用Java写设计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。

好的，这是一个简单的Flight类的Java代码示例：

public class Flight {
    private String model; // 机型
    private String flightNumber; // 班次
    private int capacity; // 额定载客数
    private int passengers; // 实际载客数

    // 构造方法
    public Flight(String model, String flightNumber, int capacity, int passengers) {
        this.model = model;
        this.flightNumber = flightNumber;
        this.capacity = capacity;
        this.passengers = passengers;
    }

    // 输入属性
    public void setModel(String model) {
        this.model = model;
    }

    public void setFlightNumber(String flightNumber) {
        this.flightNumber = flightNumber;
    }

    public void setCapacity(int capacity) {
        this.capacity = capacity;
    }

    public void setPassengers(int passengers) {
        this.passengers = passengers;
    }

    // 输出属性
    public String getModel() {
        return model;
    }

    public String getFlightNumber() {
        return flightNumber;
    }

    public int getCapacity() {
        return capacity;
    }

    public int getPassengers() {
        return passengers;
    }

    // 求载客率
    public double loadFactor() {
        return (double) passengers / capacity;
    }

    // 重载toString方法
    @Override
    public String toString() {
        return "Flight{" +
                "model='" + model + '\'' +
                ", flightNumber='" + flightNumber + '\'' +
                ", capacity=" + capacity +
                ", passengers=" + passengers +
                '}';
    }
}

使用示例：

public class Main {
    public static void main(String[] args) {
        // 创建一个Flight对象
        Flight flight = new Flight("Boeing 737", "MU5635", 189, 157);

        // 输出对象属性
        System.out.println(flight.getModel());
        System.out.println(flight.getFlightNumber());
        System.out.println(flight.getCapacity());
        System.out.println(flight.getPassengers());

        // 求载客率
        System.out.println(flight.loadFactor());

        // 重载toString方法
        System.out.println(flight);
    }
}