org.apache.commons.lang3.ArrayUtils#swap ( )源码实例Demo

@Test
public void testRemoveRandomly() {
	final int COUNT = 100;
	Random rand = new Random();
	DynamicValueSortedTreeMap<String, Integer> queue = new DynamicValueSortedTreeMap<>();
	HashSet<String> all = new HashSet<>();
	for (int i = 0; i < COUNT; i++) {
		queue.put("Element" + i, rand.nextInt(50));
		all.add("Element" + i);
	}
	checkConsistent(queue);

	String[] shuffled = all.toArray(new String[all.size()]);
	for (int i = 0; i < shuffled.length; i++) {
		ArrayUtils.swap(shuffled, i, i + rand.nextInt(shuffled.length - i));
	}
	for (String s : shuffled) {
		queue.remove(s);
		checkConsistent(queue);
	}
	assertTrue(queue.isEmpty());
	assertTrue(queue.size() == 0);
}
 

private void insertMenuEntry(MenuEntry newEntry, MenuEntry[] entries, boolean after)
{
	MenuEntry[] newMenu = ObjectArrays.concat(entries, newEntry);

	if (after)
	{
		int menuEntryCount = newMenu.length;
		ArrayUtils.swap(newMenu, menuEntryCount - 1, menuEntryCount - 2);
	}

	client.setMenuEntries(newMenu);
}
 

private void insertMenuEntry(MenuEntry newEntry, MenuEntry[] entries)
{
	MenuEntry[] newMenu = ObjectArrays.concat(entries, newEntry);
	int menuEntryCount = newMenu.length;
	ArrayUtils.swap(newMenu, menuEntryCount - 1, menuEntryCount - 2);
	if (client != null)
	{
		client.setMenuEntries(newMenu);
	}
}
 

@Test
public void testValueIndices() {
	final int ROUNDS = 1000;
	Random rand = new Random();
	DynamicValueSortedTreeMap<String, Integer> queue = new DynamicValueSortedTreeMap<>();
	int[] vals = // 0  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17 18 19 20 21 22
		new int[] { 0, 0, 1, 1, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 8, 8, 10 };
	for (int r = 0; r < ROUNDS; r++) {
		for (int i = 0; i < vals.length; i++) {
			ArrayUtils.swap(vals, i, i + rand.nextInt(vals.length - i));
		}
		for (int i = 0; i < vals.length; i++) {
			queue.put("Element" + i, vals[i]);
		}
		checkConsistent(queue);
		assertEquals(0, queue.values().indexOf(0));
		assertEquals(1, queue.values().lastIndexOf(0));
		assertEquals(2, queue.values().indexOf(1));
		assertEquals(4, queue.values().lastIndexOf(1));
		assertEquals(5, queue.values().indexOf(2));
		assertEquals(5, queue.values().lastIndexOf(2));
		assertEquals(6, queue.values().indexOf(3));
		assertEquals(6, queue.values().lastIndexOf(3));
		assertEquals(7, queue.values().indexOf(4));
		assertEquals(8, queue.values().lastIndexOf(4));
		assertEquals(9, queue.values().indexOf(5));
		assertEquals(10, queue.values().lastIndexOf(5));
		assertEquals(11, queue.values().indexOf(6));
		assertEquals(19, queue.values().lastIndexOf(6));
		assertEquals(-1, queue.values().indexOf(7));
		assertEquals(-1, queue.values().lastIndexOf(7));
		assertEquals(20, queue.values().indexOf(8));
		assertEquals(21, queue.values().lastIndexOf(8));
		assertEquals(-1, queue.values().indexOf(9));
		assertEquals(-1, queue.values().lastIndexOf(9));
		assertEquals(22, queue.values().indexOf(10));
		assertEquals(22, queue.values().lastIndexOf(10));
	}
}
 

private void insertMenuEntry(MenuEntry newEntry, MenuEntry[] entries)
{
	MenuEntry[] newMenu = ObjectArrays.concat(entries, newEntry);
	int menuEntryCount = newMenu.length;
	ArrayUtils.swap(newMenu, menuEntryCount - 1, menuEntryCount - 2);
	client.setMenuEntries(newMenu);
}
 

private void insertMenuEntry(MenuEntry newEntry, MenuEntry[] entries, boolean after)
{
	MenuEntry[] newMenu = ObjectArrays.concat(entries, newEntry);

	if (after)
	{
		int menuEntryCount = newMenu.length;
		ArrayUtils.swap(newMenu, menuEntryCount - 1, menuEntryCount - 2);
	}

	client.setMenuEntries(newMenu);
}
 

@Test
public void givenArray_whenSwapingElementsWithinARange_thenCorrect() {
    int[] originalArray = { 1, 2, 3, 4, 5 };
    ArrayUtils.swap(originalArray, 0, 3, 2);
    int[] expectedArray = { 4, 5, 3, 1, 2 };
    assertArrayEquals(expectedArray, originalArray);
}
 

@Test
public void givenArray_whenSwapingElementsAtSpecifiedPositions_thenCorrect() {
    int[] originalArray = { 1, 2, 3, 4, 5 };
    ArrayUtils.swap(originalArray, 0, 3);
    int[] expectedArray = { 4, 2, 3, 1, 5 };
    assertArrayEquals(expectedArray, originalArray);
}