- import java.io.*;
- import java.util.*;
- public class test
- {
- /**
- * 有五个学生,每个学生有3门课(语文、数学、英语)的成绩,写一个程序接收从键盘输入学生的信息,
- * 输入格式为:name,30,30,30(姓名,三门课成绩),然后把输入的学生信息按总分从高到低的顺序写入到一个名称"stu.txt"文件中。
- * 要求:stu.txt文件的格式要比较直观,打开这个文件,就可以很清楚的看到学生的信息。
- *
- * @throws IOException
- */
- public static void main(String[] args) throws Exception
- {
- BufferedReader bd = new BufferedReader(new InputStreamReader(System.in));
- BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\stus.txt"));
- //System.out.println("请输入学生成绩格式是:姓名,语文成绩,数学成绩,英语成绩");
- // 创建TreeSet集合对象,在TreeSet的构造函数中传入比较器,按照总分比较
- TreeSet<Student> ts = new TreeSet<Student>();
- // 录入五个学生,所以以集合中的学生个数为判断条件,如果size是小于5就进行存储
- while (ts.size() < 5)
- {
- // 将录入的字符串切割,用逗号切割,会返回一个字符串数组,
- //将字符串数组中从二个元素转换成int数,第一个是姓名
- String line = bd.readLine();
- String[] arr = line.split(",");
- int chinese = Integer.parseInt(arr[1]);
- int math = Integer.parseInt(arr[2]);
- int english = Integer.parseInt(arr[3]);
- // 将转换后的结果封装成Student对象,将Student添加到TreeSet集合中
- ts.add(new Student(arr[0], chinese, math, english));
- }
- // 遍历TreeSet集合打印每一个Student对象
- for (Student s : ts)
- {
- //System.out.println(s);
- bw.write(s.toString());
- bw.newLine();
- }
- bd.close();
- bw.close();
- }
- }
- class Student implements Comparable
- {
- private String name;
- private int chinese;
- private int math;
- private int english;
- private int sum;
- public Student(String name, int chinese, int math, int english)
- {
- this.name = name;
- this.chinese = chinese;
- this.math = math;
- this.english = english;
- sum = chinese + math + english;
- }
- public int getSum()
- {
- return sum;
- }
- public String toString()
- {
- return "["+name + "," + chinese + "," + math + "," + english + "," + sum+"]";
- }
-
- public int compareTo(Object obj)
- {
-
- if(!(obj instanceof Student))
- throw new RuntimeException("不是学生对象");
- Student s = (Student)obj;
- if(this.sum<s.sum)
- return 1;
- if(this.sum==s.sum)
- {
- return s.name.compareTo(this.name);
- }
- return -1;
- }
- }
复制代码
结果:
[j,99,99,99,297]
[i,100,90,90,280]
[n,90,96,85,271]
[y,89,79,98,266]
[h,88,88,88,264]
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