用LinkedHashMap public static void main(String[] args) { Map<Character, Integer> map = new LinkedHashMap<Character, Integer>(); for (int i = 26; i > 0; i--) { map.put((char)(97+i-1), i); } System.out.println(map.keySet()); System.out.println(map.values()); }
当然可以了,TreeMap就支持逆序排列,不过默认是按照自然顺序的,需要自己实现Comparator,见下面的代码: package learning;import java.util.Comparator; import java.util.Map; import java.util.TreeMap;public class SortedMapTest { public static class ReverseComp implements Comparator<Character>{ @Override public int compare(Character o1, Character o2) { return o2.compareTo(o1); }
} public static void main(String[] args) {
Map<Character, Integer> orderMap = new TreeMap<Character, Integer>(); for(int i = 0; i < 26; i++) orderMap.put((char)(97 + i), (i + 1)); System.out.println(orderMap);
Map<Character, Integer> reverseMap = new TreeMap<Character, Integer>(new ReverseComp()); for(int i = 0; i < 26; i++) reverseMap.put((char)(97 + i), (i + 1)); System.out.println(reverseMap);
public static void main(String[] args) {
Map<Character, Integer> map = new LinkedHashMap<Character, Integer>();
for (int i = 26; i > 0; i--) {
map.put((char)(97+i-1), i);
}
System.out.println(map.keySet());
System.out.println(map.values());
}
package learning;import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;public class SortedMapTest {
public static class ReverseComp implements Comparator<Character>{ @Override
public int compare(Character o1, Character o2) {
return o2.compareTo(o1);
}
}
public static void main(String[] args) {
Map<Character, Integer> orderMap = new TreeMap<Character, Integer>();
for(int i = 0; i < 26; i++)
orderMap.put((char)(97 + i), (i + 1));
System.out.println(orderMap);
Map<Character, Integer> reverseMap = new TreeMap<Character, Integer>(new ReverseComp());
for(int i = 0; i < 26; i++)
reverseMap.put((char)(97 + i), (i + 1));
System.out.println(reverseMap);
}}
输出为:{a=1, b=2, c=3, d=4, e=5, f=6, g=7, h=8, i=9, j=10, k=11, l=12, m=13, n=14, o=15, p=16, q=17, r=18, s=19, t=20, u=21, v=22, w=23, x=24, y=25, z=26}
{z=26, y=25, x=24, w=23, v=22, u=21, t=20, s=19, r=18, q=17, p=16, o=15, n=14, m=13, l=12, k=11, j=10, i=9, h=8, g=7, f=6, e=5, d=4, c=3, b=2, a=1}