1 import org.junit.Test; 2  3 public class AllSort { 4  5     public void permutation(char[] buf, int start, int end) { 6         if (start == end) {// 当只要求对数组中一个字母进行全排列时，只要就按该数组输出即可 7             for (int i = 0; i <= end; i++) { 8                 System.out.print(buf[i]); 9             }10             System.out.println();11         } else {// 多个字母全排列12             for (int i = start; i <= end; i++) {13                 char temp = buf[start];// 交换数组第一个元素与后续的元素14                 buf[start] = buf[i];15                 buf[i] = temp;16 17                 permutation(buf, start + 1, end);// 后续元素递归全排列18 19                 temp = buf[start];// 将交换后的数组还原20                 buf[start] = buf[i];21                 buf[i] = temp;22             }23         }24     }25 26     @Test27     public void testPermutation() throws Exception {28         char[] buf = new char[] { ‘a‘, ‘b‘, ‘c‘ };29         permutation(buf, 0, 2);30     }31 }