java基础之封装继承

java封装将代码及其处理数据绑定在一起的编程机制，保证程序和数据不受外界干扰和误用，想成一个黑匣子，给一个输出出现结果，不用考虑内部的实现。

java继承一个对象获取令一个对象的属性，使其成为更通用的实例的类。

1.写一个父类，里面拥有一些属性。

public class Animal {
	private Double weight;
	private String color;
	private String type;
	/**
	 * @return the weight
	 */
	public Double getWeight() {
		return weight;
	}
	/**
	 * @param weight the weight to set
	 */
	public void setWeight(Double weight) {
		this.weight = weight;
	}
	/**
	 * @return the color
	 */
	public String getColor() {
		return color;
	}
	/**
	 * @param color the color to set
	 */
	public void setColor(String color) {
		this.color = color;
	}
	/**
	 * @return the type
	 */
	public String getType() {
		return type;
	}
	/**
	 * @param type the type to set
	 */
	public void setType(String type) {
		this.type = type;
	}
	public Animal(Double weight, String color, String type) {
		this.weight = weight;
		this.color = color;
		this.type = type;
	}
	
}

　　2.子类继承父类，并添加一些自己的属性。

public class Dog extends Animal {
    
    private String name;
    

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    public void action(int i){
        if (i==1) {
            System.out.println("跑步");
        }else {
            System.out.println("溜达");
        }
        
    }
    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }


    public Dog(Double weight, String color, String type,String name) {
        super(weight, color, type);
        this.name=name;
        
    }
    public static void main(String[] args) {
        Dog a=new Dog(11d, "color", "狗", "阿拉斯加");
        System.out.println(a.name);
        a.getType();
        a.action(1);
        a.action(344);
    }

}

 二.多态