design_model（17）state

1.状态模式

根据其内部状态改变其行为

2.实例

public interface State {
	void handle();
}

public class GoodState implements  State{

	@Override
	public void handle() {
		System.out.println("goodstate");
	}
   
}

public class Context {
	private State state;

	public void setState(State s) {
		System.out.println("修改状态！");
		state = s;
		state.handle();
	}
}

public class Client {
   public static void main(String[] args) {
	  Context context = new Context();
	  context.setState(new  GoodState());
   }
}