创建一个学生类（包括姓名，年龄，班级，密码），创建若干该类的对象并保存到文件中（密码不保存:)，从文件读取对象后显示在屏幕上，Java编程）

好的，这是一个简单的实现：

import java.io.*;

class Student implements Serializable {
    private String name;
    private int age;
    private String className;
    private transient String password;

    public Student(String name, int age, String className, String password) {
        this.name = name;
        this.age = age;
        this.className = className;
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getClassName() {
        return className;
    }

    public String getPassword() {
        return password;
    }

    public String toString() {
        return "Name: " + name + "\nAge: " + age + "\nClass: " + className;
    }
}

public class Main {
    public static void main(String[] args) {
        Student s1 = new Student("John", 18, "Class A", "password123");
        Student s2 = new Student("Mary", 19, "Class B", "password456");

        try {
            // Save objects to file
            FileOutputStream fileOut = new FileOutputStream("students.ser");
            ObjectOutputStream out = new ObjectOutputStream(fileOut);
            out.writeObject(s1);
            out.writeObject(s2);
            out.close();
            fileOut.close();
            System.out.println("Students saved to file.");

            // Read objects from file
            FileInputStream fileIn = new FileInputStream("students.ser");
            ObjectInputStream in = new ObjectInputStream(fileIn);
            Student s3 = (Student) in.readObject();
            Student s4 = (Student) in.readObject();
            in.close();
            fileIn.close();

            // Print objects to screen
            System.out.println("Student 1:");
            System.out.println(s3);
            System.out.println("\nStudent 2:");
            System.out.println(s4);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

这个程序创建了一个`Student`类，其中包括姓名、年龄、班级和密码等信息。然后，它创建了两个`Student`对象`s1`和`s2`，并将它们保存到名为`students.ser`的文件中。它然后再从文件中读取这些对象，并将它们打印到屏幕上。

注意，`password`属性被标记为`transient`，这意味着它不会被序列化到文件中。这是为了保护学生的隐私，以避免密码泄露。