package vnet.sms.common.shell.springshell.internal.util; import java.lang.reflect.Array; import java.util.Arrays; /** * Miscellaneous object utility methods. Mainly for internal use within the * framework; consider Jakarta's Commons Lang for a more comprehensive suite of * object utilities. * * @author Juergen Hoeller * @author Keith Donald * @author Rod Johnson * @author Rob Harrop * @author Alex Ruiz * @see org.apache.commons.lang.ObjectUtils */ public final class ObjectUtils { // Constants private static final int INITIAL_HASH = 7; private static final int MULTIPLIER = 31; private static final String EMPTY_STRING = ""; private static final String NULL_STRING = "null"; private static final String ARRAY_START = "{"; private static final String ARRAY_END = "}"; private static final String EMPTY_ARRAY = ARRAY_START + ARRAY_END; private static final String ARRAY_ELEMENT_SEPARATOR = ", "; /** * Return whether the given throwable is a checked exception: that is, * neither a RuntimeException nor an Error. * * @param ex * the throwable to check * @return whether the throwable is a checked exception * @see java.lang.Exception * @see java.lang.RuntimeException * @see java.lang.Error */ public static boolean isCheckedException(final Throwable ex) { return !((ex instanceof RuntimeException) || (ex instanceof Error)); } /** * Check whether the given exception is compatible with the exceptions * declared in a throws clause. * * @param ex * the exception to checked * @param declaredExceptions * the exceptions declared in the throws clause * @return whether the given exception is compatible */ public static boolean isCompatibleWithThrowsClause(final Throwable ex, final Class<?>... declaredExceptions) { if (!isCheckedException(ex)) { return true; } if (declaredExceptions != null) { int i = 0; while (i < declaredExceptions.length) { if (declaredExceptions[i].isAssignableFrom(ex.getClass())) { return true; } i++; } } return false; } /** * Return whether the given array is empty: that is, <code>null</code> or of * zero length. * * @param array * the array to check * @return whether the given array is empty */ public static boolean isEmpty(final Object[] array) { return (array == null) || (array.length == 0); } /** * Check whether the given array contains the given element. * * @param array * the array to check (may be <code>null</code>, in which case * the return value will always be <code>false</code>) * @param element * the element to check for * @return whether the element has been found in the given array */ public static boolean containsElement(final Object[] array, final Object element) { if (array == null) { return false; } for (final Object arrayEle : array) { if (nullSafeEquals(arrayEle, element)) { return true; } } return false; } /** * Append the given Object to the given array, returning a new array * consisting of the input array contents plus the given Object. * * @param array * the array to append to (can be <code>null</code>) * @param obj * the Object to append * @return the new array (of the same component type; never * <code>null</code>) */ public static Object[] addObjectToArray(final Object[] array, final Object obj) { Class<?> compType = Object.class; if (array != null) { compType = array.getClass().getComponentType(); } else if (obj != null) { compType = obj.getClass(); } final int newArrLength = (array != null ? array.length + 1 : 1); final Object[] newArr = (Object[]) Array.newInstance(compType, newArrLength); if (array != null) { System.arraycopy(array, 0, newArr, 0, array.length); } newArr[newArr.length - 1] = obj; return newArr; } /** * Convert the given array (which may be a primitive array) to an object * array (if necessary of primitive wrapper objects). * <p> * A <code>null</code> source value will be converted to an empty Object * array. * * @param source * the (potentially primitive) array * @return the corresponding object array (never <code>null</code>) * @throws IllegalArgumentException * if the parameter is not an array */ public static Object[] toObjectArray(final Object source) { if (source instanceof Object[]) { return (Object[]) source; } if (source == null) { return new Object[0]; } if (!source.getClass().isArray()) { throw new IllegalArgumentException("Source is not an array: " + source); } final int length = Array.getLength(source); if (length == 0) { return new Object[0]; } final Class<?> wrapperType = Array.get(source, 0).getClass(); final Object[] newArray = (Object[]) Array.newInstance(wrapperType, length); for (int i = 0; i < length; i++) { newArray[i] = Array.get(source, i); } return newArray; } // --------------------------------------------------------------------- // Convenience methods for content-based equality/hash-code handling // --------------------------------------------------------------------- /** * Determine if the given objects are equal, returning <code>true</code> if * both are <code>null</code> or <code>false</code> if only one is * <code>null</code>. * <p> * Compares arrays with <code>Arrays.equals</code>, performing an equality * check based on the array elements rather than the array reference. * * @param o1 * first Object to compare * @param o2 * second Object to compare * @return whether the given objects are equal * @see java.util.Arrays#equals */ public static boolean nullSafeEquals(final Object o1, final Object o2) { if (o1 == o2) { return true; } if ((o1 == null) || (o2 == null)) { return false; } if (o1.equals(o2)) { return true; } if (o1.getClass().isArray() && o2.getClass().isArray()) { if ((o1 instanceof Object[]) && (o2 instanceof Object[])) { return Arrays.equals((Object[]) o1, (Object[]) o2); } if ((o1 instanceof boolean[]) && (o2 instanceof boolean[])) { return Arrays.equals((boolean[]) o1, (boolean[]) o2); } if ((o1 instanceof byte[]) && (o2 instanceof byte[])) { return Arrays.equals((byte[]) o1, (byte[]) o2); } if ((o1 instanceof char[]) && (o2 instanceof char[])) { return Arrays.equals((char[]) o1, (char[]) o2); } if ((o1 instanceof double[]) && (o2 instanceof double[])) { return Arrays.equals((double[]) o1, (double[]) o2); } if ((o1 instanceof float[]) && (o2 instanceof float[])) { return Arrays.equals((float[]) o1, (float[]) o2); } if ((o1 instanceof int[]) && (o2 instanceof int[])) { return Arrays.equals((int[]) o1, (int[]) o2); } if ((o1 instanceof long[]) && (o2 instanceof long[])) { return Arrays.equals((long[]) o1, (long[]) o2); } if ((o1 instanceof short[]) && (o2 instanceof short[])) { return Arrays.equals((short[]) o1, (short[]) o2); } } return false; } /** * Return as hash code for the given object; typically the value of * <code>{@link Object#hashCode()}</code>. If the object is an array, this * method will delegate to any of the <code>nullSafeHashCode</code> methods * for arrays in this class. If the object is <code>null</code>, this method * returns 0. * * @see #nullSafeHashCode(Object[]) * @see #nullSafeHashCode(boolean[]) * @see #nullSafeHashCode(byte[]) * @see #nullSafeHashCode(char[]) * @see #nullSafeHashCode(double[]) * @see #nullSafeHashCode(float[]) * @see #nullSafeHashCode(int[]) * @see #nullSafeHashCode(long[]) * @see #nullSafeHashCode(short[]) */ public static int nullSafeHashCode(final Object obj) { if (obj == null) { return 0; } if (obj.getClass().isArray()) { if (obj instanceof Object[]) { return nullSafeHashCode((Object[]) obj); } if (obj instanceof boolean[]) { return nullSafeHashCode((boolean[]) obj); } if (obj instanceof byte[]) { return nullSafeHashCode((byte[]) obj); } if (obj instanceof char[]) { return nullSafeHashCode((char[]) obj); } if (obj instanceof double[]) { return nullSafeHashCode((double[]) obj); } if (obj instanceof float[]) { return nullSafeHashCode((float[]) obj); } if (obj instanceof int[]) { return nullSafeHashCode((int[]) obj); } if (obj instanceof long[]) { return nullSafeHashCode((long[]) obj); } if (obj instanceof short[]) { return nullSafeHashCode((short[]) obj); } } return obj.hashCode(); } /** * Return a hash code based on the contents of the specified array. * * @param array * the array from whose elements to calculate the hash code (can * be <code>null</code>) * @return 0 if the array is <code>null</code> */ public static int nullSafeHashCode(final Object... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; for (final Object element : array) { hash = MULTIPLIER * hash + nullSafeHashCode(element); } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final boolean... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + hashCode(array[i]); } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final byte... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + array[i]; } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final char... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + array[i]; } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final double... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + hashCode(array[i]); } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final float... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + hashCode(array[i]); } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final int... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + array[i]; } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final long... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + hashCode(array[i]); } return hash; } /** * Return a hash code based on the contents of the specified array. * * @param array * can be <code>null</code> * @return 0 if <code>array</code> is <code>null</code> */ public static int nullSafeHashCode(final short... array) { if (array == null) { return 0; } int hash = INITIAL_HASH; final int arraySize = array.length; for (int i = 0; i < arraySize; i++) { hash = MULTIPLIER * hash + array[i]; } return hash; } /** * Returns the hash code of the given boolean value. * * @param bool * the boolean for which to return the hash code * @return see {@link Boolean#hashCode()} */ public static int hashCode(final boolean bool) { return Boolean.valueOf(bool).hashCode(); } /** * Return the same value as <code>{@link Double#hashCode()}</code>. * * @see Double#hashCode() */ public static int hashCode(final double dbl) { final long bits = Double.doubleToLongBits(dbl); return hashCode(bits); } /** * Return the same value as <code>{@link Float#hashCode()}</code>. * * @see Float#hashCode() */ public static int hashCode(final float flt) { return Float.floatToIntBits(flt); } /** * Return the same value as <code>{@link Long#hashCode()}</code>. * * @see Long#hashCode() */ public static int hashCode(final long lng) { return (int) (lng ^ (lng >>> 32)); } // --------------------------------------------------------------------- // Convenience methods for toString output // --------------------------------------------------------------------- /** * Return a String representation of an object's overall identity. * * @param obj * the object (may be <code>null</code>) * @return the object's identity as String representation, or an empty * String if the object was <code>null</code> */ public static String identityToString(final Object obj) { if (obj == null) { return EMPTY_STRING; } return obj.getClass().getName() + "@" + getIdentityHexString(obj); } /** * Return a hex String form of an object's identity hash code. * * @param obj * the object * @return the object's identity code in hex notation */ public static String getIdentityHexString(final Object obj) { return Integer.toHexString(System.identityHashCode(obj)); } /** * Return a content-based String representation if <code>obj</code> is not * <code>null</code>; otherwise returns an empty String. * <p> * Differs from {@link #nullSafeToString(Object)} in that it returns an * empty String rather than "null" for a <code>null</code> value. * * @param obj * the object to build a display String for * @return a display String representation of <code>obj</code> * @see #nullSafeToString(Object) */ public static String getDisplayString(final Object obj) { if (obj == null) { return EMPTY_STRING; } return nullSafeToString(obj); } /** * Determine the class name for the given object. * <p> * Returns <code>"null"</code> if <code>obj</code> is <code>null</code>. * * @param obj * the object to introspect (may be <code>null</code>) * @return the corresponding class name */ public static String nullSafeClassName(final Object obj) { return (obj != null ? obj.getClass().getName() : NULL_STRING); } /** * Return a String representation of the specified Object. * <p> * Builds a String representation of the contents in case of an array. * Returns <code>"null"</code> if <code>obj</code> is <code>null</code>. * * @param obj * the object to build a String representation for * @return a String representation of <code>obj</code> */ public static String nullSafeToString(final Object obj) { if (obj == null) { return NULL_STRING; } if (obj instanceof String) { return (String) obj; } if (obj instanceof Object[]) { return nullSafeToString((Object[]) obj); } if (obj instanceof boolean[]) { return nullSafeToString((boolean[]) obj); } if (obj instanceof byte[]) { return nullSafeToString((byte[]) obj); } if (obj instanceof char[]) { return nullSafeToString((char[]) obj); } if (obj instanceof double[]) { return nullSafeToString((double[]) obj); } if (obj instanceof float[]) { return nullSafeToString((float[]) obj); } if (obj instanceof int[]) { return nullSafeToString((int[]) obj); } if (obj instanceof long[]) { return nullSafeToString((long[]) obj); } if (obj instanceof short[]) { return nullSafeToString((short[]) obj); } final String str = obj.toString(); return (str != null ? str : EMPTY_STRING); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final Object... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(String.valueOf(array[i])); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final boolean... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final byte... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final char... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append("'").append(array[i]).append("'"); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final double... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final float... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final int... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final long... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Return a String representation of the contents of the specified array. * <p> * The String representation consists of a list of the array's elements, * enclosed in curly braces (<code>"{}"</code>). Adjacent elements are * separated by the characters <code>", "</code> (a comma followed by a * space). Returns <code>"null"</code> if <code>array</code> is * <code>null</code>. * * @param array * the array to build a String representation for * @return a String representation of <code>array</code> */ public static String nullSafeToString(final short... array) { if (array == null) { return NULL_STRING; } final int length = array.length; if (length == 0) { return EMPTY_ARRAY; } final StringBuilder sb = new StringBuilder(); for (int i = 0; i < length; i++) { if (i == 0) { sb.append(ARRAY_START); } else { sb.append(ARRAY_ELEMENT_SEPARATOR); } sb.append(array[i]); } sb.append(ARRAY_END); return sb.toString(); } /** * Compares the two given objects, with <code>null</code> equivalent to * <code>null</code> and <code>null</code> "less than" any non- * <code>null</code> instance. Two non-<code>null</code> instances are * compared using the first one's {@link Comparable#compareTo(Object)} * method. * * @param <T> * the type of objects being compared * @param one * the first object being compared (can be <code>null</code>) * @param other * the second object being compared (can be <code>null</code>) * @return see {@link Comparable#compareTo(Object)} * @since 1.2.0 */ public static <T> int nullSafeComparison(final Comparable<T> one, final T other) { if (one == null) { if (other == null) { return 0; } // First is null, second is not return -1; } // If we get here, the first object is non-null if (other == null) { return 1; } return one.compareTo(other); } /** * Returns the String representation of the given object, or if it's * <code>null</code>, the given default string * * @param object * the object to represent as a String (can be <code>null</code>) * @param defaultValue * the value to return if the given object is <code>null</code> * (can itself be blank) * @return see above * @since 1.2.0 */ public static String toString(final Object object, final String defaultValue) { if (object == null) { return defaultValue; } return object.toString(); } /** * Returns the given object if not <code>null</code>, otherwise the given * default value * * @param <T> * the type of object being defaulted * @param object * the object to check (can be <code>null</code>) * @param defaultValue * the default value (can be <code>null</code>) * @return <code>null</code> iff both values are <code>null</code> * @since 1.2.0 */ public static <T> T defaultIfNull(final T object, final T defaultValue) { if (object == null) { return defaultValue; } return object; } /** * Constructor is private to prevent instantiation */ private ObjectUtils() { } }