第八章 设计模式

public class Application {
public static void main(String argv[]) {
	 	GetShow k=new GetShow();
	 	
	    k.setStrategy(new ConcreteStrategyA());
	 	A a=new A();
	 	a.settype("策略1:从a到z打印\n");
	 	System.out.printf("%s",a.gettype());
	 	k.getshow();
	 	
	 	
	    k.setStrategy(new ConcreteStrategyB());
	 	A b=new A();
	 	b.settype("\n策略2:从a到z打印\n");
	 	System.out.printf("%s",b.gettype());
	 	k.getshow();
	 	
	 	 k.setStrategy(new ConcreteStrategyC());
		 A c=new A();
		 c.settype("\n策略3:大写字母从a到z打印\n");
		 System.out.printf("%s",c.gettype());
		 k.getshow();
	
}
}
class A{
	String type;
	public void settype(String s) {
		type=s;
	}
	public String gettype() {
		return type;
		
	}
}//此类可无，不重要

public  class ConcreteStrategyA implements Strategy{
	public void show() {
	       char cStart='a',cEnd='z';
	         for(char c=cStart;c<=cEnd;c++){
	           System.out.print(" "+c);
	         }}
}

public class ConcreteStrategyB implements Strategy {
	public void show() {
	       char cStart='z',cEnd='a';
	         for(char c=cStart;c>=cEnd;c--){
	           System.out.print(" "+c);
	         }}
}

public class ConcreteStrategyC implements Strategy {
	public void show() {
		for(int i = 1;i<=26;i++){
	         System.out.print(Character.toUpperCase((char)(96+i)));//大写
	      }	
	}
}

public class GetShow {
    Strategy strategy;
    public void setStrategy(Strategy strategy) {
    	this.strategy=strategy;
    }
    public void getshow() {
    strategy.show();//直接调用即可，书上的通过return
    	}
	}

public interface Strategy {
 public void show();
}