Returns the length of the specified array.
+ * This method can deal with Object arrays and with primitive arrays.
If the input array is null, 0 is returned.
+ * ArrayUtils.getLength(null) = 0 + * ArrayUtils.getLength([]) = 0 + * ArrayUtils.getLength([null]) = 1 + * ArrayUtils.getLength([true, false]) = 2 + * ArrayUtils.getLength([1, 2, 3]) = 3 + * ArrayUtils.getLength(["a", "b", "c"]) = 3 + *+ * + * @param array the array to retrieve the length from, may be null + * @return The length of the array, or
0 if the array is null
+ * @throws IllegalArgumentException if the object arguement is not an array.
+ */
+ public static int getLength(final Object array) {
+ if (array == null) {
+ return 0;
+ } else {
+ return Array.getLength(array);
+ }
+ }
+
+ /**
+ * Returns the last index of the given array or -1 if empty or null.
+ * This method can deal with Object arrays and with primitive arrays.
+ * This value is one less than the size since arrays indices are 0-based.
+ *
+ * + * ArrayUtils.lastIndex(null) = -1 + * ArrayUtils.lastIndex([]) = -1 + * ArrayUtils.lastIndex([null]) = 0 + * ArrayUtils.lastIndex([true, false]) = 1 + * ArrayUtils.lastIndex([1, 2, 3]) = 2 + * ArrayUtils.lastIndex(["a", "b", "c"]) = 2 + *+ * + * @param array the array to return the last index for, may be null + * @return the last index, -1 if empty or null + * @throws IllegalArgumentException if the object arguement is not an array. + */ + public static int lastIndex(final Object array) { + return ArrayUtils.getLength(array) - 1; + } + /** *
Checks whether two arrays are the same type taking into account * multi-dimensional arrays.
@@ -3051,17 +3102,6 @@ public class ArrayUtils { } } - /** - * Returns the last index of the given array. This value is one less than the size since - * arrays indices are 0-based. - * - * @param array The array to return the last index for, must not benull.
- * @return The last index
- */
- public static int lastIndex(final Object array) {
- return Array.getLength(array) - 1;
- }
-
/**
* Inserts the specified element at the specified position in the array. * Shifts the element currently at that position (if any) and any subsequent @@ -3111,4 +3151,5 @@ public class ArrayUtils { } return (Object[]) result; } + } diff --git a/src/test/org/apache/commons/lang/ArrayUtilsTest.java b/src/test/org/apache/commons/lang/ArrayUtilsTest.java index 7f383d1ad..4c37416f5 100644 --- a/src/test/org/apache/commons/lang/ArrayUtilsTest.java +++ b/src/test/org/apache/commons/lang/ArrayUtilsTest.java @@ -75,7 +75,8 @@ import junit.textui.TestRunner; * @author Ashwin S * @author Fredrik Westermarck * @author Gary Gregory - * @version $Id: ArrayUtilsTest.java,v 1.24 2004/02/03 22:14:24 ggregory Exp $ + * @author Maarten Coene + * @version $Id: ArrayUtilsTest.java,v 1.25 2004/02/14 01:15:20 scolebourne Exp $ */ public class ArrayUtilsTest extends TestCase { @@ -2362,4 +2363,120 @@ public class ArrayUtilsTest extends TestCase { assertEquals(true, ArrayUtils.isEmpty(emptyBooleanArray)); assertEquals(false, ArrayUtils.isEmpty(notEmptyBooleanArray)); } + + // ------------------------------------------------------------------------ + public void testGetLength() { + assertEquals(0, ArrayUtils.getLength(null)); + + Object[] emptyObjectArray = new Object[0]; + Object[] notEmptyObjectArray = new Object[] {"aValue"}; + assertEquals(0, ArrayUtils.getLength((Object[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyObjectArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyObjectArray)); + + int[] emptyIntArray = new int[] {}; + int[] notEmptyIntArray = new int[] { 1 }; + assertEquals(0, ArrayUtils.getLength((int[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyIntArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyIntArray)); + + short[] emptyShortArray = new short[] {}; + short[] notEmptyShortArray = new short[] { 1 }; + assertEquals(0, ArrayUtils.getLength((short[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyShortArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyShortArray)); + + char[] emptyCharArray = new char[] {}; + char[] notEmptyCharArray = new char[] { 1 }; + assertEquals(0, ArrayUtils.getLength((char[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyCharArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyCharArray)); + + byte[] emptyByteArray = new byte[] {}; + byte[] notEmptyByteArray = new byte[] { 1 }; + assertEquals(0, ArrayUtils.getLength((byte[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyByteArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyByteArray)); + + double[] emptyDoubleArray = new double[] {}; + double[] notEmptyDoubleArray = new double[] { 1.0 }; + assertEquals(0, ArrayUtils.getLength((double[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyDoubleArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyDoubleArray)); + + float[] emptyFloatArray = new float[] {}; + float[] notEmptyFloatArray = new float[] { 1.0F }; + assertEquals(0, ArrayUtils.getLength((float[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyFloatArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyFloatArray)); + + boolean[] emptyBooleanArray = new boolean[] {}; + boolean[] notEmptyBooleanArray = new boolean[] { true }; + assertEquals(0, ArrayUtils.getLength((boolean[]) null)); + assertEquals(0, ArrayUtils.getLength(emptyBooleanArray)); + assertEquals(1, ArrayUtils.getLength(notEmptyBooleanArray)); + + try { + ArrayUtils.getLength("notAnArray"); + fail("IllegalArgumentException should have been thrown"); + } catch (IllegalArgumentException e) {} + } + + public void testLastIndex() { + assertEquals(-1, ArrayUtils.lastIndex(null)); + + Object[] emptyObjectArray = new Object[0]; + Object[] notEmptyObjectArray = new Object[] {"aValue"}; + assertEquals(-1, ArrayUtils.lastIndex((Object[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyObjectArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyObjectArray)); + + int[] emptyIntArray = new int[] {}; + int[] notEmptyIntArray = new int[] { 1 }; + assertEquals(-1, ArrayUtils.lastIndex((int[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyIntArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyIntArray)); + + short[] emptyShortArray = new short[] {}; + short[] notEmptyShortArray = new short[] { 1 }; + assertEquals(-1, ArrayUtils.lastIndex((short[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyShortArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyShortArray)); + + char[] emptyCharArray = new char[] {}; + char[] notEmptyCharArray = new char[] { 1 }; + assertEquals(-1, ArrayUtils.lastIndex((char[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyCharArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyCharArray)); + + byte[] emptyByteArray = new byte[] {}; + byte[] notEmptyByteArray = new byte[] { 1 }; + assertEquals(-1, ArrayUtils.lastIndex((byte[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyByteArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyByteArray)); + + double[] emptyDoubleArray = new double[] {}; + double[] notEmptyDoubleArray = new double[] { 1.0 }; + assertEquals(-1, ArrayUtils.lastIndex((double[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyDoubleArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyDoubleArray)); + + float[] emptyFloatArray = new float[] {}; + float[] notEmptyFloatArray = new float[] { 1.0F }; + assertEquals(-1, ArrayUtils.lastIndex((float[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyFloatArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyFloatArray)); + + boolean[] emptyBooleanArray = new boolean[] {}; + boolean[] notEmptyBooleanArray = new boolean[] { true }; + assertEquals(-1, ArrayUtils.lastIndex((boolean[]) null)); + assertEquals(-1, ArrayUtils.lastIndex(emptyBooleanArray)); + assertEquals(0, ArrayUtils.lastIndex(notEmptyBooleanArray)); + + try { + ArrayUtils.lastIndex("notAnArray"); + fail("IllegalArgumentException should have been thrown"); + } catch (IllegalArgumentException e) {} + } + }