java里的字母逆序排序

public class io{
static String desc(String str){
char[] cha = str.toCharArray();
for(int i = 0; i<cha.length ; i++){
for(int j = i + 1; j<cha.length ; j++){
if((int)cha[i] < (int)cha[j]){
int tem = cha[i];
cha[i] = cha[j];
cha[j] = (char)tem;
}
}
}
return new String(cha);
}
public static void main(String[] args){
System.out.println(desc("acubep"));
}
}

reverse这个方法一步可以倒过来

public String reverse(String input)
{
StringBuffer strBuffer = new StringBuffer();
if(input != null && !input.equals(""))
{
strBuffer = new StringBuffer(input);
}
return strBuffer.reverse();
}

public static void main(String[] args)
{
String str = "acubep