Java. util. collections collection help class example Program (JUnit demo) sorting @ TestpublicvoidtestSort () {ListIntegerdemoListnewArrayListInteger (Arrays. asList (3, 2, 1); assertEquals (3, demoList. get (0 ). intValue (); publicstaticTextendsComparable
Java. util. collections collection help class example Program (JUnit demo) sorting @ Test public void testSort () {ListInteger demoList = new ArrayListInteger (Arrays. asList (3, 2, 1); assertEquals (3, demoList. get (0 ). intValue (); // public static T extends Comparable
Java. util. Collections collection help class example Program (JUnit demo) sorting
@ Test public void testSort () {List
DemoList = new ArrayList
(Arrays. asList (3, 2, 1); assertEquals (3, demoList. get (0). intValue (); // public static
> Void sort (List
List) Collections. sort (demoList); assertEquals (1, demoList. get (0). intValue (); // public static void shuffle (List
List) // random sorting // public static void reverse (List
List) // Reverse Order}
Search@ Test public void testBinarySearch () {List
DemoList = new ArrayList
(Arrays. asList (3, 2, 1); // you must first sort Collections. sort (demoList); assertEquals (1, demoList. get (0 ). intValue (); // Binary Search location // public static
Int binarySearch (List
> List, T key) assertEquals (0, Collections. binarySearch (demoList, 1); // public static int indexOfSubList (List
Source, List
Target) // public static int lastIndexOfSubList (List
Source, List
Target )}
Replacement@ Test public void testSwap () {List
DemoList = new ArrayList
(Arrays. asList (3, 2, 1); // public static void swap (List
List, int I, int j) Collections. swap (demoList, 0, 2); assertEquals (1, demoList. get (0 ). intValue (); // public static void rotate (List
List, int distance) // specify the distance rotation // public static
Boolean replaceAll (List
List, T oldVal, T newVal) // specifies the replacement}
Copy@ Test public void testCopy () {List
DemoList = new ArrayList
(Arrays. asList (3, 2, 1); // public static
Void copy (List
Dest, List
Src) // note that the size of the destination List must be equal to the size List of src at least.
CopyList = new ArrayList
(Arrays. asList (1, 2, 3); Collections. copy (copyList, demoList); assertEquals (3, copyList. size (); assertEquals (3, copyList. get (0 ). intValue (); copyList. add (4); assertEquals (3, demoList. size ());}
Comparison @Test public void testCompary() { List
demoList = new ArrayList
(Arrays.asList(3, 2, 1)); assertEquals(1, Collections.min(demoList).intValue()); assertEquals(3, Collections.max(demoList).intValue()); List
compareList = new ArrayList
(Arrays.asList(5, 6, 7)); //Returns true if the two specified collections have no elements in common assertTrue(Collections.disjoint(demoList, compareList)); }
Create different sets@ SuppressWarnings ("unused") @ Test public void testCreate () {List
DemoList = new ArrayList
(Arrays. asList (3, 2, 1); // empty object size = 0 No add method List
EmptyList = Collections. emptyList (); // returns an unchangeable list containing only the specified object. List
SingletonList = Collections. singletonList (1); // return a dynamic security view of the specified list. List
CheckedList = Collections. checkedList (demoList, Integer. class); // return the unchangeable view of the specified list. List
UnmodifiableList = Collections. unmodifiableList (demoList); // return the synchronization (thread-safe) List supported by the specified list. List
SynchronizedList = Collections. synchronizedList (demoList); synchronized (synchronizedList) {Iterator
I = synchronizedList. iterator (); // Must be in synchronized block while (I. hasNext () I. next ();} // map set sortedMap sortedSet}
Environment jdk1.6 window7 junit4