Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.lang.builder; import java.lang.reflect.AccessibleObject; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import java.util.Arrays; import java.util.Collections; import java.util.Collection; import java.util.Comparator; import java.util.List; import org.apache.commons.lang.math.NumberUtils; /** * Assists in implementing {@link java.lang.Comparable#compareTo(Object)} methods. * * It is consistent with <code>equals(Object)</code> and * <code>hashcode()</code> built with {@link EqualsBuilder} and * {@link HashCodeBuilder}.</p> * * <p>Two Objects that compare equal using <code>equals(Object)</code> should normally * also compare equal using <code>compareTo(Object)</code>.</p> * * <p>All relevant fields should be included in the calculation of the * comparison. Derived fields may be ignored. The same fields, in the same * order, should be used in both <code>compareTo(Object)</code> and * <code>equals(Object)</code>.</p> * * <p>To use this class write code as follows:</p> * * <pre> * public class MyClass { * String field1; * int field2; * boolean field3; * * ... * * public int compareTo(Object o) { * MyClass myClass = (MyClass) o; * return new CompareToBuilder() * .appendSuper(super.compareTo(o) * .append(this.field1, myClass.field1) * .append(this.field2, myClass.field2) * .append(this.field3, myClass.field3) * .toComparison(); * } * } * </pre> * * <p>Alternatively, there are {@link #reflectionCompare(Object, Object) reflectionCompare} methods that use * reflection to determine the fields to append. Because fields can be private, * <code>reflectionCompare</code> uses {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} to * bypass normal access control checks. This will fail under a security manager, * unless the appropriate permissions are set up correctly. It is also * slower than appending explicitly.</p> * * <p>A typical implementation of <code>compareTo(Object)</code> using * <code>reflectionCompare</code> looks like:</p> * <pre> * public int compareTo(Object o) { * return CompareToBuilder.reflectionCompare(this, o); * } * </pre> * * @see java.lang.Comparable * @see java.lang.Object#equals(Object) * @see java.lang.Object#hashCode() * @see EqualsBuilder * @see HashCodeBuilder * @author <a href="mailto:steve.downey@netfolio.com">Steve Downey</a> * @author Stephen Colebourne * @author Gary Gregory * @author Pete Gieser * @since 1.0 * @version $Id: CompareToBuilder.java 447139 2006-09-17 20:36:53Z bayard $ */ public class CompareToBuilder { /** * Current state of the comparison as appended fields are checked. */ private int comparison; /** * <p>Constructor for CompareToBuilder.</p> * * <p>Starts off assuming that the objects are equal. Multiple calls are * then made to the various append methods, followed by a call to * {@link #toComparison} to get the result.</p> */ public CompareToBuilder() { super(); comparison = 0; } //----------------------------------------------------------------------- /** * <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>Transient members will be not be compared, 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 * @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(Object lhs, Object rhs) { return reflectionCompare(lhs, rhs, false, null, 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(Object lhs, Object rhs, boolean compareTransients) { return reflectionCompare(lhs, rhs, compareTransients, null, 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(Object lhs, Object rhs, Collection /*String*/ excludeFields) { return reflectionCompare(lhs, rhs, ReflectionToStringBuilder.toNoNullStringArray(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 <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(Object lhs, Object rhs, 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 * @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 2.0 */ public static int reflectionCompare(Object lhs, Object rhs, boolean compareTransients, Class reflectUpToClass) { return reflectionCompare(lhs, rhs, false, reflectUpToClass, 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 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 */ public static int reflectionCompare(Object lhs, Object rhs, boolean compareTransients, Class reflectUpToClass, 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(); } CompareToBuilder compareToBuilder = new CompareToBuilder(); 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>CompareToBuilder</code> to append to * @param useTransients whether to compare transient fields * @param excludeFields fields to exclude */ private static void reflectionAppend(Object lhs, Object rhs, Class clazz, CompareToBuilder builder, boolean useTransients, String[] excludeFields) { Field[] fields = clazz.getDeclaredFields(); List excludedFieldList = excludeFields != null ? Arrays.asList(excludeFields) : Collections.EMPTY_LIST; AccessibleObject.setAccessible(fields, true); for (int i = 0; i < fields.length && builder.comparison == 0; i++) { Field f = fields[i]; if (!excludedFieldList.contains(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 (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"); } } } } //----------------------------------------------------------------------- /** * <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 CompareToBuilder appendSuper(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 CompareToBuilder append(Object lhs, 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 CompareToBuilder append(Object lhs, Object rhs, 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) { comparison = ((Comparable) lhs).compareTo(rhs); } else { comparison = comparator.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 CompareToBuilder append(long lhs, long rhs) { if (comparison != 0) { return this; } comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0)); 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 CompareToBuilder append(int lhs, int rhs) { if (comparison != 0) { return this; } comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0)); 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 CompareToBuilder append(short lhs, short rhs) { if (comparison != 0) { return this; } comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0)); 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 CompareToBuilder append(char lhs, char rhs) { if (comparison != 0) { return this; } comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0)); 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 CompareToBuilder append(byte lhs, byte rhs) { if (comparison != 0) { return this; } comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0)); 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 CompareToBuilder append(double lhs, double rhs) { if (comparison != 0) { return this; } comparison = NumberUtils.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 CompareToBuilder append(float lhs, float rhs) { if (comparison != 0) { return this; } comparison = NumberUtils.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 CompareToBuilder append(boolean lhs, boolean rhs) { if (comparison != 0) { return this; } if (lhs == rhs) { return this; } if (lhs == false) { 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 CompareToBuilder append(Object[] lhs, 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 CompareToBuilder append(Object[] lhs, Object[] rhs, 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 CompareToBuilder append(long[] lhs, 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 CompareToBuilder append(int[] lhs, 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 CompareToBuilder append(short[] lhs, 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 CompareToBuilder append(char[] lhs, 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 CompareToBuilder append(byte[] lhs, 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 CompareToBuilder append(double[] lhs, 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 CompareToBuilder append(float[] lhs, 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 CompareToBuilder append(boolean[] lhs, 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 */ public int toComparison() { return comparison; } }