/*
* 有五个学生,每个学生有3门课的成绩
* 从键盘输入以上数据(包括姓名、三门课成绩)
* 输入的格式: 如:张三,30,40,60 计算出总成绩
* 并把学生的信息和计算出的总分数从高到低放在磁盘文件“stud.txt”中。
*
* 1、描述学生对象。
* 2、定义一个可操作学生对象的工具类
*
* 思想
* 1、通过键盘录入一行数据,并将该行中的信息取出封装成学生对象
* 2、因为学生有很多,那么就需要存储,使用到集合。因为要对学生的总分排序
* 所以可以使用TreeSet。,
* 3、将集合的信息写入到一个文件中。
*
*/
import java.io.*;
import java.util.*;
class Student implements Comparable<Student>
{
private String name;
private int ma,cn,en;
private int sum;
Student(String name,int ma,int cn,int en)
{
this.name =name;
this.ma =ma;
this.cn =cn;
this.en =en;
sum =ma+cn+en;
}
public int compareTo(Student s)
{
int num =new Integer(this.sum).compareTo(new Integer(s.sum));
if(num==0)
return this.name.compareTo(s.name);
return num;
}
public String getName()
{
return name;
}
public int getSum()
{
return sum;
}
public int hashCode()
{
return name.hashCode()+sum*88;
}
public boolean equals(Object obj)
{
if(!(obj instanceof Student))
throw new ClassCastException("类型不匹配");
Student s =(Student) obj;
return this.name.equals(s.name)&&this.sum==s.sum;
}
public String toString()
{
return "Student["+name+":"+ma+":"+cn+":"+en+"]";
}
}
class StudentInfoTool
{
public static Set<Student> getStudents() throws Exception
{
return getStudents(null);
}
public static Set<Student> getStudents(Comparator<Student> cmp) throws Exception
{
BufferedReader bufr=
new BufferedReader(new InputStreamReader(System.in));
String line =null;
Set<Student> stus =null;
if(cmp==null)
stus =new TreeSet<Student>();
else
stus=new TreeSet<Student>(cmp);
while((line =bufr.readLine())!=null)
{
if("over".equals(line))
break;
String[] info =line.split(",");
Student stu = new Student(info[0],Integer.parseInt(info[1]),
Integer.parseInt(info[2]),Integer.parseInt(info[3]));
stus.add(stu);
}
bufr.close();
return stus;
}
public static void write2File(Set<Student> stus)throws Exception
{
BufferedWriter bufw=new BufferedWriter(new FileWriter("stuinfo.txt"));
for(Student stu:stus)
{
bufw.write(stu.toString()+"\t"+stu.getSum()+"");
bufw.newLine();
bufw.flush();
}
bufw.close();
}
}
public class StudentInfoTest
{
public static void main(String[] args)throws Exception
{
Comparator<Student> cmp =Collections.reverseOrder();
Set<Student> stus =StudentInfoTool.getStudents(cmp);
StudentInfoTool.write2File(stus);
}
}
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