吴裕雄--天生自然轻量级JAVA EE企业应用开发Struts2Sping4Hibernate整合开发学习笔记：企业应用开发的思考和策略_SimpleFactory

/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
public class BetterPrinter implements Output
{
    private String[] printData = new String[MAX_CACHE_LINE * 2];
    // 用以记录当前需打印的作业数
    private int dataNum = 0;
    public void out()
    {
        // 只要还有作业，继续打印
        while(dataNum > 0)
        {
            System.out.println("高速打印机正在打印：" + printData[0]);
            // 把作业队列整体前移一位，并将剩下的作业数减1
            System.arraycopy(printData , 1, printData, 0, --dataNum);
        }
    }
    public void getData(String msg)
    {
        if (dataNum >= MAX_CACHE_LINE * 2)
        {
            System.out.println("输出队列已满，添加失败");
        }
        else
        {
            // 把打印数据添加到队列里，已保存数据的数量加1。
            printData[dataNum++] = msg;
        }
    }
}

/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
public class Computer
{
    private Output out;

    public Computer(Output out)
    {
        this.out = out;
    }
    // 定义一个模拟获取字符串输入的方法
    public void keyIn(String msg)
    {
        out.getData(msg);
    }
    // 定义一个模拟打印的方法
    public void print()
    {
        out.out();
    }
    public static void main(String[] args)
    {
        // 创建OutputFactory
        OutputFactory of = new OutputFactory();
        // 将Output对象传入，创建Computer对象
        Computer c = new Computer(of.getOutput());
        c.keyIn("轻量级Java EE企业应用实战");
        c.keyIn("疯狂Java讲义");
        c.print();
    }
}

/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
public interface Output
{
    // 接口里定义的属性只能是常量
    int MAX_CACHE_LINE = 50;
    // 接口里定义的只能是public的抽象实例方法
    void out();
    void getData(String msg);
}

/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */
public class OutputFactory
{
    public Output getOutput()
    {
        //下面两行代码用于控制系统到底使用Output的哪个实现类。
        return new Printer();
//        return new BetterPrinter();
    }
}

/**
 * Description:
 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */

// 让Printer类实现Output
public class Printer implements Output
{
    private String[] printData = new String[MAX_CACHE_LINE];
    // 用以记录当前需打印的作业数
    private int dataNum = 0;
    public void out()
    {
        // 只要还有作业，继续打印
        while(dataNum > 0)
        {
            System.out.println("打印机打印：" + printData[0]);
            // 把作业队列整体前移一位，并将剩下的作业数减1
            System.arraycopy(printData , 1, printData, 0, --dataNum);
        }
    }
    public void getData(String msg)
    {
        if (dataNum >= MAX_CACHE_LINE)
        {
            System.out.println("输出队列已满，添加失败");
        }
        else
        {
            // 把打印数据添加到队列里，已保存数据的数量加1。
            printData[dataNum++] = msg;
        }
    }
}