有关集合和IO的代码大家帮忙看看 - 黑马程序员技术交流社区

import java.util.*;
import java.io.*;
//为了使其属性具备比较性要实现Comparable接口
class Student implements Comparable
{
private String name;
private int ma,cn,en;//ma:数学，cn：语文 en:英语
private int sum;//sum:总成绩
public 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;
}
//覆盖compareTo方法：
public int compareTo(Object obj){
Student s=(Student)obj;//强转
int num=new Integer(this.sum).compareTo(new Integer(s.sum));//比较总分数
if(num==0){
//如果总分数相等就比较姓名
return this.name.compareTo(s.name);
}
return num;
}
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 "String["+name+","+ma+","+cn+","+en+"]";
}
public String getName(){
return name;
}
public int getMa(){
return ma;
}
public int getCn(){
return cn;
}
public int getEn(){
return en;
}
public int getSum(){
return sum;
}
}
//定义工具类
class StudentInfoTool
{
public static Set<Student>getStudents()throws IOException{
//键盘录入
BufferedReader bufr=new BufferedReader(new InputStreamReader(System.in));
String line=null;
//创建集合对象
Set<Student> stus=new TreeSet<Student>();
while((line=bufr.readLine())!=null){
if("over".equals(line)){
break;
}
String []info=line.split(",");//以“，”来切割键盘输入的数据
Student stu=new Student(info[0],Integer.parseInt(info[1]),Integer.parseInt(info[2]),Integer.parseInt(info[3]));
stus.add(stu);//将对象存到集合
}
bufr.close();
return stus;//返回集合
}
//将集合中的数据写到文件中
public static void write2File(Set<Student> stus)throws IOException{
BufferedWriter bfs=new BufferedWriter(new FileWriter("d:\\123.txt"));
for(Student s:stus){
bfs.write(s.getName());
bfs.write(+s.getMa()+"");
bfs.write(s.getCn()+"");
bfs.write(s.getEn()+"");
bfs.write(s.getSum()+"");
bfs.newLine();
bfs.flush();
}
bfs.close();
}
}
class StudentInfoTest
{
public static void main(String[] args) throws IOException
{
Set<Student> stu=StudentInfoTool.getStudents();
StudentInfoTool.write2File(stu);
}
}

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