/*有五个学生,每个学生有三门课的成绩,
* 从键盘输入以上数据(包括姓名,三门课成绩)
* 输入的格式:如:zhangsan,30,40,60计算出总成绩
* 并把学生的信息和计算出来的总分数高低顺序存放在磁盘文件"stud.txt"中。
*
*
* 1.描述学生对象。
* 2.定义一个可以操作学生对象的工具类。
*
* 思想:
* 1.通过获取键盘录入的一行数据,并将改行中的信息取出封装成学生对象。
* 2.因为学生对象有很多,那么就要存储,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 StudentIO implements Comparable<StudentIO>
{
private String name;
private int ma,cn,en;
private int sum;
StudentIO(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(StudentIO 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*78;
}
public boolean equals(Object obj)
{
if(!(obj instanceof StudentIO))
throw new ClassCastException("类型不匹配");
StudentIO s =(StudentIO)obj;
return this.name.equals(s.name)&& this.sum==s.sum;
}
public String toString()
{
return "studentIO["+name+", "+ma+", "+cn+", "+en+"]";
}
}
class StudentInfoTool
{
public static Set<StudentIO> getStudents()throws IOException
{
BufferedReader bufr =
new BufferedReader(new InputStreamReader(System.in));
String line = null;
Set<StudentIO> stus = new TreeSet<StudentIO>();
while((line=bufr.readLine())!=null)
{
if("over".equals(line))
break;
String[] info = line.split(",");
StudentIO stu = new StudentIO (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<StudentIO> stus)throws IOException
{
BufferedWriter bufw = new BufferedWriter(new FileWriter("stuinfo.txt"));
for(StudentIO stu : stus)
{
bufw.write(stu.toString()+"\t");
bufw.write(stu.getSum()+"");
bufw.newLine();
bufw.flush();
}
bufw.close();
}
}
public class StudentTest_IO
{
public static void main(String[] args) throws IOException
{
Set<StudentIO> stus = StudentInfoTool.getStudents();
StudentInfoTool.write2File(stus);
}
}
|
|