java怎么实现字符串中的字母排序

String str = "chenughonghuiaikuangwantong1314";
    char[] chars = str.toCharArray();

static void sort(type [] a)

static void sort(type [] a, int fromIndex, int toIndex)

for (int i = 0; i < chars.length; i++) {
        System.out.print(chars[i]);
    }

for (int i = chars.length - 1; i >= 0; i--) {
        System.out.print(chars[i]);
    }

import java.util.Arrays;

public class characterSorting {
    public static void main(String[] args) {
        String str = "chenughonghuiaikuangwantong1314";
        System.out.println("原字符串："+str);
        char[] chars = str.toCharArray();
        Arrays.sort(chars);
        //正序遍历输出
        System.out.println("正序输出：");
        for (int i = 0; i < chars.length; i++) {
            System.out.print(chars[i]);
        }
        //倒序遍历输出
        System.out.println();
        System.out.println("倒序输出：");
        for (int i = chars.length - 1; i >= 0; i--) {
            System.out.print(chars[i]);
        }
    }
}