java中的继承

Animal.java

public class Animal {
    /**
     * @auther JACK；
     * @method Con_structure、Getter and Setter、toString;
     * @package including:name、age、variety;
     * @inheritance Cats、Dogs and so on;
     * @limitAge age>0&&age<30;
     */
    private String name;
    private int age;
    private String variety;
/**仅对子类产生作用
    public Animal() {

    }
    public Animal(String name, int age, String variety) {
        this.name = name;
        this.age = age;
        this.variety = variety;
    }
 */
    @Override
    public String toString() {
        return "Animal{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", variety='" + variety + '\'' +
                '}';
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        if (age < 0 || age > 30) {
            System.out.println("请输入正确的年龄");
        } else {
            this.age = age;
        }
    }

    public String getName() {
        return name;
    }

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

    public String getVariety() {
        return variety;
    }

    public void setVariety(String variety) {
        this.variety = variety;
    }
    public void eat(){
        System.out.println(this.name +"正在吃饭");
    }
    public void sleep(){
        System.out.println(this.name+"正在吃饭");
    }
    public void crazy(){
        System.out.println(this.name + "正在发狂");
    }
    public void check(){
        System.out.println(this.name + "正在检查身体");
    }
}

plot.java

public class plot {
    /**
     * 使用单例设计模式设计小区名称；
     * 小区名称设置为“富贵小区”，且不可更改；
     */
    private static final plot NameInstance = new plot();
    private plot(){
    }
    public static plot getNameInstance(){
        return NameInstance;
    }
    public void PlotName(){
        System.out.println("富贵小区");
    }
}

Dogs.java

public class Dogs extends Animal {
}

Labrador.java

public class Labrador extends Dogs{
}

Cats,java

public class Cats extends Animal {

    }

Applicatin.java

public class ApplicationRun {
    public static void main(String[] args) {
        plot PLOT_NAME = plot.getNameInstance();
        PLOT_NAME.PlotName();
        Cats XIAO_ZHANG_PETS = new Cats();
        XIAO_ZHANG_PETS.setName("Tom");
        XIAO_ZHANG_PETS.setAge(2);
        XIAO_ZHANG_PETS.setVariety("布偶");
        System.out.println(XIAO_ZHANG_PETS);
        Dogs XIAO_MING_PETS = new Dogs();
        XIAO_MING_PETS.setName("Ton");
        XIAO_MING_PETS.setAge(4);
        XIAO_MING_PETS.setVariety("拉布拉多");
        System.out.println(XIAO_MING_PETS);
        XIAO_MING_PETS.eat();
        XIAO_ZHANG_PETS.check();
        Labrador labrador = new Labrador();


    }
}

注意：java支持多层继承，但是不支持一个class同时继承两个class,即class A extends B,C,这是错误的