09-BeanCompareUtil

快速比较两个对象所有字段值：

还在担心对象字段太多？有了这个，真香。

1. 测试代码

import java.util.HashMap;
import java.util.Map;

/**
 * @Class: BeanCompareTest
 * @Description:
 * @Author: Jerry(姜源)
 * @Create: 20/12/2 16:15
 */
@SuppressWarnings("all")
public class BeanCompareTest {
    public static void main(String[] args) {
        Student s1 = new Student();
        s1.setName("张三");
        s1.setAge(22);
        s1.setSex(false);
        Student s2 = new Student();
        s2.setName("李四");
        s2.setAge(22);
        s2.setSex(false);
        //比较两个不一样的Bean
        int r1 = BeanCompareUtil.reflectionCompare(s1, s2);
        System.out.println("r1 = " + r1); //-2094 字段有不同
        //比较两个不一样的Bean，排除不同的字段，剩下比较相同的字段
        int r2 = BeanCompareUtil.reflectionCompare(s1, s2, "name", "sex");
        System.out.println("r2 = " + r2); //0 字段都相同

        Student s3 = new Student();
        s3.setName("李四");
        s3.setAge(22);
        s3.setSex(false);
        //比较两个相同的Bean
        int r3 = BeanCompareUtil.reflectionCompare(s2, s3);
        System.out.println("r3 = " + r3); //0 字段都相同

        Map<String, Object> s4 = new HashMap<>();
        s4.put("name", "李四");
        s4.put("age", 22);
        s4.put("sex", false);
        Map<String, Object> s5 = new HashMap<>();
        s5.put("name", "李四");
        s5.put("age", 22);
        s5.put("sex", true);
        //比较两个相同的集合(也可行)
        int r5 = BeanCompareUtil.reflectionCompare(s4, s5, "sex");
        System.out.println("r5 = " + r5); //0 字段都相同
    }
}

class Student {
    private String name;
    private Integer age;
    private Boolean sex;
    public Student() {}
    public String getName() {return name;}
    public void setName(String name) {this.name = name;}
    public Integer getAge() {return age;}
    public void setAge(Integer age) {this.age = age;}
    public Boolean getSex() {return sex;}
    public void setSex(Boolean sex) {this.sex = sex;}
}

2. 工具类

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.math.BigDecimal;
import java.util.*;
import java.util.stream.Collectors;

/**
 * @Class: BeanCompareUtil
 * @Description: 比较两个Bean对象的值是否相等
 * @Author: Jerry(姜源)
 * @Create: 20/12/2 16:21
 */

public class BeanCompareUtil {
    /** 当前比较状态 */
    private int comparison;

    /**
     * 构造，构造后调用append方法增加比较项，然后调用{@link #toComparison()}获取结果
     */
    public BeanCompareUtil() {
        super();
        comparison = 0;
    }

    //-----------------------------------------------------------------------
    /**
     * 通过反射比较两个Bean对象，对象字段可以为private。比较规则如下：
     *
     * <ul>
     * <li>static字段不比较</li>
     * <li>Transient字段不参与比较</li>
     * <li>父类字段参与比较</li>
     * </ul>
     *
     *<p>
     *如果被比较的两个对象都为<code>null</code>，被认为相同。
     *
     * @param lhs  第一个对象
     * @param rhs  第二个对象
     * @return a negative integer, zero, or a positive integer as <code>lhs</code>
     *  is less than, equal to, or greater than <code>rhs</code>
     * @throws NullPointerException  if either (but not both) parameters are
     *  <code>null</code>
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     */
    public static int reflectionCompare(final Object lhs, final Object rhs) {
        return reflectionCompare(lhs, rhs, false, null);
    }

    /**
     * <p>Compares two <code>Object</code>s via reflection.</p>
     *
     * <p>Fields can be private, thus <code>AccessibleObject.setAccessible</code>
     * is used to bypass normal access control checks. This will fail under a
     * security manager unless the appropriate permissions are set.</p>
     *
     * <ul>
     * <li>Static fields will not be compared</li>
     * <li>If <code>compareTransients</code> is <code>true</code>,
     *     compares transient members.  Otherwise ignores them, as they
     *     are likely derived fields.</li>
     * <li>Superclass fields will be compared</li>
     * </ul>
     *
     * <p>If both <code>lhs</code> and <code>rhs</code> are <code>null</code>,
     * they are considered equal.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param compareTransients  whether to compare transient fields
     * @return a negative integer, zero, or a positive integer as <code>lhs</code>
     *  is less than, equal to, or greater than <code>rhs</code>
     * @throws NullPointerException  if either <code>lhs</code> or <code>rhs</code>
     *  (but not both) is <code>null</code>
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     */
    public static int reflectionCompare(final Object lhs, final Object rhs, final boolean compareTransients) {
        return reflectionCompare(lhs, rhs, compareTransients, null);
    }

    /**
     * <p>Compares two <code>Object</code>s via reflection.</p>
     *
     * <p>Fields can be private, thus <code>AccessibleObject.setAccessible</code>
     * is used to bypass normal access control checks. This will fail under a
     * security manager unless the appropriate permissions are set.</p>
     *
     * <ul>
     * <li>Static fields will not be compared</li>
     * <li>If <code>compareTransients</code> is <code>true</code>,
     *     compares transient members.  Otherwise ignores them, as they
     *     are likely derived fields.</li>
     * <li>Superclass fields will be compared</li>
     * </ul>
     *
     * <p>If both <code>lhs</code> and <code>rhs</code> are <code>null</code>,
     * they are considered equal.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param excludeFields  Collection of String fields to exclude
     * @return a negative integer, zero, or a positive integer as <code>lhs</code>
     *  is less than, equal to, or greater than <code>rhs</code>
     * @throws NullPointerException  if either <code>lhs</code> or <code>rhs</code>
     *  (but not both) is <code>null</code>
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     * @since 2.2
     */
    public static int reflectionCompare(final Object lhs, final Object rhs, final Collection<String> excludeFields) {
        return reflectionCompare(lhs, rhs, toArray(excludeFields, String.class));
    }

    /**
     * 将集合转为数组
     *
     * @param <T>           数组元素类型
     * @param collection    集合
     * @param componentType 集合元素类型
     * @return 数组
     * @since 3.0.9
     */
    private static <T> T[] toArray(Collection<T> collection, Class<T> componentType) {
        return collection.toArray(newArray(componentType, 0));
    }

    /**
     * 新建一个空数组
     *
     * @param <T>           数组元素类型
     * @param componentType 元素类型
     * @param newSize       大小
     * @return 空数组
     */
    @SuppressWarnings("unchecked")
    public static <T> T[] newArray(Class<?> componentType, int newSize) {
        return (T[]) Array.newInstance(componentType, newSize);
    }

    /**
     * <p>Compares two <code>Object</code>s via reflection.</p>
     *
     * <p>Fields can be private, thus <code>AccessibleObject.setAccessible</code>
     * is used to bypass normal access control checks. This will fail under a
     * security manager unless the appropriate permissions are set.</p>
     *
     * <ul>
     * <li>Static fields will not be compared</li>
     * <li>If <code>compareTransients</code> is <code>true</code>,
     *     compares transient members.  Otherwise ignores them, as they
     *     are likely derived fields.</li>
     * <li>Superclass fields will be compared</li>
     * </ul>
     *
     * <p>If both <code>lhs</code> and <code>rhs</code> are <code>null</code>,
     * they are considered equal.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param excludeFields  array of fields to exclude
     * @return a negative integer, zero, or a positive integer as <code>lhs</code>
     *  is less than, equal to, or greater than <code>rhs</code>
     * @throws NullPointerException  if either <code>lhs</code> or <code>rhs</code>
     *  (but not both) is <code>null</code>
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     * @since 2.2
     */
    public static int reflectionCompare(final Object lhs, final Object rhs, final String... excludeFields) {
        return reflectionCompare(lhs, rhs, false, null, excludeFields);
    }

    /**
     * <p>Compares two <code>Object</code>s via reflection.</p>
     *
     * <p>Fields can be private, thus <code>AccessibleObject.setAccessible</code>
     * is used to bypass normal access control checks. This will fail under a
     * security manager unless the appropriate permissions are set.</p>
     *
     * <ul>
     * <li>Static fields will not be compared</li>
     * <li>If the <code>compareTransients</code> is <code>true</code>,
     *     compares transient members.  Otherwise ignores them, as they
     *     are likely derived fields.</li>
     * <li>Compares superclass fields up to and including <code>reflectUpToClass</code>.
     *     If <code>reflectUpToClass</code> is <code>null</code>, compares all superclass fields.</li>
     * </ul>
     *
     * <p>If both <code>lhs</code> and <code>rhs</code> are <code>null</code>,
     * they are considered equal.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param compareTransients  whether to compare transient fields
     * @param reflectUpToClass  last superclass for which fields are compared
     * @param excludeFields  fields to exclude
     * @return a negative integer, zero, or a positive integer as <code>lhs</code>
     *  is less than, equal to, or greater than <code>rhs</code>
     * @throws NullPointerException  if either <code>lhs</code> or <code>rhs</code>
     *  (but not both) is <code>null</code>
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     * @since 2.2 (2.0 as <code>reflectionCompare(Object, Object, boolean, Class)</code>)
     */
    public static int reflectionCompare(
            final Object lhs,
            final Object rhs,
            final boolean compareTransients,
            final Class<?> reflectUpToClass,
            final String... excludeFields) {

        if (lhs == rhs) {
            return 0;
        }
        if (lhs == null || rhs == null) {
            throw new NullPointerException();
        }
        Class<?> lhsClazz = lhs.getClass();
        //if (!lhsClazz.isInstance(rhs)) {
        //    throw new ClassCastException();
        //}
        //如果两者都不是代理类，才需要检查类的类型，否则代理类对象与普通类对象判断时此处会抛异常(Jerry 2020-12-3 10:25:04)
        if (!(lhsClazz.getName().endsWith("$Proxy") || rhs.getClass().getName().endsWith("$Proxy"))) {
            if (!lhsClazz.isInstance(rhs)) {
                throw new ClassCastException();
            }
        }
        final BeanCompareUtil compareToBuilder = new BeanCompareUtil();
        reflectionAppend(lhs, rhs, lhsClazz, compareToBuilder, compareTransients, excludeFields);
        while (lhsClazz.getSuperclass() != null && lhsClazz != reflectUpToClass) {
            lhsClazz = lhsClazz.getSuperclass();
            reflectionAppend(lhs, rhs, lhsClazz, compareToBuilder, compareTransients, excludeFields);
        }
        return compareToBuilder.toComparison();
    }

    /**
     * <p>Appends to <code>builder</code> the comparison of <code>lhs</code>
     * to <code>rhs</code> using the fields defined in <code>clazz</code>.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param clazz  <code>Class</code> that defines fields to be compared
     * @param builder  <code>BeanCompareUtil</code> to append to
     * @param useTransients  whether to compare transient fields
     * @param excludeFields  fields to exclude
     */
    private static void reflectionAppend(
            final Object lhs,
            final Object rhs,
            final Class<?> clazz,
            final BeanCompareUtil builder,
            final boolean useTransients,
            final String[] excludeFields) {

        //针对代理类中会包含 __updateProps__ 字段进行过滤，否则导致代理类对象与原Bean对象判断会因无法 setAccessible 而抛异常(Jerry 2020-12-3 10:25:04)
        Field[] fields = clazz.getDeclaredFields();
        List<Field> fieldList = Arrays.stream(fields).filter(e -> !e.getName().endsWith("__updateProps__")).collect(Collectors.toList());
        fields = fieldList.toArray(new Field[0]);
        
        AccessibleObject.setAccessible(fields, true);
        for (int i = 0; i < fields.length && builder.comparison == 0; i++) {
            final Field f = fields[i];
            if (!contains(excludeFields, f.getName())
                    && (f.getName().indexOf('$') == -1)
                    && (useTransients || !Modifier.isTransient(f.getModifiers()))
                    && (!Modifier.isStatic(f.getModifiers()))) {
                try {
                    builder.append(f.get(lhs), f.get(rhs));
                } catch (final IllegalAccessException e) {
                    // This can't happen. Would get a Security exception instead.
                    // Throw a runtime exception in case the impossible happens.
                    throw new InternalError("Unexpected IllegalAccessException");
                }
            }
        }
    }

    /**
     * 数组中是否包含元素
     */
    private static <T> boolean contains(T[] array, T value) {
        return indexOf(array, value) > -1;
    }

    /**
     * 返回数组中指定元素所在位置，未找到返回
     */
    private static <T> int indexOf(T[] array, Object value) {
        if (null != array) {
            for (int i = 0; i < array.length; i++) {
                if (equal(value, array[i])) {
                    return i;
                }
            }
        }
        return -1;
    }

    /**
     * 比较两个数组元素对象是否相等
     */
    private static boolean equal(Object obj1, Object obj2) {
        if (obj1 instanceof BigDecimal && obj2 instanceof BigDecimal) {
            return 0 == ((BigDecimal) obj1).compareTo((BigDecimal) obj2);
        }
        return Objects.equals(obj1, obj2);
    }

    //-----------------------------------------------------------------------
    /**
     * <p>Appends to the <code>builder</code> the <code>compareTo(Object)</code>
     * result of the superclass.</p>
     *
     * @param superCompareTo  result of calling <code>super.compareTo(Object)</code>
     * @return this - used to chain append calls
     * @since 2.0
     */
    public BeanCompareUtil appendSuper(final int superCompareTo) {
        if (comparison != 0) {
            return this;
        }
        comparison = superCompareTo;
        return this;
    }

    //-----------------------------------------------------------------------
    /**
     * <p>Appends to the <code>builder</code> the comparison of
     * two <code>Object</code>s.</p>
     *
     * <ol>
     * <li>Check if <code>lhs == rhs</code></li>
     * <li>Check if either <code>lhs</code> or <code>rhs</code> is <code>null</code>,
     *     a <code>null</code> object is less than a non-<code>null</code> object</li>
     * <li>Check the object contents</li>
     * </ol>
     *
     * <p><code>lhs</code> must either be an array or implement {@link Comparable}.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @return this - used to chain append calls
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     */
    public BeanCompareUtil append(final Object lhs, final Object rhs) {
        return append(lhs, rhs, null);
    }

    /**
     * <p>Appends to the <code>builder</code> the comparison of
     * two <code>Object</code>s.</p>
     *
     * <ol>
     * <li>Check if <code>lhs == rhs</code></li>
     * <li>Check if either <code>lhs</code> or <code>rhs</code> is <code>null</code>,
     *     a <code>null</code> object is less than a non-<code>null</code> object</li>
     * <li>Check the object contents</li>
     * </ol>
     *
     * <p>If <code>lhs</code> is an array, array comparison methods will be used.
     * Otherwise <code>comparator</code> will be used to compare the objects.
     * If <code>comparator</code> is <code>null</code>, <code>lhs</code> must
     * implement {@link Comparable} instead.</p>
     *
     * @param lhs  left-hand object
     * @param rhs  right-hand object
     * @param comparator  <code>Comparator</code> used to compare the objects,
     *  <code>null</code> means treat lhs as <code>Comparable</code>
     * @return this - used to chain append calls
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     * @since 2.0
     */
    public BeanCompareUtil append(final Object lhs, final Object rhs, final Comparator<?> comparator) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.getClass().isArray()) {
            // switch on type of array, to dispatch to the correct handler
            // handles multi dimensional arrays
            // throws a ClassCastException if rhs is not the correct array type
            if (lhs instanceof long[]) {
                append((long[]) lhs, (long[]) rhs);
            } else if (lhs instanceof int[]) {
                append((int[]) lhs, (int[]) rhs);
            } else if (lhs instanceof short[]) {
                append((short[]) lhs, (short[]) rhs);
            } else if (lhs instanceof char[]) {
                append((char[]) lhs, (char[]) rhs);
            } else if (lhs instanceof byte[]) {
                append((byte[]) lhs, (byte[]) rhs);
            } else if (lhs instanceof double[]) {
                append((double[]) lhs, (double[]) rhs);
            } else if (lhs instanceof float[]) {
                append((float[]) lhs, (float[]) rhs);
            } else if (lhs instanceof boolean[]) {
                append((boolean[]) lhs, (boolean[]) rhs);
            } else {
                // not an array of primitives
                // throws a ClassCastException if rhs is not an array
                append((Object[]) lhs, (Object[]) rhs, comparator);
            }
        } else {
            // the simple case, not an array, just test the element
            if (comparator == null) {
                @SuppressWarnings("unchecked") // assume this can be done; if not throw CCE as per Javadoc
                final Comparable<Object> comparable = (Comparable<Object>) lhs;
                comparison = comparable.compareTo(rhs);
            } else {
                @SuppressWarnings("unchecked") // assume this can be done; if not throw CCE as per Javadoc
                final Comparator<Object> comparator2 = (Comparator<Object>) comparator;
                comparison = comparator2.compare(lhs, rhs);
            }
        }
        return this;
    }

    //-------------------------------------------------------------------------
    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>long</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final long lhs, final long rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = (Long.compare(lhs, rhs));
        return this;
    }

    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>int</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final int lhs, final int rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = (Integer.compare(lhs, rhs));
        return this;
    }

    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>short</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final short lhs, final short rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = (Short.compare(lhs, rhs));
        return this;
    }

    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>char</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final char lhs, final char rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = (Character.compare(lhs, rhs));
        return this;
    }

    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>byte</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final byte lhs, final byte rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = (Byte.compare(lhs, rhs));
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the comparison of
     * two <code>double</code>s.</p>
     *
     * <p>This handles NaNs, Infinities, and <code>-0.0</code>.</p>
     *
     * <p>It is compatible with the hash code generated by
     * <code>HashCodeBuilder</code>.</p>
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final double lhs, final double rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = Double.compare(lhs, rhs);
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the comparison of
     * two <code>float</code>s.</p>
     *
     * <p>This handles NaNs, Infinities, and <code>-0.0</code>.</p>
     *
     * <p>It is compatible with the hash code generated by
     * <code>HashCodeBuilder</code>.</p>
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final float lhs, final float rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = Float.compare(lhs, rhs);
        return this;
    }

    /**
     * Appends to the <code>builder</code> the comparison of
     * two <code>booleans</code>s.
     *
     * @param lhs  left-hand value
     * @param rhs  right-hand value
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final boolean lhs, final boolean rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (!lhs) {
            comparison = -1;
        } else {
            comparison = +1;
        }
        return this;
    }

    //-----------------------------------------------------------------------
    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>Object</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a short length array is less than a long length array</li>
     *  <li>Check array contents element by element using {@link #append(Object, Object, Comparator)}</li>
     * </ol>
     *
     * <p>This method will also will be called for the top level of multi-dimensional,
     * ragged, and multi-typed arrays.</p>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     */
    public BeanCompareUtil append(final Object[] lhs, final Object[] rhs) {
        return append(lhs, rhs, null);
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>Object</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a short length array is less than a long length array</li>
     *  <li>Check array contents element by element using {@link #append(Object, Object, Comparator)}</li>
     * </ol>
     *
     * <p>This method will also will be called for the top level of multi-dimensional,
     * ragged, and multi-typed arrays.</p>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @param comparator  <code>Comparator</code> to use to compare the array elements,
     *  <code>null</code> means to treat <code>lhs</code> elements as <code>Comparable</code>.
     * @return this - used to chain append calls
     * @throws ClassCastException  if <code>rhs</code> is not assignment-compatible
     *  with <code>lhs</code>
     * @since 2.0
     */
    public BeanCompareUtil append(final Object[] lhs, final Object[] rhs, final Comparator<?> comparator) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i], comparator);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>long</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(long, long)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final long[] lhs, final long[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>int</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(int, int)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final int[] lhs, final int[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>short</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(short, short)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final short[] lhs, final short[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>char</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(char, char)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final char[] lhs, final char[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>byte</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(byte, byte)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final byte[] lhs, final byte[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>double</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(double, double)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final double[] lhs, final double[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>float</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(float, float)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final float[] lhs, final float[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    /**
     * <p>Appends to the <code>builder</code> the deep comparison of
     * two <code>boolean</code> arrays.</p>
     *
     * <ol>
     *  <li>Check if arrays are the same using <code>==</code></li>
     *  <li>Check if for <code>null</code>, <code>null</code> is less than non-<code>null</code></li>
     *  <li>Check array length, a shorter length array is less than a longer length array</li>
     *  <li>Check array contents element by element using {@link #append(boolean, boolean)}</li>
     * </ol>
     *
     * @param lhs  left-hand array
     * @param rhs  right-hand array
     * @return this - used to chain append calls
     */
    public BeanCompareUtil append(final boolean[] lhs, final boolean[] rhs) {
        if (comparison != 0) {
            return this;
        }
        if (lhs == rhs) {
            return this;
        }
        if (lhs == null) {
            comparison = -1;
            return this;
        }
        if (rhs == null) {
            comparison = +1;
            return this;
        }
        if (lhs.length != rhs.length) {
            comparison = (lhs.length < rhs.length) ? -1 : +1;
            return this;
        }
        for (int i = 0; i < lhs.length && comparison == 0; i++) {
            append(lhs[i], rhs[i]);
        }
        return this;
    }

    //-----------------------------------------------------------------------
    /**
     * Returns a negative integer, a positive integer, or zero as
     * the <code>builder</code> has judged the "left-hand" side
     * as less than, greater than, or equal to the "right-hand"
     * side.
     *
     * @return final comparison result
     * @see #build()
     */
    public int toComparison() {
        return comparison;
    }

    /**
     * Returns a negative Integer, a positive Integer, or zero as
     * the <code>builder</code> has judged the "left-hand" side
     * as less than, greater than, or equal to the "right-hand"
     * side.
     *
     * @return final comparison result as an Integer
     * @see #toComparison()
     * @since 3.0
     */
    public Integer build() {
        return toComparison();
    }
}