本帖最后由 奋发吧小白 于 2014-8-29 08:53 编辑
- <div class="blockcode"><blockquote>/*
- 有五个学生,每个学生有3门科=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成绩高低顺序放在磁盘文件“stu.txt”中。
- 分析:
- 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,并将改行数据取出封装成学生对象。
- 2,因为学生对象有很多,n那么就需要使用集合,因为学生总分需要排序,所以需要使用TreeSet
- 3,将集合中的信息写入到文件中
- */
- import java.io.*;
- import java.util.*;
- class Student implements Comparable<Student>
- {
- private String name;
- private int ma,cn,en;//代表三门成绩
- 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*78 ;
- }
- 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
- {
- BufferedReader bufr =
- new BufferedReader(new InputStreamReader(System.in));
- Set<Student>stus = new TreeSet<Student>();
- String line = null;
-
- 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("stu.txt"));
- for(Student stu:stus)
- {
- bufw.write(stu.toString());
- bufw.write(stu.getSum()+"");
- bufw.newLine();
- bufw.flush();
- }
- bufw.close();
- }
- }
- class StudentInfoTest
- {
- public static void main(String[] args) throws Exception
- {
- Set<Student> stus = StudentInfoTool.getStudents();
- StudentInfoTool.write2File(stus);
- }
- }
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