运用Java在eclipse上实现住宿学生信息包括：学号、姓名、性别、年龄、班级、用电量、用水量 等信息。教工信息包括职工号、姓名、性别、年龄、工作部门、用电量、用水量等信息。 能计算出学生和教工每月所要交的电费和水费。定义一个人员类，实现学生和教工共同的信 息和行为。同时实现保存和读取的工能

以下是一个可能的解决方案：

首先，我们需要定义一个 Person 类，用于保存学生和教工共同的信息：

public class Person {
    private String id;  // 学号或职工号
    private String name;
    private String gender;
    private int age;
    private double electricity;
    private double water;

    public Person(String id, String name, String gender, int age, double electricity, double water) {
        this.id = id;
        this.name = name;
        this.gender = gender;
        this.age = age;
        this.electricity = electricity;
        this.water = water;
    }

    // getters and setters
}

然后，我们可以定义一个 Student 类和一个 Teacher 类，分别继承自 Person 类，并且添加学生和教工特有的信息和行为：

public class Student extends Person {
    private String clazz;  // 班级

    public Student(String id, String name, String gender, int age, String clazz, double electricity, double water) {
        super(id, name, gender, age, electricity, water);
        this.clazz = clazz;
    }

    // 计算电费和水费
    public double getElectricityFee() {
        return electricity * 0.5;  // 假设电费单价为0.5元/kWh
    }

    public double getWaterFee() {
        return water * 2;  // 假设水费单价为2元/m³
    }

    // getters and setters
}

public class Teacher extends Person {
    private String department;  // 工作部门

    public Teacher(String id, String name, String gender, int age, String department, double electricity, double water) {
        super(id, name, gender, age, electricity, water);
        this.department = department;
    }

    // 计算电费和水费
    public double getElectricityFee() {
        return electricity * 0.8;  // 假设电费单价为0.8元/kWh
    }

    public double getWaterFee() {
        return water * 3;  // 假设水费单价为3元/m³
    }

    // getters and setters
}

最后，我们可以在主函数中创建学生和教工对象，并计算他们的电费和水费：

public static void main(String[] args) {
    Student s = new Student("001", "张三", "男", 18, "计算机科学与技术1班", 100, 10);
    Teacher t = new Teacher("1001", "李四", "女", 30, "计算机系", 200, 20);

    System.out.println(s.getName() + "的电费为：" + s.getElectricityFee() + "元");
    System.out.println(s.getName() + "的水费为：" + s.getWaterFee() + "元");
    System.out.println(t.getName() + "的电费为：" + t.getElectricityFee() + "元");
    System.out.println(t.getName() + "的水费为：" + t.getWaterFee() + "元");
}

当然，我们还需要实现保存和读取功能。可以使用 Java 的序列化机制来实现：

public class DataIO {
    public static void savePersonList(List<Person> list, String fileName) throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(fileName));
        oos.writeObject(list);
        oos.close();
    }

    public static List<Person> loadPersonList(String fileName) throws IOException, ClassNotFoundException {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(fileName));
        List<Person> list = (List<Person>) ois.readObject();
        ois.close();
        return list;
    }
}

这样，我们就可以把学生和教工对象保存到文件中，并在需要时读取出来。