java根据学生总分按顺序排名，怎么调用排序？无法应用。求大神修改！

Question

public class Student{
String name,number;
double s1,s2,s3,sum;
public Student(String n,String no,double x1,double x2,double x3)
{ name=n;
number=no;
s1=x1;
s2=x2;
s3=x3;
sum=s1+s2+s3;
}
public static void paixu(Student v[])
{ for(int i=0;i<a.length-1;i++)
{Student t=new Student();
for(int j=i+1;j<a.length;j++)
if(v[i].sum<v[j].sum)
{t=v[i];
v[i]=v[j];
v[j]=t;
}
}
}
void print()
{System.out.println(name+" "+number+" "+s1+" "+s2+" "+s3);
}
public static void main(String args[])
{
Student s[]=new Student[5];
s[0]=new Student("Zhangsan","20140001",89,87,90);
s[1]=new Student("Lisi","20140002",88,87,90);
s[2]=new Student("Wangwu","20140003",89,80,90);
s[3]=new Student("Zhaohong","20140004",89,87,78);
s[4]=new Student("Gaozi","20140005",81,87,90);

s[0].paixu();

}

}

Answer 1

import java.util.Arrays;

public class Student {

String name,number;
double s1,s2,s3,sum;
//student方法，返回值为一个学生3门课程分数之和
public double Student(String n,String no,double x1,double x2,double x3){
name=n;
number=no;
s1=x1;
s2=x2;
s3=x3;
return s1+s2+s3;
}
//main方法
public static void main(String args[]){
Student stu=new Student();//实例化对象
double[] s=new double[5];
//调用stu方法，将分数和给一个double数组
s[0]=stu.Student("Zhangsan","20140001",89,87,90);
s[1]=stu.Student("Lisi","20140002",88,87,90);
s[2]=stu.Student("Wangwu","20140003",89,80,90);
s[3]=stu.Student("Zhaohong","20140004",89,87,78);
s[4]=stu.Student("Gaozi","20140005",81,87,90);
Arrays.sort(s);//排序方法，从小到大
for(int i=0;i<5;i++){
System.out.println(s[i]);
}
}

}

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有注释，应该能看懂

追问

可是如果想用原先的排序法 该怎么调用