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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  package org.apache.commons.lang3.builder;
18  
19  import java.lang.reflect.AccessibleObject;
20  import java.lang.reflect.Field;
21  import java.lang.reflect.Modifier;
22  import java.util.ArrayList;
23  import java.util.Collection;
24  import java.util.HashSet;
25  import java.util.List;
26  import java.util.Set;
27  
28  import org.apache.commons.lang3.ArrayUtils;
29  import org.apache.commons.lang3.ClassUtils;
30  import org.apache.commons.lang3.tuple.Pair;
31  
32  /**
33   * Assists in implementing {@link Object#equals(Object)} methods.
34   *
35   * <p> This class provides methods to build a good equals method for any
36   * class. It follows rules laid out in
37   * <a href="https://www.oracle.com/java/technologies/effectivejava.html">Effective Java</a>
38   * , by Joshua Bloch. In particular the rule for comparing {@code doubles},
39   * {@code floats}, and arrays can be tricky. Also, making sure that
40   * {@code equals()} and {@code hashCode()} are consistent can be
41   * difficult.</p>
42   *
43   * <p>Two Objects that compare as equals must generate the same hash code,
44   * but two Objects with the same hash code do not have to be equal.</p>
45   *
46   * <p>All relevant fields should be included in the calculation of equals.
47   * Derived fields may be ignored. In particular, any field used in
48   * generating a hash code must be used in the equals method, and vice
49   * versa.</p>
50   *
51   * <p>Typical use for the code is as follows:</p>
52   * <pre>
53   * public boolean equals(Object obj) {
54   *   if (obj == null) { return false; }
55   *   if (obj == this) { return true; }
56   *   if (obj.getClass() != getClass()) {
57   *     return false;
58   *   }
59   *   MyClass rhs = (MyClass) obj;
60   *   return new EqualsBuilder()
61   *                 .appendSuper(super.equals(obj))
62   *                 .append(field1, rhs.field1)
63   *                 .append(field2, rhs.field2)
64   *                 .append(field3, rhs.field3)
65   *                 .isEquals();
66   *  }
67   * </pre>
68   *
69   * <p> Alternatively, there is a method that uses reflection to determine
70   * the fields to test. Because these fields are usually private, the method,
71   * {@code reflectionEquals}, uses {@code AccessibleObject.setAccessible} to
72   * change the visibility of the fields. This will fail under a security
73   * manager, unless the appropriate permissions are set up correctly. It is
74   * also slower than testing explicitly.  Non-primitive fields are compared using
75   * {@code equals()}.</p>
76   *
77   * <p> A typical invocation for this method would look like:</p>
78   * <pre>
79   * public boolean equals(Object obj) {
80   *   return EqualsBuilder.reflectionEquals(this, obj);
81   * }
82   * </pre>
83   *
84   * <p>The {@link EqualsExclude} annotation can be used to exclude fields from being
85   * used by the {@code reflectionEquals} methods.</p>
86   *
87   * @since 1.0
88   */
89  public class EqualsBuilder implements Builder<Boolean> {
90  
91      /**
92       * A registry of objects used by reflection methods to detect cyclical object references and avoid infinite loops.
93       *
94       * @since 3.0
95       */
96      private static final ThreadLocal<Set<Pair<IDKey, IDKey>>> REGISTRY = new ThreadLocal<>();
97  
98      /*
99       * NOTE: we cannot store the actual objects in a HashSet, as that would use the very hashCode()
100      * we are in the process of calculating.
101      *
102      * So we generate a one-to-one mapping from the original object to a new object.
103      *
104      * Now HashSet uses equals() to determine if two elements with the same hash code really
105      * are equal, so we also need to ensure that the replacement objects are only equal
106      * if the original objects are identical.
107      *
108      * The original implementation (2.4 and before) used the System.identityHashCode()
109      * method - however this is not guaranteed to generate unique ids (e.g. LANG-459)
110      *
111      * We now use the IDKey helper class (adapted from org.apache.axis.utils.IDKey)
112      * to disambiguate the duplicate ids.
113      */
114 
115     /**
116      * Returns the registry of object pairs being traversed by the reflection
117      * methods in the current thread.
118      *
119      * @return Set the registry of objects being traversed
120      * @since 3.0
121      */
122     static Set<Pair<IDKey, IDKey>> getRegistry() {
123         return REGISTRY.get();
124     }
125 
126     /**
127      * Converters value pair into a register pair.
128      *
129      * @param lhs {@code this} object
130      * @param rhs the other object
131      *
132      * @return the pair
133      */
134     static Pair<IDKey, IDKey> getRegisterPair(final Object lhs, final Object rhs) {
135         final IDKey left = new IDKey(lhs);
136         final IDKey right = new IDKey(rhs);
137         return Pair.of(left, right);
138     }
139 
140     /**
141      * Returns {@code true} if the registry contains the given object pair.
142      * Used by the reflection methods to avoid infinite loops.
143      * Objects might be swapped therefore a check is needed if the object pair
144      * is registered in given or swapped order.
145      *
146      * @param lhs {@code this} object to lookup in registry
147      * @param rhs the other object to lookup on registry
148      * @return boolean {@code true} if the registry contains the given object.
149      * @since 3.0
150      */
151     static boolean isRegistered(final Object lhs, final Object rhs) {
152         final Set<Pair<IDKey, IDKey>> registry = getRegistry();
153         final Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
154         final Pair<IDKey, IDKey> swappedPair = Pair.of(pair.getRight(), pair.getLeft());
155 
156         return registry != null
157                 && (registry.contains(pair) || registry.contains(swappedPair));
158     }
159 
160     /**
161      * Registers the given object pair.
162      * Used by the reflection methods to avoid infinite loops.
163      *
164      * @param lhs {@code this} object to register
165      * @param rhs the other object to register
166      */
167     private static void register(final Object lhs, final Object rhs) {
168         Set<Pair<IDKey, IDKey>> registry = getRegistry();
169         if (registry == null) {
170             registry = new HashSet<>();
171             REGISTRY.set(registry);
172         }
173         final Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
174         registry.add(pair);
175     }
176 
177     /**
178      * Unregisters the given object pair.
179      *
180      * <p>
181      * Used by the reflection methods to avoid infinite loops.
182      *
183      * @param lhs {@code this} object to unregister
184      * @param rhs the other object to unregister
185      * @since 3.0
186      */
187     private static void unregister(final Object lhs, final Object rhs) {
188         final Set<Pair<IDKey, IDKey>> registry = getRegistry();
189         if (registry != null) {
190             registry.remove(getRegisterPair(lhs, rhs));
191             if (registry.isEmpty()) {
192                 REGISTRY.remove();
193             }
194         }
195     }
196 
197     /**
198      * If the fields tested are equals.
199      * The default value is {@code true}.
200      */
201     private boolean isEquals = true;
202 
203     private boolean testTransients;
204     private boolean testRecursive;
205     private List<Class<?>> bypassReflectionClasses;
206     private Class<?> reflectUpToClass;
207     private String[] excludeFields;
208 
209     /**
210      * Constructor for EqualsBuilder.
211      *
212      * <p>Starts off assuming that equals is {@code true}.</p>
213      * @see Object#equals(Object)
214      */
215     public EqualsBuilder() {
216         // set up default classes to bypass reflection for
217         bypassReflectionClasses = new ArrayList<>(1);
218         bypassReflectionClasses.add(String.class); //hashCode field being lazy but not transient
219     }
220 
221     /**
222      * Set whether to include transient fields when reflectively comparing objects.
223      * @param testTransients whether to test transient fields
224      * @return this
225      * @since 3.6
226      */
227     public EqualsBuilder setTestTransients(final boolean testTransients) {
228         this.testTransients = testTransients;
229         return this;
230     }
231 
232     /**
233      * Set whether to test fields recursively, instead of using their equals method, when reflectively comparing objects.
234      * String objects, which cache a hash value, are automatically excluded from recursive testing.
235      * You may specify other exceptions by calling {@link #setBypassReflectionClasses(List)}.
236      * @param testRecursive whether to do a recursive test
237      * @return this
238      * @see #setBypassReflectionClasses(List)
239      * @since 3.6
240      */
241     public EqualsBuilder setTestRecursive(final boolean testRecursive) {
242         this.testRecursive = testRecursive;
243         return this;
244     }
245 
246     /**
247      * Set {@link Class}es whose instances should be compared by calling their {@code equals}
248      * although being in recursive mode. So the fields of theses classes will not be compared recursively by reflection.
249      *
250      * <p>Here you should name classes having non-transient fields which are cache fields being set lazily.<br>
251      * Prominent example being {@link String} class with its hash code cache field. Due to the importance
252      * of the {@link String} class, it is included in the default bypasses classes. Usually, if you use
253      * your own set of classes here, remember to include {@link String} class, too.</p>
254      * @param bypassReflectionClasses  classes to bypass reflection test
255      * @return this
256      * @see #setTestRecursive(boolean)
257      * @since 3.8
258      */
259     public EqualsBuilder setBypassReflectionClasses(final List<Class<?>> bypassReflectionClasses) {
260         this.bypassReflectionClasses = bypassReflectionClasses;
261         return this;
262     }
263 
264     /**
265      * Set the superclass to reflect up to at reflective tests.
266      * @param reflectUpToClass the super class to reflect up to
267      * @return this
268      * @since 3.6
269      */
270     public EqualsBuilder setReflectUpToClass(final Class<?> reflectUpToClass) {
271         this.reflectUpToClass = reflectUpToClass;
272         return this;
273     }
274 
275     /**
276      * Set field names to be excluded by reflection tests.
277      * @param excludeFields the fields to exclude
278      * @return this
279      * @since 3.6
280      */
281     public EqualsBuilder setExcludeFields(final String... excludeFields) {
282         this.excludeFields = excludeFields;
283         return this;
284     }
285 
286 
287     /**
288      * This method uses reflection to determine if the two {@link Object}s
289      * are equal.
290      *
291      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
292      * fields. This means that it will throw a security exception if run under
293      * a security manager, if the permissions are not set up correctly. It is also
294      * not as efficient as testing explicitly. Non-primitive fields are compared using
295      * {@code equals()}.</p>
296      *
297      * <p>Transient members will be not be tested, as they are likely derived
298      * fields, and not part of the value of the Object.</p>
299      *
300      * <p>Static fields will not be tested. Superclass fields will be included.</p>
301      *
302      * @param lhs  {@code this} object
303      * @param rhs  the other object
304      * @param excludeFields  Collection of String field names to exclude from testing
305      * @return {@code true} if the two Objects have tested equals.
306      *
307      * @see EqualsExclude
308      */
309     public static boolean reflectionEquals(final Object lhs, final Object rhs, final Collection<String> excludeFields) {
310         return reflectionEquals(lhs, rhs, ReflectionToStringBuilder.toNoNullStringArray(excludeFields));
311     }
312 
313     /**
314      * This method uses reflection to determine if the two {@link Object}s
315      * are equal.
316      *
317      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
318      * fields. This means that it will throw a security exception if run under
319      * a security manager, if the permissions are not set up correctly. It is also
320      * not as efficient as testing explicitly. Non-primitive fields are compared using
321      * {@code equals()}.</p>
322      *
323      * <p>Transient members will be not be tested, as they are likely derived
324      * fields, and not part of the value of the Object.</p>
325      *
326      * <p>Static fields will not be tested. Superclass fields will be included.</p>
327      *
328      * @param lhs  {@code this} object
329      * @param rhs  the other object
330      * @param excludeFields  array of field names to exclude from testing
331      * @return {@code true} if the two Objects have tested equals.
332      *
333      * @see EqualsExclude
334      */
335     public static boolean reflectionEquals(final Object lhs, final Object rhs, final String... excludeFields) {
336         return reflectionEquals(lhs, rhs, false, null, excludeFields);
337     }
338 
339     /**
340      * This method uses reflection to determine if the two {@link Object}s
341      * are equal.
342      *
343      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
344      * fields. This means that it will throw a security exception if run under
345      * a security manager, if the permissions are not set up correctly. It is also
346      * not as efficient as testing explicitly. Non-primitive fields are compared using
347      * {@code equals()}.</p>
348      *
349      * <p>If the TestTransients parameter is set to {@code true}, transient
350      * members will be tested, otherwise they are ignored, as they are likely
351      * derived fields, and not part of the value of the {@link Object}.</p>
352      *
353      * <p>Static fields will not be tested. Superclass fields will be included.</p>
354      *
355      * @param lhs  {@code this} object
356      * @param rhs  the other object
357      * @param testTransients  whether to include transient fields
358      * @return {@code true} if the two Objects have tested equals.
359      *
360      * @see EqualsExclude
361      */
362     public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients) {
363         return reflectionEquals(lhs, rhs, testTransients, null);
364     }
365 
366     /**
367      * This method uses reflection to determine if the two {@link Object}s
368      * are equal.
369      *
370      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
371      * fields. This means that it will throw a security exception if run under
372      * a security manager, if the permissions are not set up correctly. It is also
373      * not as efficient as testing explicitly. Non-primitive fields are compared using
374      * {@code equals()}.</p>
375      *
376      * <p>If the testTransients parameter is set to {@code true}, transient
377      * members will be tested, otherwise they are ignored, as they are likely
378      * derived fields, and not part of the value of the {@link Object}.</p>
379      *
380      * <p>Static fields will not be included. Superclass fields will be appended
381      * up to and including the specified superclass. A null superclass is treated
382      * as java.lang.Object.</p>
383      *
384      * @param lhs  {@code this} object
385      * @param rhs  the other object
386      * @param testTransients  whether to include transient fields
387      * @param reflectUpToClass  the superclass to reflect up to (inclusive),
388      *  may be {@code null}
389      * @param excludeFields  array of field names to exclude from testing
390      * @return {@code true} if the two Objects have tested equals.
391      *
392      * @see EqualsExclude
393      * @since 2.0
394      */
395     public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients, final Class<?> reflectUpToClass,
396             final String... excludeFields) {
397         return reflectionEquals(lhs, rhs, testTransients, reflectUpToClass, false, excludeFields);
398     }
399 
400     /**
401      * This method uses reflection to determine if the two {@link Object}s
402      * are equal.
403      *
404      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
405      * fields. This means that it will throw a security exception if run under
406      * a security manager, if the permissions are not set up correctly. It is also
407      * not as efficient as testing explicitly. Non-primitive fields are compared using
408      * {@code equals()}.</p>
409      *
410      * <p>If the testTransients parameter is set to {@code true}, transient
411      * members will be tested, otherwise they are ignored, as they are likely
412      * derived fields, and not part of the value of the {@link Object}.</p>
413      *
414      * <p>Static fields will not be included. Superclass fields will be appended
415      * up to and including the specified superclass. A null superclass is treated
416      * as java.lang.Object.</p>
417      *
418      * <p>If the testRecursive parameter is set to {@code true}, non primitive
419      * (and non primitive wrapper) field types will be compared by
420      * {@link EqualsBuilder} recursively instead of invoking their
421      * {@code equals()} method. Leading to a deep reflection equals test.
422      *
423      * @param lhs  {@code this} object
424      * @param rhs  the other object
425      * @param testTransients  whether to include transient fields
426      * @param reflectUpToClass  the superclass to reflect up to (inclusive),
427      *  may be {@code null}
428      * @param testRecursive  whether to call reflection equals on non-primitive
429      *  fields recursively.
430      * @param excludeFields  array of field names to exclude from testing
431      * @return {@code true} if the two Objects have tested equals.
432      *
433      * @see EqualsExclude
434      * @since 3.6
435      */
436     public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients, final Class<?> reflectUpToClass,
437             final boolean testRecursive, final String... excludeFields) {
438         if (lhs == rhs) {
439             return true;
440         }
441         if (lhs == null || rhs == null) {
442             return false;
443         }
444         return new EqualsBuilder()
445                     .setExcludeFields(excludeFields)
446                     .setReflectUpToClass(reflectUpToClass)
447                     .setTestTransients(testTransients)
448                     .setTestRecursive(testRecursive)
449                     .reflectionAppend(lhs, rhs)
450                     .isEquals();
451     }
452 
453     /**
454      * Tests if two {@code objects} by using reflection.
455      *
456      * <p>It uses {@code AccessibleObject.setAccessible} to gain access to private
457      * fields. This means that it will throw a security exception if run under
458      * a security manager, if the permissions are not set up correctly. It is also
459      * not as efficient as testing explicitly. Non-primitive fields are compared using
460      * {@code equals()}.</p>
461      *
462      * <p>If the testTransients field is set to {@code true}, transient
463      * members will be tested, otherwise they are ignored, as they are likely
464      * derived fields, and not part of the value of the {@link Object}.</p>
465      *
466      * <p>Static fields will not be included. Superclass fields will be appended
467      * up to and including the specified superclass in field {@code reflectUpToClass}.
468      * A null superclass is treated as java.lang.Object.</p>
469      *
470      * <p>Field names listed in field {@code excludeFields} will be ignored.</p>
471      *
472      * <p>If either class of the compared objects is contained in
473      * {@code bypassReflectionClasses}, both objects are compared by calling
474      * the equals method of the left-hand object with the right-hand object as an argument.</p>
475      *
476      * @param lhs  the left-hand object
477      * @param rhs  the right-hand object
478      * @return this
479      */
480     public EqualsBuilder reflectionAppend(final Object lhs, final Object rhs) {
481         if (!isEquals) {
482             return this;
483         }
484         if (lhs == rhs) {
485             return this;
486         }
487         if (lhs == null || rhs == null) {
488             isEquals = false;
489             return this;
490         }
491 
492         // Find the leaf class since there may be transients in the leaf
493         // class or in classes between the leaf and root.
494         // If we are not testing transients or a subclass has no ivars,
495         // then a subclass can test equals to a superclass.
496         final Class<?> lhsClass = lhs.getClass();
497         final Class<?> rhsClass = rhs.getClass();
498         Class<?> testClass;
499         if (lhsClass.isInstance(rhs)) {
500             testClass = lhsClass;
501             if (!rhsClass.isInstance(lhs)) {
502                 // rhsClass is a subclass of lhsClass
503                 testClass = rhsClass;
504             }
505         } else if (rhsClass.isInstance(lhs)) {
506             testClass = rhsClass;
507             if (!lhsClass.isInstance(rhs)) {
508                 // lhsClass is a subclass of rhsClass
509                 testClass = lhsClass;
510             }
511         } else {
512             // The two classes are not related.
513             isEquals = false;
514             return this;
515         }
516 
517         try {
518             if (testClass.isArray()) {
519                 append(lhs, rhs);
520             } else //If either class is being excluded, call normal object equals method on lhsClass.
521             if (bypassReflectionClasses != null
522                     && (bypassReflectionClasses.contains(lhsClass) || bypassReflectionClasses.contains(rhsClass))) {
523                 isEquals = lhs.equals(rhs);
524             } else {
525                 reflectionAppend(lhs, rhs, testClass);
526                 while (testClass.getSuperclass() != null && testClass != reflectUpToClass) {
527                     testClass = testClass.getSuperclass();
528                     reflectionAppend(lhs, rhs, testClass);
529                 }
530             }
531         } catch (final IllegalArgumentException e) {
532             // In this case, we tried to test a subclass vs. a superclass and
533             // the subclass has ivars or the ivars are transient and
534             // we are testing transients.
535             // If a subclass has ivars that we are trying to test them, we get an
536             // exception and we know that the objects are not equal.
537             isEquals = false;
538         }
539         return this;
540     }
541 
542     /**
543      * Appends the fields and values defined by the given object of the
544      * given Class.
545      *
546      * @param lhs  the left-hand object
547      * @param rhs  the right-hand object
548      * @param clazz  the class to append details of
549      */
550     private void reflectionAppend(
551         final Object lhs,
552         final Object rhs,
553         final Class<?> clazz) {
554 
555         if (isRegistered(lhs, rhs)) {
556             return;
557         }
558 
559         try {
560             register(lhs, rhs);
561             final Field[] fields = clazz.getDeclaredFields();
562             AccessibleObject.setAccessible(fields, true);
563             for (int i = 0; i < fields.length && isEquals; i++) {
564                 final Field field = fields[i];
565                 if (!ArrayUtils.contains(excludeFields, field.getName())
566                     && !field.getName().contains("$")
567                     && (testTransients || !Modifier.isTransient(field.getModifiers()))
568                     && !Modifier.isStatic(field.getModifiers())
569                     && !field.isAnnotationPresent(EqualsExclude.class)) {
570                     append(Reflection.getUnchecked(field, lhs), Reflection.getUnchecked(field, rhs));
571                 }
572             }
573         } finally {
574             unregister(lhs, rhs);
575         }
576     }
577 
578     /**
579      * Adds the result of {@code super.equals()} to this builder.
580      *
581      * @param superEquals  the result of calling {@code super.equals()}
582      * @return this
583      * @since 2.0
584      */
585     public EqualsBuilder appendSuper(final boolean superEquals) {
586         if (!isEquals) {
587             return this;
588         }
589         isEquals = superEquals;
590         return this;
591     }
592 
593     /**
594      * Test if two {@link Object}s are equal using either
595      * #{@link #reflectionAppend(Object, Object)}, if object are non
596      * primitives (or wrapper of primitives) or if field {@code testRecursive}
597      * is set to {@code false}. Otherwise, using their
598      * {@code equals} method.
599      *
600      * @param lhs  the left-hand object
601      * @param rhs  the right-hand object
602      * @return this
603      */
604     public EqualsBuilder append(final Object lhs, final Object rhs) {
605         if (!isEquals) {
606             return this;
607         }
608         if (lhs == rhs) {
609             return this;
610         }
611         if (lhs == null || rhs == null) {
612             this.setEquals(false);
613             return this;
614         }
615         final Class<?> lhsClass = lhs.getClass();
616         if (lhsClass.isArray()) {
617             // factor out array case in order to keep method small enough
618             // to be inlined
619             appendArray(lhs, rhs);
620         } else // The simple case, not an array, just test the element
621         if (testRecursive && !ClassUtils.isPrimitiveOrWrapper(lhsClass)) {
622             reflectionAppend(lhs, rhs);
623         } else {
624             isEquals = lhs.equals(rhs);
625         }
626         return this;
627     }
628 
629     /**
630      * Test if an {@link Object} is equal to an array.
631      *
632      * @param lhs  the left-hand object, an array
633      * @param rhs  the right-hand object
634      */
635     private void appendArray(final Object lhs, final Object rhs) {
636         // First we compare different dimensions, for example: a boolean[][] to a boolean[]
637         // then we 'Switch' on type of array, to dispatch to the correct handler
638         // This handles multidimensional arrays of the same depth
639         if (lhs.getClass() != rhs.getClass()) {
640             this.setEquals(false);
641         } else if (lhs instanceof long[]) {
642             append((long[]) lhs, (long[]) rhs);
643         } else if (lhs instanceof int[]) {
644             append((int[]) lhs, (int[]) rhs);
645         } else if (lhs instanceof short[]) {
646             append((short[]) lhs, (short[]) rhs);
647         } else if (lhs instanceof char[]) {
648             append((char[]) lhs, (char[]) rhs);
649         } else if (lhs instanceof byte[]) {
650             append((byte[]) lhs, (byte[]) rhs);
651         } else if (lhs instanceof double[]) {
652             append((double[]) lhs, (double[]) rhs);
653         } else if (lhs instanceof float[]) {
654             append((float[]) lhs, (float[]) rhs);
655         } else if (lhs instanceof boolean[]) {
656             append((boolean[]) lhs, (boolean[]) rhs);
657         } else {
658             // Not an array of primitives
659             append((Object[]) lhs, (Object[]) rhs);
660         }
661     }
662 
663     /**
664      * Test if two {@code long} s are equal.
665      *
666      * @param lhs
667      *                  the left-hand {@code long}
668      * @param rhs
669      *                  the right-hand {@code long}
670      * @return this
671      */
672     public EqualsBuilder append(final long lhs, final long rhs) {
673         if (!isEquals) {
674             return this;
675         }
676         isEquals = lhs == rhs;
677         return this;
678     }
679 
680     /**
681      * Test if two {@code int}s are equal.
682      *
683      * @param lhs  the left-hand {@code int}
684      * @param rhs  the right-hand {@code int}
685      * @return this
686      */
687     public EqualsBuilder append(final int lhs, final int rhs) {
688         if (!isEquals) {
689             return this;
690         }
691         isEquals = lhs == rhs;
692         return this;
693     }
694 
695     /**
696      * Test if two {@code short}s are equal.
697      *
698      * @param lhs  the left-hand {@code short}
699      * @param rhs  the right-hand {@code short}
700      * @return this
701      */
702     public EqualsBuilder append(final short lhs, final short rhs) {
703         if (!isEquals) {
704             return this;
705         }
706         isEquals = lhs == rhs;
707         return this;
708     }
709 
710     /**
711      * Test if two {@code char}s are equal.
712      *
713      * @param lhs  the left-hand {@code char}
714      * @param rhs  the right-hand {@code char}
715      * @return this
716      */
717     public EqualsBuilder append(final char lhs, final char rhs) {
718         if (!isEquals) {
719             return this;
720         }
721         isEquals = lhs == rhs;
722         return this;
723     }
724 
725     /**
726      * Test if two {@code byte}s are equal.
727      *
728      * @param lhs  the left-hand {@code byte}
729      * @param rhs  the right-hand {@code byte}
730      * @return this
731      */
732     public EqualsBuilder append(final byte lhs, final byte rhs) {
733         if (!isEquals) {
734             return this;
735         }
736         isEquals = lhs == rhs;
737         return this;
738     }
739 
740     /**
741      * Test if two {@code double}s are equal by testing that the
742      * pattern of bits returned by {@code doubleToLong} are equal.
743      *
744      * <p>This handles NaNs, Infinities, and {@code -0.0}.</p>
745      *
746      * <p>It is compatible with the hash code generated by
747      * {@link HashCodeBuilder}.</p>
748      *
749      * @param lhs  the left-hand {@code double}
750      * @param rhs  the right-hand {@code double}
751      * @return this
752      */
753     public EqualsBuilder append(final double lhs, final double rhs) {
754         if (!isEquals) {
755             return this;
756         }
757         return append(Double.doubleToLongBits(lhs), Double.doubleToLongBits(rhs));
758     }
759 
760     /**
761      * Test if two {@code float}s are equal by testing that the
762      * pattern of bits returned by doubleToLong are equal.
763      *
764      * <p>This handles NaNs, Infinities, and {@code -0.0}.</p>
765      *
766      * <p>It is compatible with the hash code generated by
767      * {@link HashCodeBuilder}.</p>
768      *
769      * @param lhs  the left-hand {@code float}
770      * @param rhs  the right-hand {@code float}
771      * @return this
772      */
773     public EqualsBuilder append(final float lhs, final float rhs) {
774         if (!isEquals) {
775             return this;
776         }
777         return append(Float.floatToIntBits(lhs), Float.floatToIntBits(rhs));
778     }
779 
780     /**
781      * Test if two {@code booleans}s are equal.
782      *
783      * @param lhs  the left-hand {@code boolean}
784      * @param rhs  the right-hand {@code boolean}
785      * @return this
786       */
787     public EqualsBuilder append(final boolean lhs, final boolean rhs) {
788         if (!isEquals) {
789             return this;
790         }
791         isEquals = lhs == rhs;
792         return this;
793     }
794 
795     /**
796      * Performs a deep comparison of two {@link Object} arrays.
797      *
798      * <p>This also will be called for the top level of
799      * multi-dimensional, ragged, and multi-typed arrays.</p>
800      *
801      * <p>Note that this method does not compare the type of the arrays; it only
802      * compares the contents.</p>
803      *
804      * @param lhs  the left-hand {@code Object[]}
805      * @param rhs  the right-hand {@code Object[]}
806      * @return this
807      */
808     public EqualsBuilder append(final Object[] lhs, final Object[] rhs) {
809         if (!isEquals) {
810             return this;
811         }
812         if (lhs == rhs) {
813             return this;
814         }
815         if (lhs == null || rhs == null) {
816             this.setEquals(false);
817             return this;
818         }
819         if (lhs.length != rhs.length) {
820             this.setEquals(false);
821             return this;
822         }
823         for (int i = 0; i < lhs.length && isEquals; ++i) {
824             append(lhs[i], rhs[i]);
825         }
826         return this;
827     }
828 
829     /**
830      * Deep comparison of array of {@code long}. Length and all
831      * values are compared.
832      *
833      * <p>The method {@link #append(long, long)} is used.</p>
834      *
835      * @param lhs  the left-hand {@code long[]}
836      * @param rhs  the right-hand {@code long[]}
837      * @return this
838      */
839     public EqualsBuilder append(final long[] lhs, final long[] rhs) {
840         if (!isEquals) {
841             return this;
842         }
843         if (lhs == rhs) {
844             return this;
845         }
846         if (lhs == null || rhs == null) {
847             this.setEquals(false);
848             return this;
849         }
850         if (lhs.length != rhs.length) {
851             this.setEquals(false);
852             return this;
853         }
854         for (int i = 0; i < lhs.length && isEquals; ++i) {
855             append(lhs[i], rhs[i]);
856         }
857         return this;
858     }
859 
860     /**
861      * Deep comparison of array of {@code int}. Length and all
862      * values are compared.
863      *
864      * <p>The method {@link #append(int, int)} is used.</p>
865      *
866      * @param lhs  the left-hand {@code int[]}
867      * @param rhs  the right-hand {@code int[]}
868      * @return this
869      */
870     public EqualsBuilder append(final int[] lhs, final int[] rhs) {
871         if (!isEquals) {
872             return this;
873         }
874         if (lhs == rhs) {
875             return this;
876         }
877         if (lhs == null || rhs == null) {
878             this.setEquals(false);
879             return this;
880         }
881         if (lhs.length != rhs.length) {
882             this.setEquals(false);
883             return this;
884         }
885         for (int i = 0; i < lhs.length && isEquals; ++i) {
886             append(lhs[i], rhs[i]);
887         }
888         return this;
889     }
890 
891     /**
892      * Deep comparison of array of {@code short}. Length and all
893      * values are compared.
894      *
895      * <p>The method {@link #append(short, short)} is used.</p>
896      *
897      * @param lhs  the left-hand {@code short[]}
898      * @param rhs  the right-hand {@code short[]}
899      * @return this
900      */
901     public EqualsBuilder append(final short[] lhs, final short[] rhs) {
902         if (!isEquals) {
903             return this;
904         }
905         if (lhs == rhs) {
906             return this;
907         }
908         if (lhs == null || rhs == null) {
909             this.setEquals(false);
910             return this;
911         }
912         if (lhs.length != rhs.length) {
913             this.setEquals(false);
914             return this;
915         }
916         for (int i = 0; i < lhs.length && isEquals; ++i) {
917             append(lhs[i], rhs[i]);
918         }
919         return this;
920     }
921 
922     /**
923      * Deep comparison of array of {@code char}. Length and all
924      * values are compared.
925      *
926      * <p>The method {@link #append(char, char)} is used.</p>
927      *
928      * @param lhs  the left-hand {@code char[]}
929      * @param rhs  the right-hand {@code char[]}
930      * @return this
931      */
932     public EqualsBuilder append(final char[] lhs, final char[] rhs) {
933         if (!isEquals) {
934             return this;
935         }
936         if (lhs == rhs) {
937             return this;
938         }
939         if (lhs == null || rhs == null) {
940             this.setEquals(false);
941             return this;
942         }
943         if (lhs.length != rhs.length) {
944             this.setEquals(false);
945             return this;
946         }
947         for (int i = 0; i < lhs.length && isEquals; ++i) {
948             append(lhs[i], rhs[i]);
949         }
950         return this;
951     }
952 
953     /**
954      * Deep comparison of array of {@code byte}. Length and all
955      * values are compared.
956      *
957      * <p>The method {@link #append(byte, byte)} is used.</p>
958      *
959      * @param lhs  the left-hand {@code byte[]}
960      * @param rhs  the right-hand {@code byte[]}
961      * @return this
962      */
963     public EqualsBuilder append(final byte[] lhs, final byte[] rhs) {
964         if (!isEquals) {
965             return this;
966         }
967         if (lhs == rhs) {
968             return this;
969         }
970         if (lhs == null || rhs == null) {
971             this.setEquals(false);
972             return this;
973         }
974         if (lhs.length != rhs.length) {
975             this.setEquals(false);
976             return this;
977         }
978         for (int i = 0; i < lhs.length && isEquals; ++i) {
979             append(lhs[i], rhs[i]);
980         }
981         return this;
982     }
983 
984     /**
985      * Deep comparison of array of {@code double}. Length and all
986      * values are compared.
987      *
988      * <p>The method {@link #append(double, double)} is used.</p>
989      *
990      * @param lhs  the left-hand {@code double[]}
991      * @param rhs  the right-hand {@code double[]}
992      * @return this
993      */
994     public EqualsBuilder append(final double[] lhs, final double[] rhs) {
995         if (!isEquals) {
996             return this;
997         }
998         if (lhs == rhs) {
999             return this;
1000         }
1001         if (lhs == null || rhs == null) {
1002             this.setEquals(false);
1003             return this;
1004         }
1005         if (lhs.length != rhs.length) {
1006             this.setEquals(false);
1007             return this;
1008         }
1009         for (int i = 0; i < lhs.length && isEquals; ++i) {
1010             append(lhs[i], rhs[i]);
1011         }
1012         return this;
1013     }
1014 
1015     /**
1016      * Deep comparison of array of {@code float}. Length and all
1017      * values are compared.
1018      *
1019      * <p>The method {@link #append(float, float)} is used.</p>
1020      *
1021      * @param lhs  the left-hand {@code float[]}
1022      * @param rhs  the right-hand {@code float[]}
1023      * @return this
1024      */
1025     public EqualsBuilder append(final float[] lhs, final float[] rhs) {
1026         if (!isEquals) {
1027             return this;
1028         }
1029         if (lhs == rhs) {
1030             return this;
1031         }
1032         if (lhs == null || rhs == null) {
1033             this.setEquals(false);
1034             return this;
1035         }
1036         if (lhs.length != rhs.length) {
1037             this.setEquals(false);
1038             return this;
1039         }
1040         for (int i = 0; i < lhs.length && isEquals; ++i) {
1041             append(lhs[i], rhs[i]);
1042         }
1043         return this;
1044     }
1045 
1046     /**
1047      * Deep comparison of array of {@code boolean}. Length and all
1048      * values are compared.
1049      *
1050      * <p>The method {@link #append(boolean, boolean)} is used.</p>
1051      *
1052      * @param lhs  the left-hand {@code boolean[]}
1053      * @param rhs  the right-hand {@code boolean[]}
1054      * @return this
1055      */
1056     public EqualsBuilder append(final boolean[] lhs, final boolean[] rhs) {
1057         if (!isEquals) {
1058             return this;
1059         }
1060         if (lhs == rhs) {
1061             return this;
1062         }
1063         if (lhs == null || rhs == null) {
1064             this.setEquals(false);
1065             return this;
1066         }
1067         if (lhs.length != rhs.length) {
1068             this.setEquals(false);
1069             return this;
1070         }
1071         for (int i = 0; i < lhs.length && isEquals; ++i) {
1072             append(lhs[i], rhs[i]);
1073         }
1074         return this;
1075     }
1076 
1077     /**
1078      * Returns {@code true} if the fields that have been checked
1079      * are all equal.
1080      *
1081      * @return boolean
1082      */
1083     public boolean isEquals() {
1084         return this.isEquals;
1085     }
1086 
1087     /**
1088      * Returns {@code true} if the fields that have been checked
1089      * are all equal.
1090      *
1091      * @return {@code true} if all of the fields that have been checked
1092      *         are equal, {@code false} otherwise.
1093      *
1094      * @since 3.0
1095      */
1096     @Override
1097     public Boolean build() {
1098         return Boolean.valueOf(isEquals());
1099     }
1100 
1101     /**
1102      * Sets the {@code isEquals} value.
1103      *
1104      * @param isEquals The value to set.
1105      * @since 2.1
1106      */
1107     protected void setEquals(final boolean isEquals) {
1108         this.isEquals = isEquals;
1109     }
1110 
1111     /**
1112      * Reset the EqualsBuilder so you can use the same object again
1113      * @since 2.5
1114      */
1115     public void reset() {
1116         this.isEquals = true;
1117     }
1118 }