headMap(K toKey, boolean inclusive)
NavigableMap<K,V> headMap(K toKey, boolean inclusive)- Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey.
import java.util.TreeMap;
public class Main {
public static void main(String[] a) {
TreeMap<String,String> map = new TreeMap<String,String>();
map.put("key1", "value1");
map.put("key2", "value2");
map.put("key3", "value3");
if (!map.isEmpty()) {
String last = map.lastKey();
boolean first = true;
do {
if (!first) {
System.out.print(", ");
}
System.out.print(last);
last = map.headMap(last, true).lastKey();
first = false;
} while (last != map.firstKey());
System.out.println();
}
}
}