Java快速教程--vamei 学习笔记（基础篇）

 链接：http://www.cnblogs.com/vamei/archive/2013/03/31/2991531.html

java快速教程第1课 从HelloWorld到面向对象

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/14/2958654.html

java快速教程第2课 方法与数据成员

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/25/2964430.html

java快速教程第3课 构造器与方法重载

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/26/2981728.html

java快速教程第4课 封装与接口

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/27/2982209.html

public class Test
{
    public static void main(String[] args)
    {
        Human aPerson = new Human(160);
        System.out.println(aPerson.getHeight());
        aPerson.growHeight(170);
        System.out.println(aPerson.getHeight());
        aPerson.repeatBreath(100);
    }

}

class Human
{
    /**
     * constructor
     */
    public Human(int h)
    {
        this.height = h;
        System.out.println("I'm born");
    }

    /**
     * accessor
     */
    public int getHeight()
    {
       return this.height;
    }

    /**
     * mutator
     */
    public void growHeight(int h)
    {
        this.height = this.height + h;
    }

     /**
      * encapsulated, for internal use
      */
    private void breath()
    {
        System.out.println("hu...hu...");
    }


   /**
    * call breath()
    */
    public void repeatBreath(int rep)
    {
        int i;
        for(i = 0; i < rep; i++) {
            this.breath();
        }
    }

    private int height; // encapsulated, for internal use
}

java快速教程第5课 实施接口

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/29/2982206.html

package text;

interface Cup
{
    void addWater(int w);
    void drinkWater(int w);
}

class Text implements Cup
{
    public void addWater(int w)
    {
        this.water = this.water + w;
        System.out.println(water);
    }
    
    public void drinkWater(int w)
    {
        this.water = this.water - w;
        System.out.println(water);
    }
    
    public int waterContent( )
    {
        return this.water;
    }
    
    public void play( )
    {
        System.out.println("la...la...");
    }
    
    private int water = 0;
    
    public static void main(String args[ ])
    {
        Text obj = new Text( );
        obj.addWater(10);
        obj.drinkWater(4);
    }
}

java快速教程第6课组合

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/29/2982206.html

package text;

public class Text
{
    public static void main(String[] args)
    {
        Torch aTorch = new Torch( );
        System.out.println("Charge: 2 hours");
        aTorch.charge(2);
        System.out.println("First Turn On: 3 hours");
        aTorch.turnOn(3);
        System.out.println("Second Turn On:  3 hours");
        aTorch.turnOn(3);
    }
}

class Battery 
{
    public void chargeBattery(double p)
    {
        if (this.power < 1.)
        {
            this.power = this.power + p;
        }
    }
    
    public boolean useBattery(double p)
    {
        if (this.power >= p)
        {
            this.power = this.power - p;
            return true;
        }
        else
        {
            this.power = 0.0;
            return false;
        }
    }
    
    private double power = 0.0;
}

class Torch
{
    /**
     *  10% power per hour use
     *   warning when out of power
     */
    public void turnOn(int hours)
    {
        boolean usable;
        usable = this.theBattery.useBattery(hours*0.1);
        if ( usable != true )
        {
            System.out.println("No more usable, must charge");
        }
    }
    
    /**
     *  20% power per hour charge
     */
    public void charge(int hours)
    {
        this.theBattery.chargeBattery(hours*0.2);        
    }
    
    /**
     *  composition
     */
    private Battery theBattery = new Battery();
}

java快速教程第7课 包的建立和使用

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/29/2982206.html

java快速教程第8课 继承

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/29/2982232.html

package test;

public class Test 
{
    public static void main(String[ ] args)
    {
        System.out.println("hello world");
        Woman aWoman = new Woman();
        aWoman.growHeight(120);
        System.out.println(aWoman.getHeight());
        aWoman.breath();
        aWoman.giveBirth();
    }
}

class Human
{
    /**
     * contructor
     */
    public Human(int height)
    {
        this.height = height;
    }
    
    public Human()
    {
    }
    
     /**
      * accessor
      */
    public int getHeight()
    {
        return this.height;
    }

    /**
     *    * mutator
     */
    public void growHeight(int h)
    {
        this.height = this.height + h;
        }

    /**
    * breath
    */
    public void breath()
    {
        System.out.println("hu...hu...");
    }

    private int height; 
}

class Woman extends Human
{    
    /**
     * constructor
     */
    public Woman(int h)
    {
        super(h); //base class construtor
        System.out.println("Hello, Pandora!");
    }
    
    public Woman()
    {
    }
    
    /**
     *  new method
     */
    public Human giveBirth()
    {    
        System.out.println("Give birth");
        return (new Human(20));
    }
    
    /**
     * override Human.breath( )
     */
    public  void breath()
    {
        super.breath( );
        System.out.println("su...");
    }
}

 java快速教程第9课  类数据与类方法

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/31/2988622.html

package test;

public class Test 
{
    public static void main(String[ ] args)
    {
        System.out.println(Human.getPopulation());
        Human aPerson = new Human(160);
        System.out.println(aPerson.getPopulation());
    }
}

class Human
{   
    /**
     * constructor
     */
    public Human(int h)
    {
        this.height = h;
        Human.population = Human.population +1;
    }

    /**
     * accessor
     */
    public int getHeight()
    {
       return this.height;
    }

    /**
     * mutator
     */
    public void growHeight(int h)
    {
        this.height = this.height + h;
    }

    /**
     * breath
     */
    public void breath()
    {
        System.out.println("hu...hu...");
    }

    private int height; 

    /*
     * static method, access population
     */
    public static int getPopulation()
    {
        return Human.population;
    }

    private static int population;
    private static boolean is_mammal = true;

}

java快速教程第10课 接口的继承与抽象类

学习网址：http://www.cnblogs.com/vamei/archive/2013/03/31/2982240.html

java快速教程第11课 对象引用

学习网址：http://www.cnblogs.com/vamei/archive/2013/04/01/2992484.html

package test;

public class Test
{
    public static void main(String[] args)
        {
             Human aPerson = new Human(160);
             Human dummyPerson = aPerson;
             System.out.println(dummyPerson.getHeight());
             aPerson.growHeight(20);
             System.out.println(dummyPerson.getHeight());
        }
}

class Human
{   
    /**
     * constructor
     */
    public Human(int h)
    {
        this.height = h;
    }

    /**
     * accessor
     */
    public int getHeight()
    {
       return this.height;
    }

    /**
     * mutator
     */
    public void growHeight(int h)
    {
        this.height = this.height + h;
    }

    private int height;
}

java快速教程第12课 多态

学习网址：http://www.cnblogs.com/vamei/archive/2013/04/01/2992662.html

将一个衍生类引用转换为其基类引用，这叫做向上转换(upcast)或者宽松转换。