自定义异常：超载异常

输入格式：第一行输入一个大于零的整数或小数，当做货船的最大装载量maxWeight。
第二行输入两个大于零的整数或小数，当做尝试装载上货船的两个集装箱的重量，中间以空格隔开。

package csdn003;

import java.util.Scanner;

/**
 * @author wf
 */
public class OverLoadException extends Exception{
    private String message;

    @Override
    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public OverLoadException(double n) {
        this.message = "无法再装载重量是" + n + "吨的集装箱";
    }

    public void showMessage() {
        System.out.println(this.message);
    }
}

class CargoShip {
    private double actualWeight = 0;
    private double maxWeight;

    public double getActualWeight() {
        return actualWeight;
    }

    public void setActualWeight(double actualWeight) {
        this.actualWeight = actualWeight;
    }

    public double getMaxWeight() {
        return maxWeight;
    }

    public void setMaxWeight(double maxWeight) {
        this.maxWeight = maxWeight;
    }

    public void loading(double weight) throws OverLoadException {
        this.actualWeight += weight;
        if (actualWeight > maxWeight) {
            throw new OverLoadException(weight);
        }
        System.out.println("目前共装载了" + actualWeight + "吨货物");
    }


}

class Main {
    public static void main(String[] args) {
        CargoShip myship = new CargoShip();
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入最大载重量：");
        double maxWeight = scanner.nextDouble();
        myship.setMaxWeight(maxWeight);
        try {
            System.out.println("请输入集装箱1的重量：");
            double weight1 = scanner.nextDouble();
            myship.loading(weight1);
            System.out.println("请输入集装箱2的重量：");
            double weight2 = scanner.nextDouble();
            myship.loading(weight2);
        }catch (OverLoadException e) {
            e.showMessage();
        }finally {
            System.out.println("货船将正点起航");
        }

    }
}