import java.util.Arrays;

import java.util.Scanner;

public class Test4{

       public static void main(String[] args){

                    Scanner in=new Scanner(System.in);

                    System.out.println("请输入总数");

                    int num=in.nextInt();

                     int[] arr=new int[num];

                    for(int i=0;i<arr.length;i++);{

                            System.out.println("请输入第"+(i+1)+"学生的成绩");

                            arr[i]=in.nextInt();

                      }

                    Arrays.sort(arr);

                               for(int i=0;i<arr.length;i++){

                                            System.out.println(arr[i]);

                                }

        }

}

用eclipse写代码吧，或者把你代码粘贴出来，发截图看着头疼