| 1 |
dl |
1.2 |
/* |
| 2 |
|
|
* Written by Doug Lea with assistance from members of JCP JSR-166 |
| 3 |
|
|
* Expert Group and released to the public domain, as explained at |
| 4 |
jsr166 |
1.4 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
| 5 |
dl |
1.2 |
*/ |
| 6 |
|
|
|
| 7 |
|
|
// Adapted from bug report 5018354 |
| 8 |
dl |
1.1 |
import java.util.*; |
| 9 |
|
|
|
| 10 |
|
|
public class LastKeyOfSubMap { |
| 11 |
|
|
private static final Comparator NULL_AT_END = new Comparator() { |
| 12 |
|
|
/** |
| 13 |
|
|
* Allows for nulls. Null is greater than anything non-null. |
| 14 |
|
|
*/ |
| 15 |
|
|
public int compare(Object pObj1, Object pObj2) { |
| 16 |
|
|
if (pObj1 == null && pObj2 == null) return 0; |
| 17 |
|
|
if (pObj1 == null && pObj2 != null) return 1; |
| 18 |
|
|
if (pObj1 != null && pObj2 == null) return -1; |
| 19 |
|
|
return ((Comparable) pObj1).compareTo(pObj2); |
| 20 |
|
|
} |
| 21 |
jsr166 |
1.3 |
}; |
| 22 |
dl |
1.1 |
|
| 23 |
|
|
public static void main(String[] pArgs) { |
| 24 |
|
|
SortedMap m1 = new TreeMap(NULL_AT_END); |
| 25 |
|
|
m1.put("a", "a"); |
| 26 |
|
|
m1.put("b", "b"); |
| 27 |
|
|
m1.put("c", "c"); |
| 28 |
|
|
m1.put(null, "d"); |
| 29 |
|
|
|
| 30 |
|
|
SortedMap m2 = new TreeMap(m1); |
| 31 |
|
|
|
| 32 |
|
|
System.out.println(m1.lastKey()); |
| 33 |
|
|
System.out.println(m1.get(m1.lastKey())); |
| 34 |
|
|
Object m1lk = m1.remove(m1.lastKey()); |
| 35 |
|
|
if (m1lk == null) |
| 36 |
|
|
throw new Error("bad remove of last key"); |
| 37 |
|
|
|
| 38 |
|
|
m2 = m2.tailMap("b"); |
| 39 |
|
|
|
| 40 |
|
|
System.out.println(m2.lastKey()); |
| 41 |
|
|
System.out.println(m2.get(m2.lastKey())); |
| 42 |
|
|
Object m2lk = m2.remove(m2.lastKey()); |
| 43 |
|
|
if (m2lk == null) |
| 44 |
|
|
throw new Error("bad remove of last key"); |
| 45 |
|
|
} |
| 46 |
|
|
} |
