Java 类继承实例：交通工具、汽车、火车、飞机

以下是使用 Java 定义交通工具、汽车、火车、飞机这些类的示例代码：

// 定义交通工具类
public class Transport {
    private String name;
    private int speed;

    // 初始化块，设置通用代码
    {
        System.out.println('Transport is created.');
    }

    // 构造方法1
    public Transport(String name, int speed) {
        this.name = name;
        this.speed = speed;
    }

    // 构造方法2
    public Transport(String name) {
        this(name, 0);
    }

    // 构造方法3
    public Transport() {
        this('Unknown', 0);
    }

    public void move() {
        System.out.println(name + ' is moving at speed ' + speed + ' km/h.');
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getSpeed() {
        return speed;
    }

    public void setSpeed(int speed) {
        this.speed = speed;
    }
}

// 定义汽车类，继承自交通工具类
public class Car extends Transport {
    private int seats;

    // 初始化块，设置通用代码
    {
        System.out.println('Car is created.');
    }

    // 构造方法1
    public Car(String name, int speed, int seats) {
        super(name, speed);
        this.seats = seats;
    }

    // 构造方法2
    public Car(String name, int seats) {
        this(name, 0, seats);
    }

    // 构造方法3
    public Car(String name) {
        this(name, 0, 0);
    }

    public int getSeats() {
        return seats;
    }

    public void setSeats(int seats) {
        this.seats = seats;
    }
}

// 定义火车类，继承自交通工具类
public class Train extends Transport {
    private int carriages;

    // 初始化块，设置通用代码
    {
        System.out.println('Train is created.');
    }

    // 构造方法1
    public Train(String name, int speed, int carriages) {
        super(name, speed);
        this.carriages = carriages;
    }

    // 构造方法2
    public Train(String name, int carriages) {
        this(name, 0, carriages);
    }

    // 构造方法3
    public Train(String name) {
        this(name, 0, 0);
    }

    public int getCarriages() {
        return carriages;
    }

    public void setCarriages(int carriages) {
        this.carriages = carriages;
    }
}

// 定义飞机类，继承自交通工具类
public class Airplane extends Transport {
    private int passengers;

    // 初始化块，设置通用代码
    {
        System.out.println('Airplane is created.');
    }

    // 构造方法1
    public Airplane(String name, int speed, int passengers) {
        super(name, speed);
        this.passengers = passengers;
    }

    // 构造方法2
    public Airplane(String name, int passengers) {
        this(name, 0, passengers);
    }

    // 构造方法3
    public Airplane(String name) {
        this(name, 0, 0);
    }

    public int getPassengers() {
        return passengers;
    }

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

在上面的代码中，交通工具类是基类，汽车、火车、飞机类都继承自它。每个类中都提供了三个构造方法，分别用于不同的参数组合，而这些构造方法中的通用代码则通过初始化块来实现。每个类还提供了相应的属性和方法，用于描述具体的交通工具及其行驶特点。