设计Flight类。要求：（1）具有机型、班次、额定载客数和实际载客数等属性；（2）具有输入/输出属性功能；（3）求载客率；（4）重载toString方法，用于对象属性值的输出

下面是一个符合要求的Flight类的示例：

public class Flight {
    private String aircraftType;
    private String flightNumber;
    private int capacity;
    private int actualPassengers;

    public Flight(String aircraftType, String flightNumber, int capacity, int actualPassengers) {
        this.aircraftType = aircraftType;
        this.flightNumber = flightNumber;
        this.capacity = capacity;
        this.actualPassengers = actualPassengers;
    }

    public void input() {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入机型：");
        this.aircraftType = scanner.nextLine();
        System.out.print("请输入班次：");
        this.flightNumber = scanner.nextLine();
        System.out.print("请输入额定载客数：");
        this.capacity = scanner.nextInt();
        System.out.print("请输入实际载客数：");
        this.actualPassengers = scanner.nextInt();
    }

    public void output() {
        System.out.println("机型：" + this.aircraftType);
        System.out.println("班次：" + this.flightNumber);
        System.out.println("额定载客数：" + this.capacity);
        System.out.println("实际载客数：" + this.actualPassengers);
        System.out.println("载客率：" + this.getLoadFactor());
    }

    public double getLoadFactor() {
        return (double) this.actualPassengers / this.capacity;
    }

    @Override
    public String toString() {
        return "Flight{" +
                "aircraftType='" + aircraftType + '\'' +
                ", flightNumber='" + flightNumber + '\'' +
                ", capacity=" + capacity +
                ", actualPassengers=" + actualPassengers +
                '}';
    }
}

在这个示例中，Flight类包含了机型、班次、额定载客数和实际载客数等属性，并提供了输入/输出属性的功能。其中，input方法用于从控制台读取用户输入，output方法用于将对象的属性值输出到控制台。此外，Flight类还提供了getLoadFactor方法，用于计算载客率。最后，重载了toString方法，用于将对象的属性值以字符串的形式输出。