null
- * or of zero length.
- * @param array the array to check
- * @return whether the given array is empty
- */
- public static boolean isEmpty(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 null,
- * in which case the return value will always be false)
- * @param element the element to check for
- * @return whether the element has been found in the given array
- */
- public static boolean containsElement(Object[] array, Object element) {
- if (array == null) {
- return false;
- }
- for (int i = 0; i < array.length; i++) {
- if (nullSafeEquals(array[i], 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 null)
- * @param obj the Object to append
- * @return the new array (of the same component type; never null)
- */
- public static Object[] addObjectToArray(Object[] array, Object obj) {
- Class compType = Object.class;
- if (array != null) {
- compType = array.getClass().getComponentType();
- }
- else if (obj != null) {
- compType = obj.getClass();
- }
- int newArrLength = (array != null ? array.length + 1 : 1);
- 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).
- * A null source value will be converted to an
- * empty Object array.
- * @param source the (potentially primitive) array
- * @return the corresponding object array (never null)
- * @throws IllegalArgumentException if the parameter is not an array
- */
- public static Object[] toObjectArray(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);
- }
- int length = Array.getLength(source);
- if (length == 0) {
- return new Object[0];
- }
- Class wrapperType = Array.get(source, 0).getClass();
- 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 true
- * if both are null or false if only one is
- * null.
- *
Compares arrays with Arrays.equals, 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(Object o1, 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
- * {@link Object#hashCode()}. If the object is an array,
- * this method will delegate to any of the nullSafeHashCode
- * methods for arrays in this class. If the object is null,
- * 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(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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(Object[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- int arraySize = array.length;
- for (int i = 0; i < arraySize; i++) {
- hash = MULTIPLIER * hash + nullSafeHashCode(array[i]);
- }
- return hash;
- }
-
- /**
- * Return a hash code based on the contents of the specified array.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(boolean[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(byte[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(char[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(double[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(float[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(int[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(long[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- 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.
- * If array is null, this method returns 0.
- */
- public static int nullSafeHashCode(short[] array) {
- if (array == null) {
- return 0;
- }
- int hash = INITIAL_HASH;
- int arraySize = array.length;
- for (int i = 0; i < arraySize; i++) {
- hash = MULTIPLIER * hash + array[i];
- }
- return hash;
- }
-
- /**
- * Return the same value as {@link Boolean#hashCode()}.
- * @see Boolean#hashCode()
- */
- public static int hashCode(boolean bool) {
- return bool ? 1231 : 1237;
- }
-
- /**
- * Return the same value as {@link Double#hashCode()}.
- * @see Double#hashCode()
- */
- public static int hashCode(double dbl) {
- long bits = Double.doubleToLongBits(dbl);
- return hashCode(bits);
- }
-
- /**
- * Return the same value as {@link Float#hashCode()}.
- * @see Float#hashCode()
- */
- public static int hashCode(float flt) {
- return Float.floatToIntBits(flt);
- }
-
- /**
- * Return the same value as {@link Long#hashCode()}.
- * @see Long#hashCode()
- */
- public static int hashCode(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 null)
- * @return the object's identity as String representation,
- * or an empty String if the object was null
- */
- public static String identityToString(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(Object obj) {
- return Integer.toHexString(System.identityHashCode(obj));
- }
-
- /**
- * Return a content-based String representation if obj is
- * not null; otherwise returns an empty String.
- *
Differs from {@link #nullSafeToString(Object)} in that it returns
- * an empty String rather than "null" for a null value.
- * @param obj the object to build a display String for
- * @return a display String representation of obj
- * @see #nullSafeToString(Object)
- */
- public static String getDisplayString(Object obj) {
- if (obj == null) {
- return EMPTY_STRING;
- }
- return nullSafeToString(obj);
- }
-
- /**
- * Determine the class name for the given object.
- *
Returns "null" if obj is null.
- * @param obj the object to introspect (may be null)
- * @return the corresponding class name
- */
- public static String nullSafeClassName(Object obj) {
- return (obj != null ? obj.getClass().getName() : NULL_STRING);
- }
-
- /**
- * Return a String representation of the specified Object.
- *
Builds a String representation of the contents in case of an array.
- * Returns "null" if obj is null.
- * @param obj the object to build a String representation for
- * @return a String representation of obj
- */
- public static String nullSafeToString(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);
- }
- String str = obj.toString();
- return (str != null ? str : EMPTY_STRING);
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(Object[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append(String.valueOf(array[i]));
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(boolean[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
-
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(byte[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(char[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append("'").append(array[i]).append("'");
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(double[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
-
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(float[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
-
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(int[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(long[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
- /**
- * Return a String representation of the contents of the specified array.
- *
The String representation consists of a list of the array's elements,
- * enclosed in curly braces ("{}"). Adjacent elements are separated
- * by the characters ", " (a comma followed by a space). Returns
- * "null" if array is null.
- * @param array the array to build a String representation for
- * @return a String representation of array
- */
- public static String nullSafeToString(short[] array) {
- if (array == null) {
- return NULL_STRING;
- }
- int length = array.length;
- if (length == 0) {
- return EMPTY_ARRAY;
- }
- StringBuffer buffer = new StringBuffer();
- for (int i = 0; i < length; i++) {
- if (i == 0) {
- buffer.append(ARRAY_START);
- }
- else {
- buffer.append(ARRAY_ELEMENT_SEPARATOR);
- }
- buffer.append(array[i]);
- }
- buffer.append(ARRAY_END);
- return buffer.toString();
- }
-
-}