System.arraycopy( src, src_position, dst, dst_position, length);
}
-
+ /**
+ * Moves a number of entries in an array to another point in the array,
+ * shifting those inbetween as required.
+ * @param array The array to alter
+ * @param moveFrom The (0 based) index of the first entry to move
+ * @param moveTo The (0 based) index of the positition to move to
+ * @param numToMove The number of entries to move
+ */
+ public static void arrayMoveWithin(Object[] array, int moveFrom, int moveTo, int numToMove) {
+ // If we're not asked to do anything, return now
+ if(numToMove <= 0) { return; }
+ if(moveFrom == moveTo) { return; }
+
+ // Check that the values supplied are valid
+ if(moveFrom < 0 || moveFrom >= array.length) {
+ throw new IllegalArgumentException("The moveFrom must be a valid array index");
+ }
+ if(moveTo < 0 || moveTo >= array.length) {
+ throw new IllegalArgumentException("The moveTo must be a valid array index");
+ }
+ if(moveFrom+numToMove > array.length) {
+ throw new IllegalArgumentException("Asked to move more entries than the array has");
+ }
+ if(moveTo+numToMove > array.length) {
+ throw new IllegalArgumentException("Asked to move to a position that doesn't have enough space");
+ }
+
+ // Grab the bit to move
+ Object[] toMove = new Object[numToMove];
+ System.arraycopy(array, moveFrom, toMove, 0, numToMove);
+
+ // Grab the bit to be shifted
+ Object[] toShift;
+ int shiftTo;
+ if(moveFrom > moveTo) {
+ // Moving to an earlier point in the array
+ // Grab everything between the two points
+ toShift = new Object[(moveFrom-moveTo)];
+ System.arraycopy(array, moveTo, toShift, 0, toShift.length);
+ shiftTo = moveTo + numToMove;
+ } else {
+ // Moving to a later point in the array
+ // Grab everything from after the toMove block, to the new point
+ toShift = new Object[(moveTo-moveFrom)];
+ System.arraycopy(array, moveFrom+numToMove, toShift, 0, toShift.length);
+ shiftTo = moveFrom;
+ }
+
+ // Copy the moved block to its new location
+ System.arraycopy(toMove, 0, array, moveTo, toMove.length);
+
+ // And copy the shifted block to the shifted location
+ System.arraycopy(toShift, 0, array, shiftTo, toShift.length);
+
+
+ // We're done - array will now have everything moved as required
+ }
}
--- /dev/null
+
+/* ====================================================================
+ Copyright 2002-2004 Apache Software Foundation
+
+ Licensed 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.poi.util;
+
+import junit.framework.*;
+
+/**
+ * Unit test for ArrayUtil
+ *
+ * @author Nick Burch
+ */
+public class TestArrayUtil extends TestCase
+{
+ /**
+ * Test to ensure that our own arraycopy behaves as it should do
+ */
+ public void testarraycopy() {
+ byte[] bytes = new byte[] { 0x01, 0x02, 0x03, 0x04 };
+
+ // Test copy whole thing
+ byte[] dest = new byte[4];
+ ArrayUtil.arraycopy(bytes, 0, dest, 0, 4);
+
+ assertEquals(dest.length, bytes.length);
+ for(int i=0; i<dest.length; i++) {
+ assertEquals(bytes[i], dest[i]);
+ }
+
+ // ToDo - test exceptions are as expected
+ }
+
+
+ /**
+ * Helper for testArrayMoveWithin
+ */
+ private Integer[] getIntsList() {
+ return new Integer[] {
+ new Integer(0),
+ new Integer(1),
+ new Integer(2),
+ new Integer(3),
+ new Integer(4),
+ new Integer(5),
+ new Integer(6),
+ new Integer(7),
+ new Integer(8),
+ new Integer(9)
+ };
+ }
+
+ /**
+ * Test to ensure that arrayMoveWithin works as expected
+ */
+ public void testArrayMoveWithin() {
+ Integer[] ints = getIntsList();
+
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(2), ints[2]);
+ assertEquals(new Integer(3), ints[3]);
+ assertEquals(new Integer(4), ints[4]);
+ assertEquals(new Integer(5), ints[5]);
+ assertEquals(new Integer(6), ints[6]);
+ assertEquals(new Integer(7), ints[7]);
+ assertEquals(new Integer(8), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+
+ //
+ // Moving to a later point in the array
+ //
+
+ // Shift 1 back
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 4, 8, 1);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(2), ints[2]);
+ assertEquals(new Integer(3), ints[3]);
+ assertEquals(new Integer(5), ints[4]);
+ assertEquals(new Integer(6), ints[5]);
+ assertEquals(new Integer(7), ints[6]);
+ assertEquals(new Integer(8), ints[7]);
+ assertEquals(new Integer(4), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift front 1 back
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 0, 7, 1);
+ assertEquals(new Integer(1), ints[0]);
+ assertEquals(new Integer(2), ints[1]);
+ assertEquals(new Integer(3), ints[2]);
+ assertEquals(new Integer(4), ints[3]);
+ assertEquals(new Integer(5), ints[4]);
+ assertEquals(new Integer(6), ints[5]);
+ assertEquals(new Integer(7), ints[6]);
+ assertEquals(new Integer(0), ints[7]);
+ assertEquals(new Integer(8), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift 1 to end
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 4, 9, 1);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(2), ints[2]);
+ assertEquals(new Integer(3), ints[3]);
+ assertEquals(new Integer(5), ints[4]);
+ assertEquals(new Integer(6), ints[5]);
+ assertEquals(new Integer(7), ints[6]);
+ assertEquals(new Integer(8), ints[7]);
+ assertEquals(new Integer(9), ints[8]);
+ assertEquals(new Integer(4), ints[9]);
+
+
+ //
+ // Moving to an earlier point in the array
+ //
+
+ // Shift 1 forward
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 8, 3, 1);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(2), ints[2]);
+ assertEquals(new Integer(8), ints[3]);
+ assertEquals(new Integer(3), ints[4]);
+ assertEquals(new Integer(4), ints[5]);
+ assertEquals(new Integer(5), ints[6]);
+ assertEquals(new Integer(6), ints[7]);
+ assertEquals(new Integer(7), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift end 1 forward
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 9, 2, 1);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(9), ints[2]);
+ assertEquals(new Integer(2), ints[3]);
+ assertEquals(new Integer(3), ints[4]);
+ assertEquals(new Integer(4), ints[5]);
+ assertEquals(new Integer(5), ints[6]);
+ assertEquals(new Integer(6), ints[7]);
+ assertEquals(new Integer(7), ints[8]);
+ assertEquals(new Integer(8), ints[9]);
+
+ // Shift 1 to front
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 5, 0, 1);
+ assertEquals(new Integer(5), ints[0]);
+ assertEquals(new Integer(0), ints[1]);
+ assertEquals(new Integer(1), ints[2]);
+ assertEquals(new Integer(2), ints[3]);
+ assertEquals(new Integer(3), ints[4]);
+ assertEquals(new Integer(4), ints[5]);
+ assertEquals(new Integer(6), ints[6]);
+ assertEquals(new Integer(7), ints[7]);
+ assertEquals(new Integer(8), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+
+ //
+ // Moving many to a later point in the array
+ //
+
+ // Shift 3 back
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 2, 6, 3);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(5), ints[2]);
+ assertEquals(new Integer(6), ints[3]);
+ assertEquals(new Integer(7), ints[4]);
+ assertEquals(new Integer(8), ints[5]);
+ assertEquals(new Integer(2), ints[6]);
+ assertEquals(new Integer(3), ints[7]);
+ assertEquals(new Integer(4), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift 3 to back
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 2, 7, 3);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(5), ints[2]);
+ assertEquals(new Integer(6), ints[3]);
+ assertEquals(new Integer(7), ints[4]);
+ assertEquals(new Integer(8), ints[5]);
+ assertEquals(new Integer(9), ints[6]);
+ assertEquals(new Integer(2), ints[7]);
+ assertEquals(new Integer(3), ints[8]);
+ assertEquals(new Integer(4), ints[9]);
+
+ // Shift from 3 front
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 0, 5, 3);
+ assertEquals(new Integer(3), ints[0]);
+ assertEquals(new Integer(4), ints[1]);
+ assertEquals(new Integer(5), ints[2]);
+ assertEquals(new Integer(6), ints[3]);
+ assertEquals(new Integer(7), ints[4]);
+ assertEquals(new Integer(0), ints[5]);
+ assertEquals(new Integer(1), ints[6]);
+ assertEquals(new Integer(2), ints[7]);
+ assertEquals(new Integer(8), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+
+ //
+ // Moving many to an earlier point in the array
+ //
+
+ // Shift 3 forward
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 6, 2, 3);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(6), ints[2]);
+ assertEquals(new Integer(7), ints[3]);
+ assertEquals(new Integer(8), ints[4]);
+ assertEquals(new Integer(2), ints[5]);
+ assertEquals(new Integer(3), ints[6]);
+ assertEquals(new Integer(4), ints[7]);
+ assertEquals(new Integer(5), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift 3 to front
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 6, 0, 3);
+ assertEquals(new Integer(6), ints[0]);
+ assertEquals(new Integer(7), ints[1]);
+ assertEquals(new Integer(8), ints[2]);
+ assertEquals(new Integer(0), ints[3]);
+ assertEquals(new Integer(1), ints[4]);
+ assertEquals(new Integer(2), ints[5]);
+ assertEquals(new Integer(3), ints[6]);
+ assertEquals(new Integer(4), ints[7]);
+ assertEquals(new Integer(5), ints[8]);
+ assertEquals(new Integer(9), ints[9]);
+
+ // Shift from 3 back
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 7, 3, 3);
+ assertEquals(new Integer(0), ints[0]);
+ assertEquals(new Integer(1), ints[1]);
+ assertEquals(new Integer(2), ints[2]);
+ assertEquals(new Integer(7), ints[3]);
+ assertEquals(new Integer(8), ints[4]);
+ assertEquals(new Integer(9), ints[5]);
+ assertEquals(new Integer(3), ints[6]);
+ assertEquals(new Integer(4), ints[7]);
+ assertEquals(new Integer(5), ints[8]);
+ assertEquals(new Integer(6), ints[9]);
+
+
+ // Check can't shift more than we have
+ try {
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 7, 3, 5);
+ fail();
+ } catch(IllegalArgumentException e) {
+ // Good, we don't have 5 from 7 onwards
+ }
+
+ // Check can't shift where would overshoot
+ try {
+ ints = getIntsList();
+ ArrayUtil.arrayMoveWithin(ints, 2, 7, 5);
+ fail();
+ } catch(IllegalArgumentException e) {
+ // Good, we can't fit 5 in starting at 7
+ }
+ }
+}
+
projects / poi.git / commitdiff