还是打印学生信息，遇到个问题 - 黑马程序员技术交流社区

package com.success;
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.util.Comparator;
import java.util.Date;
import java.util.TreeSet;
/*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。*/
public class Success12 {
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
TreeSet<Student> tm = new TreeSet<Student>(new Comp());
File f = new File("d:\\" + new Date().getTime() + ".txt");
String line = null;
String[] arr = null;
while ((line = br.readLine()) != null) {
if ("".equals(line))
break;
arr = line.split(",");
tm.add(new Student(arr[0], arr[1], arr[2], arr[3]));
}
br.close();
// 获取名字和成绩的最大长度
int nameMaxLen = 0, scoreMaxLen = 0;
for (Student s : tm) {
if (s.getName().length() > nameMaxLen)
nameMaxLen = s.getName().length();
if (s.getYw().length() > scoreMaxLen)
scoreMaxLen = s.getYw().length();
if (s.getSx().length() > scoreMaxLen)
scoreMaxLen = s.getSx().length();
if (s.getYy().length() > scoreMaxLen)
scoreMaxLen = s.getYy().length();
}
System.out.println("nameMaxLen:" + nameMaxLen);
System.out.println("scoreMaxLen:" + scoreMaxLen);
System.setOut(new PrintStream(f));// 设置默认输出设备为文件f
//按格式打印到文件f中
System.out.printf("%" + (nameMaxLen * 2 - 2) + "s%" + (scoreMaxLen + 1)
+ "s%" + (scoreMaxLen + 1) + "s%" + (scoreMaxLen + 1) + "s",
"名字", "语文", "数学", "英语");
System.out.println();
for (Student s : tm) {
System.out
.printf("%" + (nameMaxLen) + "s%" + (scoreMaxLen + 3)
+ "s%" + (scoreMaxLen + 3) + "s%"
+ (scoreMaxLen + 3) + "s", s.getName(), s.getYw(),
s.getSx(), s.getYy());
System.out.println();
}
}
}
class Student {
String name;
String yw;
String sx;
String yy;
Student(String name, String yw, String sx, String yy) {
this.name = name;
this.yw = yw;
this.sx = sx;
this.yy = yy;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getYw() {
return yw;
}
public void setYw(String yw) {
this.yw = yw;
}
public String getSx() {
return sx;
}
public void setSx(String sx) {
this.sx = sx;
}
public String getYy() {
return yy;
}
public void setYy(String yy) {
this.yy = yy;
}
}
class Comp implements Comparator<Student> {
@Override
public int compare(Student s1, Student s2) {
int sum1 = (int) (Double.parseDouble(s1.getYw())
+ Double.parseDouble(s1.getSx()) + Double.parseDouble(s1
.getYy()));
int sum2 = (int) (Double.parseDouble(s2.getYw())
+ Double.parseDouble(s2.getSx()) + Double.parseDouble(s2
.getYy()));
return new Integer(sum2).compareTo(new Integer(sum1));
}
}

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