Java设计模式：工厂模式

工厂模式是根据不同的参数来创建对象。其框图为：

package humanfactory;

interface Human
{
    public void Talk();
    public void Walk();
}

class Boy implements Human
{
    @Override
    public void Talk()
    {
        System.out.println("Boy is talking...");
    }
    
    @Override
    public void Walk()
    {
        System.out.println("Boy is walking...");
    }
}

class Girl implements Human
{
    @Override
    public void Talk()
    {
        System.out.println("Girl is talking...");
    }
    
    @Override
    public void Walk()
    {
        System.out.println("Girl is walking...");
    }
}

public class HumanFactory 
{
    public static Human createHuman(String m)
    {
        Human p = null;
        if (m == "boy") p = new Boy();
        else if (m == "girl") p = new Girl();
        
        return p;
    }
    
    public static void main(String[] args) 
    {
     
    }
    
}

java标准库中用工厂模式的有：

java.util.Calendar - getInstance()
java.util.Calendar - getInstance(TimeZone zone)
java.util.Calendar - getInstance(Locale aLocale)
java.util.Calendar - getInstance(TimeZone zone, Locale aLocale)

java.text.NumberFormat - getInstance()
java.text.NumberFormat - getInstance(Locale inLocale)