java用到try...catch方法 定义一个学生类Student,包含属性name, age, id,性别，创高跑步公里数distance。设置每个属性的getter/setter方法 定义一个班级类，包含属性班级名称，学院等属性,班级的所有学生都存储在里面(49人)。 -把班级班级成员写入要- -个tbxt文件中， 每个学生占一行,每个属性逗号分割 例如: 姓名:张三，学号:111... 姓名:李四,学号:112... -从txt文件重新读取然后把班级成员写入要- 个csv文件中(Excel)

好的，我会尽力回答。首先，这是一个Java编程的问题，需要用到文件读写、类的定义、属性和方法的设置等知识点。下面是我给出的代码实现，其中包含了注释解析。

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

// 学生类
class Student {
    private String name;
    private int age;
    private String id;
    private String gender;
    private double distance;

    public Student() {}

    public Student(String name, int age, String id, String gender, double distance) {
        this.name = name;
        this.age = age;
        this.id = id;
        this.gender = gender;
        this.distance = distance;
    }

    // getter和setter方法
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public double getDistance() {
        return distance;
    }

    public void setDistance(double distance) {
        this.distance = distance;
    }

    // toString方法，用于输出学生信息
    public String toString() {
        return "姓名:" + name + ", 年龄:" + age + ", 学号:" + id + ", 性别:" + gender + ", 跑步公里数:" + distance;
    }
}

// 班级类
class Class {
    private String name;
    private String college;
    private List<Student> students;

    public Class() {}

    public Class(String name, String college) {
        this.name = name;
        this.college = college;
        this.students = new ArrayList<Student>();
    }

    // 添加学生
    public void addStudent(Student student) {
        students.add(student);
    }

    // 将班级成员写入txt文件中
    public void writeToFile(String filename) {
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter(filename));
            for (Student student : students) {
                writer.write(student.getName() + "," + student.getAge() + "," + student.getId() + "," + student.getGender() + "," + student.getDistance() + "\n");
            }
            writer.close();
        } catch (IOException e) {
            System.out.println("写入文件失败：" + e.getMessage());
        }
    }

    // 从txt文件中读取班级成员
    public void readFromFile(String filename) {
        try {
            BufferedReader reader = new BufferedReader(new FileReader(filename));
            String line;
            while ((line = reader.readLine()) != null) {
                String[] fields = line.split(",");
                String name = fields[0];
                int age = Integer.parseInt(fields[1]);
                String id = fields[2];
                String gender = fields[3];
                double distance = Double.parseDouble(fields[4]);
                Student student = new Student(name, age, id, gender, distance);
                students.add(student);
            }
            reader.close();
        } catch (IOException e) {
            System.out.println("读取文件失败：" + e.getMessage());
        }
    }

    // 将班级成员写入csv文件中
    public void writeToCsv(String filename) {
        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter(filename));
            writer.write("姓名,年龄,学号,性别,跑步公里数\n");
            for (Student student : students) {
                writer.write(student.getName() + "," + student.getAge() + "," + student.getId() + "," + student.getGender() + "," + student.getDistance() + "\n");
            }
            writer.close();
        } catch (IOException e) {
            System.out.println("写入文件失败：" + e.getMessage());
        }
    }
}

public class Test {
    public static void main(String[] args) {
        // 创建班级对象
        Class clazz = new Class("一班", "计算机科学与技术学院");
        // 添加学生
        clazz.addStudent(new Student("张三", 20, "20190101", "男", 10.5));
        clazz.addStudent(new Student("李四", 19, "20190102", "女", 8.3));
        // 将班级成员写入txt文件中
        clazz.writeToFile("class.txt");
        // 从txt文件中读取班级成员
        clazz.readFromFile("class.txt");
        // 将班级成员写入csv文件中
        clazz.writeToCsv("class.csv");
    }
}

在代码中，我们首先定义了一个`Student`类，包含了姓名、年龄、学号、性别、跑步公里数等属性，以及对应的getter和setter方法。然后定义了一个`Class`类，包含了班级名称、学院等属性和学生列表，以及添加学生、将班级成员写入txt文件、从txt文件中读取班级成员、将班级成员写入csv文件等方法。最后，在`main`函数中创建了一个班级对象，并添加了两个学生，然后将班级成员写入txt文件、从txt文件中读取班级成员、将班级成员写入csv文件。

注意，为了方便起见，这里只添加了两个学生，实际情况中需要添加所有学生。另外，文件的写入和读取操作需要用到异常处理（try...catch语句），以防止程序出错导致程序崩溃。