如何将排序结构与字符串合并？

import java.util.Arrays;

public class StringMergeSort {
    public static void main(String[] args) {
        String inputString = "hello world";
        char[] charArray = inputString.toCharArray();
        
        // 使用快速排序算法对字符数组进行排序
        quickSort(charArray, 0, charArray.length - 1);
        
        // 将排序后的字符数组重新组合成字符串
        String sortedString = new String(charArray);
        
        System.out.println("排序后的字符串：" + sortedString);
    }
    
    public static void quickSort(char[] arr, int low, int high) {
        if (low < high) {
            int pivotIndex = partition(arr, low, high);
            quickSort(arr, low, pivotIndex - 1);
            quickSort(arr, pivotIndex + 1, high);
        }
    }
    
    public static int partition(char[] arr, int low, int high) {
        char pivot = arr[high];
        int i = low - 1;
        
        for (int j = low; j < high; j++) {
            if (arr[j] < pivot) {
                i++;
                swap(arr, i, j);
            }
        }
        
        swap(arr, i + 1, high);
        return i + 1;
    }
    
    public static void swap(char[] arr, int i, int j) {
        char temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
}