周末送分活动！答题拿技术分~ - 黑马程序员技术交流社区

import java.io.*;
import java.util.*;
public class Test {
public static void main(String[] args)throws Exception{
//传入学生人数
Student(5);
}
//键盘录入学生
public static void Student(int number)throws Exception{
//创建Scanner对象接受从控制台输入
Scanner in=new Scanner(System.in);
//因为可能会出现姓名和总分都一样的学生，为了保证学生不丢失，建立List容器
List list=new ArrayList();
//循环录入学生到集合,排好顺序
System.out.println("输入格式为：姓名,语文,数学,英语");
for(int x=1;x<=number;x++){
System.out.println("请输入第"+x+"个学生的信息");
String[] s=in.nextLine().split(",");
int a=Integer.parseInt(s[1]);
int b=Integer.parseInt(s[2]);
int c=Integer.parseInt(s[3]);
Student stu=new Student(s[0],a,b,c);
list.add(stu);
}
//用比较器进行总分从高到低的排序
Collections.sort(list,new StuCompare());
//定义输出流输出到stu.txt
BufferedWriter bufw=new BufferedWriter(new FileWriter("stu.txt"));
for(Student stu:list){
bufw.write(stu.getStu());
bufw.newLine();
bufw.flush();
}
//关闭资源
in.close();
bufw.close();
}
}
//学生类型
class Student{
private String name;
private int a, b, c,sum;
//学生对象建立需要传入姓名和3门课的成绩
Student(String name, int a, int b, int c){
this.name=name;
this.a=a;
this.b=b;
this.c=c;
sum=a+b+c;
}
public int getsum(){
return sum;
}
//输出一个符合格式的字符串
public String getStu(){
return name+" 数学："+a+" 语文："+b+" 英语："+c+" 总分："+sum;
}
}
//定义比较器，按总分排序
class StuCompare implements Comparator{
public int compare(Student s1,Student s2){
int a=new Integer(s2.getsum()).compareTo(s1.getsum());
return a;
}

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import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.TreeSet;
public class StirngDemo {
public static void main(String[] args) {
// 想读多少都可以，键盘输入格式名字,成绩,成绩,成绩(注意逗号小写)
try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
BufferedWriter bw = new BufferedWriter(new FileWriter("e:\\stu.txt"))) {
String str = null;
// 建立规则从高分到低分
TreeSet<Student> ts = new TreeSet<>((o1, o2) -> o2.sub() - o1.sub());
while ((str = br.readLine()) != null) {
if (str.equals("over"))
break;
String[] s = str.split(",");
// 学生对象已new好存入集合中进行排序
Student xue = new Student(s[0], Integer.parseInt(s[1]), Integer.parseInt(s[2]), Integer.parseInt(s[3]));
ts.add(xue);
}
bw.write("姓名\t数学\t语文\t英语");
bw.flush();
bw.newLine();
// 执行打印
for (Student student : ts) {
bw.write(student.getName()+"\t"+student.getShu()+"\t"+student.getYu()+"\t"+student.getYing());
bw.newLine();
bw.flush();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
//学生对象，把名字各科成绩总分变成属性，给予总分方法
class Student {
private String name;
private int shu, yu, ying;
public String getName() {
return name;
}
public Student(String name, int shu, int yu, int ying) {
this.name = name;
this.shu = shu;
this.yu = yu;
this.ying = ying;
}
public int getShu() {
return shu;
}
public int getYu() {
return yu;
}
public int getYing() {
return ying;
}
public int sub() {
return shu + ying + yu;
}
}

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