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.builder;
018
019import java.lang.reflect.AccessibleObject;
020import java.lang.reflect.Field;
021import java.lang.reflect.Modifier;
022import java.util.Collection;
023import java.util.HashSet;
024import java.util.Set;
025
026import org.apache.commons.lang3.ArrayUtils;
027import org.apache.commons.lang3.ClassUtils;
028import org.apache.commons.lang3.tuple.Pair;
029
030/**
031 * <p>Assists in implementing {@link Object#equals(Object)} methods.</p>
032 *
033 * <p> This class provides methods to build a good equals method for any
034 * class. It follows rules laid out in
035 * <a href="http://www.oracle.com/technetwork/java/effectivejava-136174.html">Effective Java</a>
036 * , by Joshua Bloch. In particular the rule for comparing <code>doubles</code>,
037 * <code>floats</code>, and arrays can be tricky. Also, making sure that
038 * <code>equals()</code> and <code>hashCode()</code> are consistent can be
039 * difficult.</p>
040 *
041 * <p>Two Objects that compare as equals must generate the same hash code,
042 * but two Objects with the same hash code do not have to be equal.</p>
043 *
044 * <p>All relevant fields should be included in the calculation of equals.
045 * Derived fields may be ignored. In particular, any field used in
046 * generating a hash code must be used in the equals method, and vice
047 * versa.</p>
048 *
049 * <p>Typical use for the code is as follows:</p>
050 * <pre>
051 * public boolean equals(Object obj) {
052 *   if (obj == null) { return false; }
053 *   if (obj == this) { return true; }
054 *   if (obj.getClass() != getClass()) {
055 *     return false;
056 *   }
057 *   MyClass rhs = (MyClass) obj;
058 *   return new EqualsBuilder()
059 *                 .appendSuper(super.equals(obj))
060 *                 .append(field1, rhs.field1)
061 *                 .append(field2, rhs.field2)
062 *                 .append(field3, rhs.field3)
063 *                 .isEquals();
064 *  }
065 * </pre>
066 *
067 * <p> Alternatively, there is a method that uses reflection to determine
068 * the fields to test. Because these fields are usually private, the method,
069 * <code>reflectionEquals</code>, uses <code>AccessibleObject.setAccessible</code> to
070 * change the visibility of the fields. This will fail under a security
071 * manager, unless the appropriate permissions are set up correctly. It is
072 * also slower than testing explicitly.  Non-primitive fields are compared using
073 * <code>equals()</code>.</p>
074 *
075 * <p> A typical invocation for this method would look like:</p>
076 * <pre>
077 * public boolean equals(Object obj) {
078 *   return EqualsBuilder.reflectionEquals(this, obj);
079 * }
080 * </pre>
081 *
082 * <p>The {@link EqualsExclude} annotation can be used to exclude fields from being
083 * used by the <code>reflectionEquals</code> methods.</p>
084 *
085 * @since 1.0
086 */
087public class EqualsBuilder implements Builder<Boolean> {
088
089    /**
090     * <p>
091     * A registry of objects used by reflection methods to detect cyclical object references and avoid infinite loops.
092     * </p>
093     *
094     * @since 3.0
095     */
096    private static final ThreadLocal<Set<Pair<IDKey, IDKey>>> REGISTRY = new ThreadLocal<>();
097
098    /*
099     * 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     * <p>
117     * Returns the registry of object pairs being traversed by the reflection
118     * methods in the current thread.
119     * </p>
120     *
121     * @return Set the registry of objects being traversed
122     * @since 3.0
123     */
124    static Set<Pair<IDKey, IDKey>> getRegistry() {
125        return REGISTRY.get();
126    }
127
128    /**
129     * <p>
130     * Converters value pair into a register pair.
131     * </p>
132     *
133     * @param lhs <code>this</code> object
134     * @param rhs the other object
135     *
136     * @return the pair
137     */
138    static Pair<IDKey, IDKey> getRegisterPair(final Object lhs, final Object rhs) {
139        final IDKey left = new IDKey(lhs);
140        final IDKey right = new IDKey(rhs);
141        return Pair.of(left, right);
142    }
143
144    /**
145     * <p>
146     * Returns <code>true</code> if the registry contains the given object pair.
147     * Used by the reflection methods to avoid infinite loops.
148     * Objects might be swapped therefore a check is needed if the object pair
149     * is registered in given or swapped order.
150     * </p>
151     *
152     * @param lhs <code>this</code> object to lookup in registry
153     * @param rhs the other object to lookup on registry
154     * @return boolean <code>true</code> if the registry contains the given object.
155     * @since 3.0
156     */
157    static boolean isRegistered(final Object lhs, final Object rhs) {
158        final Set<Pair<IDKey, IDKey>> registry = getRegistry();
159        final Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
160        final Pair<IDKey, IDKey> swappedPair = Pair.of(pair.getRight(), pair.getLeft());
161
162        return registry != null
163                && (registry.contains(pair) || registry.contains(swappedPair));
164    }
165
166    /**
167     * <p>
168     * Registers the given object pair.
169     * Used by the reflection methods to avoid infinite loops.
170     * </p>
171     *
172     * @param lhs <code>this</code> object to register
173     * @param rhs the other object to register
174     */
175    private static void register(final Object lhs, final Object rhs) {
176        Set<Pair<IDKey, IDKey>> registry = getRegistry();
177        if (registry == null) {
178            registry = new HashSet<>();
179            REGISTRY.set(registry);
180        }
181        final Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
182        registry.add(pair);
183    }
184
185    /**
186     * <p>
187     * Unregisters the given object pair.
188     * </p>
189     *
190     * <p>
191     * Used by the reflection methods to avoid infinite loops.
192     *
193     * @param lhs <code>this</code> object to unregister
194     * @param rhs the other object to unregister
195     * @since 3.0
196     */
197    private static void unregister(final Object lhs, final Object rhs) {
198        final Set<Pair<IDKey, IDKey>> registry = getRegistry();
199        if (registry != null) {
200            final Pair<IDKey, IDKey> pair = getRegisterPair(lhs, rhs);
201            registry.remove(pair);
202            if (registry.isEmpty()) {
203                REGISTRY.remove();
204            }
205        }
206    }
207
208    /**
209     * If the fields tested are equals.
210     * The default value is <code>true</code>.
211     */
212    private boolean isEquals = true;
213
214    private boolean testTransients = false;
215    private boolean testRecursive = false;
216    private Class<?> reflectUpToClass = null;
217    private String[] excludeFields = null;
218
219    /**
220     * <p>Constructor for EqualsBuilder.</p>
221     *
222     * <p>Starts off assuming that equals is <code>true</code>.</p>
223     * @see Object#equals(Object)
224     */
225    public EqualsBuilder() {
226        // do nothing for now.
227    }
228
229    //-------------------------------------------------------------------------
230
231    /**
232     * Set whether to include transient fields when reflectively comparing objects.
233     * @param testTransients whether to test transient fields
234     * @return EqualsBuilder - used to chain calls.
235     * @since 3.6
236     */
237    public EqualsBuilder setTestTransients(final boolean testTransients) {
238        this.testTransients = testTransients;
239        return this;
240    }
241
242    /**
243     * Set whether to include transient fields when reflectively comparing objects.
244     * @param testRecursive  whether to do a recursive test
245     * @return EqualsBuilder - used to chain calls.
246     * @since 3.6
247     */
248    public EqualsBuilder setTestRecursive(final boolean testRecursive) {
249        this.testRecursive = testRecursive;
250        return this;
251    }
252
253    /**
254     * Set the superclass to reflect up to at reflective tests.
255     * @param reflectUpToClass the super class to reflect up to
256     * @return EqualsBuilder - used to chain calls.
257     * @since 3.6
258     */
259    public EqualsBuilder setReflectUpToClass(final Class<?> reflectUpToClass) {
260        this.reflectUpToClass = reflectUpToClass;
261        return this;
262    }
263
264    /**
265     * Set field names to be excluded by reflection tests.
266     * @param excludeFields the fields to exclude
267     * @return EqualsBuilder - used to chain calls.
268     * @since 3.6
269     */
270    public EqualsBuilder setExcludeFields(final String... excludeFields) {
271        this.excludeFields = excludeFields;
272        return this;
273    }
274
275
276    /**
277     * <p>This method uses reflection to determine if the two <code>Object</code>s
278     * are equal.</p>
279     *
280     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
281     * fields. This means that it will throw a security exception if run under
282     * a security manager, if the permissions are not set up correctly. It is also
283     * not as efficient as testing explicitly. Non-primitive fields are compared using
284     * <code>equals()</code>.</p>
285     *
286     * <p>Transient members will be not be tested, as they are likely derived
287     * fields, and not part of the value of the Object.</p>
288     *
289     * <p>Static fields will not be tested. Superclass fields will be included.</p>
290     *
291     * @param lhs  <code>this</code> object
292     * @param rhs  the other object
293     * @param excludeFields  Collection of String field names to exclude from testing
294     * @return <code>true</code> if the two Objects have tested equals.
295     *
296     * @see EqualsExclude
297     */
298    public static boolean reflectionEquals(final Object lhs, final Object rhs, final Collection<String> excludeFields) {
299        return reflectionEquals(lhs, rhs, ReflectionToStringBuilder.toNoNullStringArray(excludeFields));
300    }
301
302    /**
303     * <p>This method uses reflection to determine if the two <code>Object</code>s
304     * are equal.</p>
305     *
306     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
307     * fields. This means that it will throw a security exception if run under
308     * a security manager, if the permissions are not set up correctly. It is also
309     * not as efficient as testing explicitly. Non-primitive fields are compared using
310     * <code>equals()</code>.</p>
311     *
312     * <p>Transient members will be not be tested, as they are likely derived
313     * fields, and not part of the value of the Object.</p>
314     *
315     * <p>Static fields will not be tested. Superclass fields will be included.</p>
316     *
317     * @param lhs  <code>this</code> object
318     * @param rhs  the other object
319     * @param excludeFields  array of field names to exclude from testing
320     * @return <code>true</code> if the two Objects have tested equals.
321     *
322     * @see EqualsExclude
323     */
324    public static boolean reflectionEquals(final Object lhs, final Object rhs, final String... excludeFields) {
325        return reflectionEquals(lhs, rhs, false, null, excludeFields);
326    }
327
328    /**
329     * <p>This method uses reflection to determine if the two <code>Object</code>s
330     * are equal.</p>
331     *
332     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
333     * fields. This means that it will throw a security exception if run under
334     * a security manager, if the permissions are not set up correctly. It is also
335     * not as efficient as testing explicitly. Non-primitive fields are compared using
336     * <code>equals()</code>.</p>
337     *
338     * <p>If the TestTransients parameter is set to <code>true</code>, transient
339     * members will be tested, otherwise they are ignored, as they are likely
340     * derived fields, and not part of the value of the <code>Object</code>.</p>
341     *
342     * <p>Static fields will not be tested. Superclass fields will be included.</p>
343     *
344     * @param lhs  <code>this</code> object
345     * @param rhs  the other object
346     * @param testTransients  whether to include transient fields
347     * @return <code>true</code> if the two Objects have tested equals.
348     *
349     * @see EqualsExclude
350     */
351    public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients) {
352        return reflectionEquals(lhs, rhs, testTransients, null);
353    }
354
355    /**
356     * <p>This method uses reflection to determine if the two <code>Object</code>s
357     * are equal.</p>
358     *
359     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
360     * fields. This means that it will throw a security exception if run under
361     * a security manager, if the permissions are not set up correctly. It is also
362     * not as efficient as testing explicitly. Non-primitive fields are compared using
363     * <code>equals()</code>.</p>
364     *
365     * <p>If the testTransients parameter is set to <code>true</code>, transient
366     * members will be tested, otherwise they are ignored, as they are likely
367     * derived fields, and not part of the value of the <code>Object</code>.</p>
368     *
369     * <p>Static fields will not be included. Superclass fields will be appended
370     * up to and including the specified superclass. A null superclass is treated
371     * as java.lang.Object.</p>
372     *
373     * @param lhs  <code>this</code> object
374     * @param rhs  the other object
375     * @param testTransients  whether to include transient fields
376     * @param reflectUpToClass  the superclass to reflect up to (inclusive),
377     *  may be <code>null</code>
378     * @param excludeFields  array of field names to exclude from testing
379     * @return <code>true</code> if the two Objects have tested equals.
380     *
381     * @see EqualsExclude
382     * @since 2.0
383     */
384    public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients, final Class<?> reflectUpToClass,
385            final String... excludeFields) {
386        return reflectionEquals(lhs, rhs, testTransients, reflectUpToClass, false, excludeFields);
387    }
388
389    /**
390     * <p>This method uses reflection to determine if the two <code>Object</code>s
391     * are equal.</p>
392     *
393     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
394     * fields. This means that it will throw a security exception if run under
395     * a security manager, if the permissions are not set up correctly. It is also
396     * not as efficient as testing explicitly. Non-primitive fields are compared using
397     * <code>equals()</code>.</p>
398     *
399     * <p>If the testTransients parameter is set to <code>true</code>, transient
400     * members will be tested, otherwise they are ignored, as they are likely
401     * derived fields, and not part of the value of the <code>Object</code>.</p>
402     *
403     * <p>Static fields will not be included. Superclass fields will be appended
404     * up to and including the specified superclass. A null superclass is treated
405     * as java.lang.Object.</p>
406     *
407     * <p>If the testRecursive parameter is set to <code>true</code>, non primitive
408     * (and non primitive wrapper) field types will be compared by
409     * <code>EqualsBuilder</code> recursively instead of invoking their
410     * <code>equals()</code> method. Leading to a deep reflection equals test.
411     *
412     * @param lhs  <code>this</code> object
413     * @param rhs  the other object
414     * @param testTransients  whether to include transient fields
415     * @param reflectUpToClass  the superclass to reflect up to (inclusive),
416     *  may be <code>null</code>
417     * @param testRecursive  whether to call reflection equals on non primitive
418     *  fields recursively.
419     * @param excludeFields  array of field names to exclude from testing
420     * @return <code>true</code> if the two Objects have tested equals.
421     *
422     * @see EqualsExclude
423     * @since 3.6
424     */
425    public static boolean reflectionEquals(final Object lhs, final Object rhs, final boolean testTransients, final Class<?> reflectUpToClass,
426            final boolean testRecursive, final String... excludeFields) {
427        if (lhs == rhs) {
428            return true;
429        }
430        if (lhs == null || rhs == null) {
431            return false;
432        }
433        return new EqualsBuilder()
434                    .setExcludeFields(excludeFields)
435                    .setReflectUpToClass(reflectUpToClass)
436                    .setTestTransients(testTransients)
437                    .setTestRecursive(testRecursive)
438                    .reflectionAppend(lhs, rhs)
439                    .isEquals();
440    }
441
442    /**
443     * <p>Tests if two <code>objects</code> by using reflection.</p>
444     *
445     * <p>It uses <code>AccessibleObject.setAccessible</code> to gain access to private
446     * fields. This means that it will throw a security exception if run under
447     * a security manager, if the permissions are not set up correctly. It is also
448     * not as efficient as testing explicitly. Non-primitive fields are compared using
449     * <code>equals()</code>.</p>
450     *
451     * <p>If the testTransients field is set to <code>true</code>, transient
452     * members will be tested, otherwise they are ignored, as they are likely
453     * derived fields, and not part of the value of the <code>Object</code>.</p>
454     *
455     * <p>Static fields will not be included. Superclass fields will be appended
456     * up to and including the specified superclass in field <code>reflectUpToClass</code>.
457     * A null superclass is treated as java.lang.Object.</p>
458     *
459     * <p>Field names listed in field <code>excludeFields</code> will be ignored.</p>
460     *
461     * @param lhs  the left hand object
462     * @param rhs  the left hand object
463     * @return EqualsBuilder - used to chain calls.
464     */
465    public EqualsBuilder reflectionAppend(final Object lhs, final Object rhs) {
466        if (!isEquals) {
467            return this;
468        }
469        if (lhs == rhs) {
470            return this;
471        }
472        if (lhs == null || rhs == null) {
473            isEquals = false;
474            return this;
475        }
476
477        // Find the leaf class since there may be transients in the leaf
478        // class or in classes between the leaf and root.
479        // If we are not testing transients or a subclass has no ivars,
480        // then a subclass can test equals to a superclass.
481        final Class<?> lhsClass = lhs.getClass();
482        final Class<?> rhsClass = rhs.getClass();
483        Class<?> testClass;
484        if (lhsClass.isInstance(rhs)) {
485            testClass = lhsClass;
486            if (!rhsClass.isInstance(lhs)) {
487                // rhsClass is a subclass of lhsClass
488                testClass = rhsClass;
489            }
490        } else if (rhsClass.isInstance(lhs)) {
491            testClass = rhsClass;
492            if (!lhsClass.isInstance(rhs)) {
493                // lhsClass is a subclass of rhsClass
494                testClass = lhsClass;
495            }
496        } else {
497            // The two classes are not related.
498            isEquals = false;
499            return this;
500        }
501
502        try {
503            if (testClass.isArray()) {
504                append(lhs, rhs);
505            } else {
506                reflectionAppend(lhs, rhs, testClass);
507                while (testClass.getSuperclass() != null && testClass != reflectUpToClass) {
508                    testClass = testClass.getSuperclass();
509                    reflectionAppend(lhs, rhs, testClass);
510                }
511            }
512        } catch (final IllegalArgumentException e) {
513            // In this case, we tried to test a subclass vs. a superclass and
514            // the subclass has ivars or the ivars are transient and
515            // we are testing transients.
516            // If a subclass has ivars that we are trying to test them, we get an
517            // exception and we know that the objects are not equal.
518            isEquals = false;
519            return this;
520        }
521        return this;
522    }
523
524    /**
525     * <p>Appends the fields and values defined by the given object of the
526     * given Class.</p>
527     *
528     * @param lhs  the left hand object
529     * @param rhs  the right hand object
530     * @param clazz  the class to append details of
531     */
532    private void reflectionAppend(
533        final Object lhs,
534        final Object rhs,
535        final Class<?> clazz) {
536
537        if (isRegistered(lhs, rhs)) {
538            return;
539        }
540
541        try {
542            register(lhs, rhs);
543            final Field[] fields = clazz.getDeclaredFields();
544            AccessibleObject.setAccessible(fields, true);
545            for (int i = 0; i < fields.length && isEquals; i++) {
546                final Field f = fields[i];
547                if (!ArrayUtils.contains(excludeFields, f.getName())
548                    && !f.getName().contains("$")
549                    && (testTransients || !Modifier.isTransient(f.getModifiers()))
550                    && !Modifier.isStatic(f.getModifiers())
551                    && !f.isAnnotationPresent(EqualsExclude.class)) {
552                    try {
553                        append(f.get(lhs), f.get(rhs));
554                    } catch (final IllegalAccessException e) {
555                        //this can't happen. Would get a Security exception instead
556                        //throw a runtime exception in case the impossible happens.
557                        throw new InternalError("Unexpected IllegalAccessException");
558                    }
559                }
560            }
561        } finally {
562            unregister(lhs, rhs);
563        }
564    }
565
566    //-------------------------------------------------------------------------
567
568    /**
569     * <p>Adds the result of <code>super.equals()</code> to this builder.</p>
570     *
571     * @param superEquals  the result of calling <code>super.equals()</code>
572     * @return EqualsBuilder - used to chain calls.
573     * @since 2.0
574     */
575    public EqualsBuilder appendSuper(final boolean superEquals) {
576        if (!isEquals) {
577            return this;
578        }
579        isEquals = superEquals;
580        return this;
581    }
582
583    //-------------------------------------------------------------------------
584
585    /**
586     * <p>Test if two <code>Object</code>s are equal using either
587     * #{@link #reflectionAppend(Object, Object)}, if object are non
588     * primitives (or wrapper of primitives) or if field <code>testRecursive</code>
589     * is set to <code>false</code>. Otherwise, using their
590     * <code>equals</code> method.</p>
591     *
592     * @param lhs  the left hand object
593     * @param rhs  the right hand object
594     * @return EqualsBuilder - used to chain calls.
595     */
596    public EqualsBuilder append(final Object lhs, final Object rhs) {
597        if (!isEquals) {
598            return this;
599        }
600        if (lhs == rhs) {
601            return this;
602        }
603        if (lhs == null || rhs == null) {
604            this.setEquals(false);
605            return this;
606        }
607        final Class<?> lhsClass = lhs.getClass();
608        if (!lhsClass.isArray()) {
609            // The simple case, not an array, just test the element
610            if (testRecursive && !ClassUtils.isPrimitiveOrWrapper(lhsClass)) {
611                reflectionAppend(lhs, rhs);
612            } else {
613                isEquals = lhs.equals(rhs);
614            }
615        } else {
616            // factor out array case in order to keep method small enough
617            // to be inlined
618            appendArray(lhs, rhs);
619        }
620        return this;
621    }
622
623    /**
624     * <p>Test if an <code>Object</code> is equal to an array.</p>
625     *
626     * @param lhs  the left hand object, an array
627     * @param rhs  the right hand object
628     */
629    private void appendArray(final Object lhs, final Object rhs) {
630        // First we compare different dimensions, for example: a boolean[][] to a boolean[]
631        // then we 'Switch' on type of array, to dispatch to the correct handler
632        // This handles multi dimensional arrays of the same depth
633        if (lhs.getClass() != rhs.getClass()) {
634            this.setEquals(false);
635        } else if (lhs instanceof long[]) {
636            append((long[]) lhs, (long[]) rhs);
637        } else if (lhs instanceof int[]) {
638            append((int[]) lhs, (int[]) rhs);
639        } else if (lhs instanceof short[]) {
640            append((short[]) lhs, (short[]) rhs);
641        } else if (lhs instanceof char[]) {
642            append((char[]) lhs, (char[]) rhs);
643        } else if (lhs instanceof byte[]) {
644            append((byte[]) lhs, (byte[]) rhs);
645        } else if (lhs instanceof double[]) {
646            append((double[]) lhs, (double[]) rhs);
647        } else if (lhs instanceof float[]) {
648            append((float[]) lhs, (float[]) rhs);
649        } else if (lhs instanceof boolean[]) {
650            append((boolean[]) lhs, (boolean[]) rhs);
651        } else {
652            // Not an array of primitives
653            append((Object[]) lhs, (Object[]) rhs);
654        }
655    }
656
657    /**
658     * <p>
659     * Test if two <code>long</code> s are equal.
660     * </p>
661     *
662     * @param lhs
663     *                  the left hand <code>long</code>
664     * @param rhs
665     *                  the right hand <code>long</code>
666     * @return EqualsBuilder - used to chain calls.
667     */
668    public EqualsBuilder append(final long lhs, final long rhs) {
669        if (!isEquals) {
670            return this;
671        }
672        isEquals = lhs == rhs;
673        return this;
674    }
675
676    /**
677     * <p>Test if two <code>int</code>s are equal.</p>
678     *
679     * @param lhs  the left hand <code>int</code>
680     * @param rhs  the right hand <code>int</code>
681     * @return EqualsBuilder - used to chain calls.
682     */
683    public EqualsBuilder append(final int lhs, final int rhs) {
684        if (!isEquals) {
685            return this;
686        }
687        isEquals = lhs == rhs;
688        return this;
689    }
690
691    /**
692     * <p>Test if two <code>short</code>s are equal.</p>
693     *
694     * @param lhs  the left hand <code>short</code>
695     * @param rhs  the right hand <code>short</code>
696     * @return EqualsBuilder - used to chain calls.
697     */
698    public EqualsBuilder append(final short lhs, final short rhs) {
699        if (!isEquals) {
700            return this;
701        }
702        isEquals = lhs == rhs;
703        return this;
704    }
705
706    /**
707     * <p>Test if two <code>char</code>s are equal.</p>
708     *
709     * @param lhs  the left hand <code>char</code>
710     * @param rhs  the right hand <code>char</code>
711     * @return EqualsBuilder - used to chain calls.
712     */
713    public EqualsBuilder append(final char lhs, final char rhs) {
714        if (!isEquals) {
715            return this;
716        }
717        isEquals = lhs == rhs;
718        return this;
719    }
720
721    /**
722     * <p>Test if two <code>byte</code>s are equal.</p>
723     *
724     * @param lhs  the left hand <code>byte</code>
725     * @param rhs  the right hand <code>byte</code>
726     * @return EqualsBuilder - used to chain calls.
727     */
728    public EqualsBuilder append(final byte lhs, final byte rhs) {
729        if (!isEquals) {
730            return this;
731        }
732        isEquals = lhs == rhs;
733        return this;
734    }
735
736    /**
737     * <p>Test if two <code>double</code>s are equal by testing that the
738     * pattern of bits returned by <code>doubleToLong</code> are equal.</p>
739     *
740     * <p>This handles NaNs, Infinities, and <code>-0.0</code>.</p>
741     *
742     * <p>It is compatible with the hash code generated by
743     * <code>HashCodeBuilder</code>.</p>
744     *
745     * @param lhs  the left hand <code>double</code>
746     * @param rhs  the right hand <code>double</code>
747     * @return EqualsBuilder - used to chain calls.
748     */
749    public EqualsBuilder append(final double lhs, final double rhs) {
750        if (!isEquals) {
751            return this;
752        }
753        return append(Double.doubleToLongBits(lhs), Double.doubleToLongBits(rhs));
754    }
755
756    /**
757     * <p>Test if two <code>float</code>s are equal byt testing that the
758     * pattern of bits returned by doubleToLong are equal.</p>
759     *
760     * <p>This handles NaNs, Infinities, and <code>-0.0</code>.</p>
761     *
762     * <p>It is compatible with the hash code generated by
763     * <code>HashCodeBuilder</code>.</p>
764     *
765     * @param lhs  the left hand <code>float</code>
766     * @param rhs  the right hand <code>float</code>
767     * @return EqualsBuilder - used to chain calls.
768     */
769    public EqualsBuilder append(final float lhs, final float rhs) {
770        if (!isEquals) {
771            return this;
772        }
773        return append(Float.floatToIntBits(lhs), Float.floatToIntBits(rhs));
774    }
775
776    /**
777     * <p>Test if two <code>booleans</code>s are equal.</p>
778     *
779     * @param lhs  the left hand <code>boolean</code>
780     * @param rhs  the right hand <code>boolean</code>
781     * @return EqualsBuilder - used to chain calls.
782      */
783    public EqualsBuilder append(final boolean lhs, final boolean rhs) {
784        if (!isEquals) {
785            return this;
786        }
787        isEquals = lhs == rhs;
788        return this;
789    }
790
791    /**
792     * <p>Performs a deep comparison of two <code>Object</code> arrays.</p>
793     *
794     * <p>This also will be called for the top level of
795     * multi-dimensional, ragged, and multi-typed arrays.</p>
796     *
797     * <p>Note that this method does not compare the type of the arrays; it only
798     * compares the contents.</p>
799     *
800     * @param lhs  the left hand <code>Object[]</code>
801     * @param rhs  the right hand <code>Object[]</code>
802     * @return EqualsBuilder - used to chain calls.
803     */
804    public EqualsBuilder append(final Object[] lhs, final Object[] rhs) {
805        if (!isEquals) {
806            return this;
807        }
808        if (lhs == rhs) {
809            return this;
810        }
811        if (lhs == null || rhs == null) {
812            this.setEquals(false);
813            return this;
814        }
815        if (lhs.length != rhs.length) {
816            this.setEquals(false);
817            return this;
818        }
819        for (int i = 0; i < lhs.length && isEquals; ++i) {
820            append(lhs[i], rhs[i]);
821        }
822        return this;
823    }
824
825    /**
826     * <p>Deep comparison of array of <code>long</code>. Length and all
827     * values are compared.</p>
828     *
829     * <p>The method {@link #append(long, long)} is used.</p>
830     *
831     * @param lhs  the left hand <code>long[]</code>
832     * @param rhs  the right hand <code>long[]</code>
833     * @return EqualsBuilder - used to chain calls.
834     */
835    public EqualsBuilder append(final long[] lhs, final long[] rhs) {
836        if (!isEquals) {
837            return this;
838        }
839        if (lhs == rhs) {
840            return this;
841        }
842        if (lhs == null || rhs == null) {
843            this.setEquals(false);
844            return this;
845        }
846        if (lhs.length != rhs.length) {
847            this.setEquals(false);
848            return this;
849        }
850        for (int i = 0; i < lhs.length && isEquals; ++i) {
851            append(lhs[i], rhs[i]);
852        }
853        return this;
854    }
855
856    /**
857     * <p>Deep comparison of array of <code>int</code>. Length and all
858     * values are compared.</p>
859     *
860     * <p>The method {@link #append(int, int)} is used.</p>
861     *
862     * @param lhs  the left hand <code>int[]</code>
863     * @param rhs  the right hand <code>int[]</code>
864     * @return EqualsBuilder - used to chain calls.
865     */
866    public EqualsBuilder append(final int[] lhs, final int[] rhs) {
867        if (!isEquals) {
868            return this;
869        }
870        if (lhs == rhs) {
871            return this;
872        }
873        if (lhs == null || rhs == null) {
874            this.setEquals(false);
875            return this;
876        }
877        if (lhs.length != rhs.length) {
878            this.setEquals(false);
879            return this;
880        }
881        for (int i = 0; i < lhs.length && isEquals; ++i) {
882            append(lhs[i], rhs[i]);
883        }
884        return this;
885    }
886
887    /**
888     * <p>Deep comparison of array of <code>short</code>. Length and all
889     * values are compared.</p>
890     *
891     * <p>The method {@link #append(short, short)} is used.</p>
892     *
893     * @param lhs  the left hand <code>short[]</code>
894     * @param rhs  the right hand <code>short[]</code>
895     * @return EqualsBuilder - used to chain calls.
896     */
897    public EqualsBuilder append(final short[] lhs, final short[] rhs) {
898        if (!isEquals) {
899            return this;
900        }
901        if (lhs == rhs) {
902            return this;
903        }
904        if (lhs == null || rhs == null) {
905            this.setEquals(false);
906            return this;
907        }
908        if (lhs.length != rhs.length) {
909            this.setEquals(false);
910            return this;
911        }
912        for (int i = 0; i < lhs.length && isEquals; ++i) {
913            append(lhs[i], rhs[i]);
914        }
915        return this;
916    }
917
918    /**
919     * <p>Deep comparison of array of <code>char</code>. Length and all
920     * values are compared.</p>
921     *
922     * <p>The method {@link #append(char, char)} is used.</p>
923     *
924     * @param lhs  the left hand <code>char[]</code>
925     * @param rhs  the right hand <code>char[]</code>
926     * @return EqualsBuilder - used to chain calls.
927     */
928    public EqualsBuilder append(final char[] lhs, final char[] rhs) {
929        if (!isEquals) {
930            return this;
931        }
932        if (lhs == rhs) {
933            return this;
934        }
935        if (lhs == null || rhs == null) {
936            this.setEquals(false);
937            return this;
938        }
939        if (lhs.length != rhs.length) {
940            this.setEquals(false);
941            return this;
942        }
943        for (int i = 0; i < lhs.length && isEquals; ++i) {
944            append(lhs[i], rhs[i]);
945        }
946        return this;
947    }
948
949    /**
950     * <p>Deep comparison of array of <code>byte</code>. Length and all
951     * values are compared.</p>
952     *
953     * <p>The method {@link #append(byte, byte)} is used.</p>
954     *
955     * @param lhs  the left hand <code>byte[]</code>
956     * @param rhs  the right hand <code>byte[]</code>
957     * @return EqualsBuilder - used to chain calls.
958     */
959    public EqualsBuilder append(final byte[] lhs, final byte[] rhs) {
960        if (!isEquals) {
961            return this;
962        }
963        if (lhs == rhs) {
964            return this;
965        }
966        if (lhs == null || rhs == null) {
967            this.setEquals(false);
968            return this;
969        }
970        if (lhs.length != rhs.length) {
971            this.setEquals(false);
972            return this;
973        }
974        for (int i = 0; i < lhs.length && isEquals; ++i) {
975            append(lhs[i], rhs[i]);
976        }
977        return this;
978    }
979
980    /**
981     * <p>Deep comparison of array of <code>double</code>. Length and all
982     * values are compared.</p>
983     *
984     * <p>The method {@link #append(double, double)} is used.</p>
985     *
986     * @param lhs  the left hand <code>double[]</code>
987     * @param rhs  the right hand <code>double[]</code>
988     * @return EqualsBuilder - used to chain calls.
989     */
990    public EqualsBuilder append(final double[] lhs, final double[] rhs) {
991        if (!isEquals) {
992            return this;
993        }
994        if (lhs == rhs) {
995            return this;
996        }
997        if (lhs == null || rhs == null) {
998            this.setEquals(false);
999            return this;
1000        }
1001        if (lhs.length != rhs.length) {
1002            this.setEquals(false);
1003            return this;
1004        }
1005        for (int i = 0; i < lhs.length && isEquals; ++i) {
1006            append(lhs[i], rhs[i]);
1007        }
1008        return this;
1009    }
1010
1011    /**
1012     * <p>Deep comparison of array of <code>float</code>. Length and all
1013     * values are compared.</p>
1014     *
1015     * <p>The method {@link #append(float, float)} is used.</p>
1016     *
1017     * @param lhs  the left hand <code>float[]</code>
1018     * @param rhs  the right hand <code>float[]</code>
1019     * @return EqualsBuilder - used to chain calls.
1020     */
1021    public EqualsBuilder append(final float[] lhs, final float[] rhs) {
1022        if (!isEquals) {
1023            return this;
1024        }
1025        if (lhs == rhs) {
1026            return this;
1027        }
1028        if (lhs == null || rhs == null) {
1029            this.setEquals(false);
1030            return this;
1031        }
1032        if (lhs.length != rhs.length) {
1033            this.setEquals(false);
1034            return this;
1035        }
1036        for (int i = 0; i < lhs.length && isEquals; ++i) {
1037            append(lhs[i], rhs[i]);
1038        }
1039        return this;
1040    }
1041
1042    /**
1043     * <p>Deep comparison of array of <code>boolean</code>. Length and all
1044     * values are compared.</p>
1045     *
1046     * <p>The method {@link #append(boolean, boolean)} is used.</p>
1047     *
1048     * @param lhs  the left hand <code>boolean[]</code>
1049     * @param rhs  the right hand <code>boolean[]</code>
1050     * @return EqualsBuilder - used to chain calls.
1051     */
1052    public EqualsBuilder append(final boolean[] lhs, final boolean[] rhs) {
1053        if (!isEquals) {
1054            return this;
1055        }
1056        if (lhs == rhs) {
1057            return this;
1058        }
1059        if (lhs == null || rhs == null) {
1060            this.setEquals(false);
1061            return this;
1062        }
1063        if (lhs.length != rhs.length) {
1064            this.setEquals(false);
1065            return this;
1066        }
1067        for (int i = 0; i < lhs.length && isEquals; ++i) {
1068            append(lhs[i], rhs[i]);
1069        }
1070        return this;
1071    }
1072
1073    /**
1074     * <p>Returns <code>true</code> if the fields that have been checked
1075     * are all equal.</p>
1076     *
1077     * @return boolean
1078     */
1079    public boolean isEquals() {
1080        return this.isEquals;
1081    }
1082
1083    /**
1084     * <p>Returns <code>true</code> if the fields that have been checked
1085     * are all equal.</p>
1086     *
1087     * @return <code>true</code> if all of the fields that have been checked
1088     *         are equal, <code>false</code> otherwise.
1089     *
1090     * @since 3.0
1091     */
1092    @Override
1093    public Boolean build() {
1094        return Boolean.valueOf(isEquals());
1095    }
1096
1097    /**
1098     * Sets the <code>isEquals</code> value.
1099     *
1100     * @param isEquals The value to set.
1101     * @since 2.1
1102     */
1103    protected void setEquals(final boolean isEquals) {
1104        this.isEquals = isEquals;
1105    }
1106
1107    /**
1108     * Reset the EqualsBuilder so you can use the same object again
1109     * @since 2.5
1110     */
1111    public void reset() {
1112        this.isEquals = true;
1113    }
1114}