2,3}) = true 1041 * ObjectUtils.isNotEmpty(1234) = true 1042 * ObjectUtils.isNotEmpty(Optional.of("")) = true 1043 * ObjectUtils.isNotEmpty(Optional.empty()) = false 1044 * </pre> 1045 * 1046 * @param object the {@link Object} to test, may be {@code null} 1047 * @return {@code true} if the object has an unsupported type or is not empty 1048 * and not null, {@code false} otherwise 1049 * @since 3.9 1050 */ 1051 public static boolean isNotEmpty(final Object object) { 1052 return !isEmpty(object); 1053 } 1054 1055 /** 1056 * Null safe comparison of Comparables. 1057 * <p>TODO Move to ComparableUtils.</p> 1058 * 1059 * @param <T> type of the values processed by this method 1060 * @param values the set of comparable values, may be null 1061 * @return 1062 * <ul> 1063 * <li>If any objects are non-null and unequal, the greater object. 1064 * <li>If all objects are non-null and equal, the first. 1065 * <li>If any of the comparables are null, the greater of the non-null objects. 1066 * <li>If all the comparables are null, null is returned. 1067 * </ul> 1068 */ 1069 @SafeVarargs 1070 public static <T extends Comparable<? super T>> T max(final T... values) { 1071 T result = null; 1072 if (values != null) { 1073 for (final T value : values) { 1074 if (compare(value, result, false) > 0) { 1075 result = value; 1076 } 1077 } 1078 } 1079 return result; 1080 } 1081 1082 /** 1083 * Find the "best guess" middle value among comparables. If there is an even 1084 * number of total values, the lower of the two middle values will be returned. 1085 * @param <T> type of values processed by this method 1086 * @param comparator to use for comparisons 1087 * @param items to compare 1088 * @return T at middle position 1089 * @throws NullPointerException if items or comparator is {@code null} 1090 * @throws IllegalArgumentException if items is empty or contains {@code null} values 1091 * @since 3.0.1 1092 */ 1093 @SafeVarargs 1094 public static <T> T median(final Comparator<T> comparator, final T... items) { 1095 Validate.notEmpty(items, "null/empty items"); 1096 Validate.noNullElements(items); 1097 Objects.requireNonNull(comparator, "comparator"); 1098 final TreeSet<T> treeSet = new TreeSet<>(comparator); 1099 Collections.addAll(treeSet, items); 1100 return (T) treeSet.toArray()[(treeSet.size() - 1) / 2]; 1101 } 1102 1103 /** 1104 * Find the "best guess" middle value among comparables. If there is an even 1105 * number of total values, the lower of the two middle values will be returned. 1106 * @param <T> type of values processed by this method 1107 * @param items to compare 1108 * @return T at middle position 1109 * @throws NullPointerException if items is {@code null} 1110 * @throws IllegalArgumentException if items is empty or contains {@code null} values 1111 * @since 3.0.1 1112 */ 1113 @SafeVarargs 1114 public static <T extends Comparable<? super T>> T median(final T... items) { 1115 Validate.notEmpty(items); 1116 Validate.noNullElements(items); 1117 final TreeSet<T> sort = new TreeSet<>(); 1118 Collections.addAll(sort, items); 1119 return (T) sort.toArray()[(sort.size() - 1) / 2]; 1120 } 1121 1122 /** 1123 * Null safe comparison of Comparables. 1124 * <p>TODO Move to ComparableUtils.</p> 1125 * 1126 * @param <T> type of the values processed by this method 1127 * @param values the set of comparable values, may be null 1128 * @return 1129 * <ul> 1130 * <li>If any objects are non-null and unequal, the lesser object. 1131 * <li>If all objects are non-null and equal, the first. 1132 * <li>If any of the comparables are null, the lesser of the non-null objects. 1133 * <li>If all the comparables are null, null is returned. 1134 * </ul> 1135 */ 1136 @SafeVarargs 1137 public static <T extends Comparable<? super T>> T min(final T... values) { 1138 T result = null; 1139 if (values != null) { 1140 for (final T value : values) { 1141 if (compare(value, result, true) < 0) { 1142 result = value; 1143 } 1144 } 1145 } 1146 return result; 1147 } 1148 1149 /** 1150 * Find the most frequently occurring item. 1151 * 1152 * @param <T> type of values processed by this method 1153 * @param items to check 1154 * @return most populous T, {@code null} if non-unique or no items supplied 1155 * @since 3.0.1 1156 */ 1157 @SafeVarargs 1158 public static <T> T mode(final T... items) { 1159 if (ArrayUtils.isNotEmpty(items)) { 1160 final HashMap<T, MutableInt> occurrences = new HashMap<>(items.length); 1161 for (final T t : items) { 1162 final MutableInt count = occurrences.get(t); 1163 if (count == null) { 1164 occurrences.put(t, new MutableInt(1)); 1165 } else { 1166 count.increment(); 1167 } 1168 } 1169 T result = null; 1170 int max = 0; 1171 for (final Map.Entry<T, MutableInt> e : occurrences.entrySet()) { 1172 final int cmp = e.getValue().intValue(); 1173 if (cmp == max) { 1174 result = null; 1175 } else if (cmp > max) { 1176 max = cmp; 1177 result = e.getKey(); 1178 } 1179 } 1180 return result; 1181 } 1182 return null; 1183 } 1184 1185 /** 1186 * Compares two objects for inequality, where either one or both 1187 * objects may be {@code null}. 1188 * 1189 * <pre> 1190 * ObjectUtils.notEqual(null, null) = false 1191 * ObjectUtils.notEqual(null, "") = true 1192 * ObjectUtils.notEqual("", null) = true 1193 * ObjectUtils.notEqual("", "") = false 1194 * ObjectUtils.notEqual(Boolean.TRUE, null) = true 1195 * ObjectUtils.notEqual(Boolean.TRUE, "true") = true 1196 * ObjectUtils.notEqual(Boolean.TRUE, Boolean.TRUE) = false 1197 * ObjectUtils.notEqual(Boolean.TRUE, Boolean.FALSE) = true 1198 * </pre> 1199 * 1200 * @param object1 the first object, may be {@code null} 1201 * @param object2 the second object, may be {@code null} 1202 * @return {@code false} if the values of both objects are the same 1203 */ 1204 public static boolean notEqual(final Object object1, final Object object2) { 1205 return !Objects.equals(object1, object2); 1206 } 1207 1208 /** 1209 * Checks that the specified object reference is not {@code null} or empty per {@link #isEmpty(Object)}. Use this 1210 * method for validation, for example: 1211 * 1212 * <blockquote> 1213 * 1214 * <pre> 1215 * public Foo(Bar bar) { 1216 * this.bar = Objects.requireNonEmpty(bar); 1217 * } 1218 * </pre> 1219 * 1220 * </blockquote> 1221 * 1222 * @param <T> the type of the reference. 1223 * @param obj the object reference to check for nullity. 1224 * @return {@code obj} if not {@code null}. 1225 * @throws NullPointerException if {@code obj} is {@code null}. 1226 * @throws IllegalArgumentException if {@code obj} is empty per {@link #isEmpty(Object)}. 1227 * @see #isEmpty(Object) 1228 * @since 3.12.0 1229 */ 1230 public static <T> T requireNonEmpty(final T obj) { 1231 return requireNonEmpty(obj, "object"); 1232 } 1233 1234 /** 1235 * Checks that the specified object reference is not {@code null} or empty per {@link #isEmpty(Object)}. Use this 1236 * method for validation, for example: 1237 * 1238 * <blockquote> 1239 * 1240 * <pre> 1241 * public Foo(Bar bar) { 1242 * this.bar = Objects.requireNonEmpty(bar, "bar"); 1243 * } 1244 * </pre> 1245 * 1246 * </blockquote> 1247 * 1248 * @param <T> the type of the reference. 1249 * @param obj the object reference to check for nullity. 1250 * @param message the exception message. 1251 * @return {@code obj} if not {@code null}. 1252 * @throws NullPointerException if {@code obj} is {@code null}. 1253 * @throws IllegalArgumentException if {@code obj} is empty per {@link #isEmpty(Object)}. 1254 * @see #isEmpty(Object) 1255 * @since 3.12.0 1256 */ 1257 public static <T> T requireNonEmpty(final T obj, final String message) { 1258 // check for null first to give the most precise exception. 1259 Objects.requireNonNull(obj, message); 1260 if (isEmpty(obj)) { 1261 throw new IllegalArgumentException(message); 1262 } 1263 return obj; 1264 } 1265 1266 /** 1267 * Gets the {@code toString} of an {@link Object} returning 1268 * an empty string ("") if {@code null} input. 1269 * 1270 * <pre> 1271 * ObjectUtils.toString(null) = "" 1272 * ObjectUtils.toString("") = "" 1273 * ObjectUtils.toString("bat") = "bat" 1274 * ObjectUtils.toString(Boolean.TRUE) = "true" 1275 * </pre> 1276 * 1277 * @see Objects#toString(Object) 1278 * @see Objects#toString(Object, String) 1279 * @see StringUtils#defaultString(String) 1280 * @see String#valueOf(Object) 1281 * @param obj the Object to {@code toString}, may be null 1282 * @return the passed in Object's toString, or {@code ""} if {@code null} input 1283 * @since 2.0 1284 * @deprecated this method has been replaced by {@code java.util.Objects.toString(Object)} in Java 7 and will be 1285 * removed in future releases. Note however that said method will return "null" for null references, while this 1286 * method returns an empty String. To preserve behavior use {@code java.util.Objects.toString(myObject, "")} 1287 */ 1288 @Deprecated 1289 public static String toString(final Object obj) { 1290 return Objects.toString(obj, StringUtils.EMPTY); 1291 } 1292 1293 /** 1294 * Gets the {@code toString} of an {@link Object} returning 1295 * a specified text if {@code null} input. 1296 * 1297 * <pre> 1298 * ObjectUtils.toString(null, null) = null 1299 * ObjectUtils.toString(null, "null") = "null" 1300 * ObjectUtils.toString("", "null") = "" 1301 * ObjectUtils.toString("bat", "null") = "bat" 1302 * ObjectUtils.toString(Boolean.TRUE, "null") = "true" 1303 * </pre> 1304 * 1305 * @see Objects#toString(Object) 1306 * @see Objects#toString(Object, String) 1307 * @see StringUtils#defaultString(String,String) 1308 * @see String#valueOf(Object) 1309 * @param obj the Object to {@code toString}, may be null 1310 * @param nullStr the String to return if {@code null} input, may be null 1311 * @return the passed in Object's toString, or {@code nullStr} if {@code null} input 1312 * @since 2.0 1313 * @deprecated this method has been replaced by {@code java.util.Objects.toString(Object, String)} in Java 7 and 1314 * will be removed in future releases. 1315 */ 1316 @Deprecated 1317 public static String toString(final Object obj, final String nullStr) { 1318 return Objects.toString(obj, nullStr); 1319 } 1320 1321 /** 1322 * Gets the {@code toString} of an {@link Supplier}'s {@link Supplier#get()} returning 1323 * a specified text if {@code null} input. 1324 * 1325 * <pre> 1326 * ObjectUtils.toString(() -> obj, () -> expensive()) 1327 * </pre> 1328 * <pre> 1329 * ObjectUtils.toString(() -> null, () -> expensive()) = result of expensive() 1330 * ObjectUtils.toString(() -> null, () -> expensive()) = result of expensive() 1331 * ObjectUtils.toString(() -> "", () -> expensive()) = "" 1332 * ObjectUtils.toString(() -> "bat", () -> expensive()) = "bat" 1333 * ObjectUtils.toString(() -> Boolean.TRUE, () -> expensive()) = "true" 1334 * </pre> 1335 * 1336 * @param obj the Object to {@code toString}, may be null 1337 * @param supplier the Supplier of String used on {@code null} input, may be null 1338 * @return the passed in Object's toString, or {@code nullStr} if {@code null} input 1339 * @since 3.14.0 1340 */ 1341 public static String toString(final Supplier<Object> obj, final Supplier<String> supplier) { 1342 return obj == null ? Suppliers.get(supplier) : toString(obj.get(), supplier); 1343 } 1344 1345 /** 1346 * Gets the {@code toString} of an {@link Object} returning 1347 * a specified text if {@code null} input. 1348 * 1349 * <pre> 1350 * ObjectUtils.toString(obj, () -> expensive()) 1351 * </pre> 1352 * <pre> 1353 * ObjectUtils.toString(null, () -> expensive()) = result of expensive() 1354 * ObjectUtils.toString(null, () -> expensive()) = result of expensive() 1355 * ObjectUtils.toString("", () -> expensive()) = "" 1356 * ObjectUtils.toString("bat", () -> expensive()) = "bat" 1357 * ObjectUtils.toString(Boolean.TRUE, () -> expensive()) = "true" 1358 * </pre> 1359 * 1360 * @param <T> the obj type (used to provide better source compatibility in 3.14.0). 1361 * @param obj the Object to {@code toString}, may be null 1362 * @param supplier the Supplier of String used on {@code null} input, may be null 1363 * @return the passed in Object's toString, or {@code nullStr} if {@code null} input 1364 * @since 3.11 1365 */ 1366 public static <T> String toString(final T obj, final Supplier<String> supplier) { 1367 return obj == null ? Suppliers.get(supplier) : obj.toString(); 1368 } 1369 1370 /** 1371 * Calls {@link Object#wait(long, int)} for the given Duration. 1372 * 1373 * @param obj The receiver of the wait call. 1374 * @param duration How long to wait. 1375 * @throws IllegalArgumentException if the timeout duration is negative. 1376 * @throws IllegalMonitorStateException if the current thread is not the owner of the {@code obj}'s monitor. 1377 * @throws InterruptedException if any thread interrupted the current thread before or while the current thread was 1378 * waiting for a notification. The <em>interrupted status</em> of the current thread is cleared when this 1379 * exception is thrown. 1380 * @see Object#wait(long, int) 1381 * @since 3.12.0 1382 */ 1383 public static void wait(final Object obj, final Duration duration) throws InterruptedException { 1384 DurationUtils.accept(obj::wait, DurationUtils.zeroIfNull(duration)); 1385 } 1386 1387 /** 1388 * {@link ObjectUtils} instances should NOT be constructed in 1389 * standard programming. Instead, the static methods on the class should 1390 * be used, such as {@code ObjectUtils.defaultIfNull("a","b");}. 1391 * 1392 * <p>This constructor is public to permit tools that require a JavaBean 1393 * instance to operate.</p> 1394 * 1395 * @deprecated TODO Make private in 4.0. 1396 */ 1397 @Deprecated 1398 public ObjectUtils() { 1399 // empty 1400 } 1401 1402}