《有些模式》- 服务提供者

 /**
 * 服务接口
 * @author Macrotea
 *
 */
public interface Service {
	public abstract void doSomeService();
}

 

 

/**
 * 服务提供者接口
 * @author Macrotea
 *
 */
public interface Provider {
	Service newService();
}

 

 

public class ServiceFactory {
	private static final String DEFAULT_PROVIDER_NAME = "<def>";
	private static final HashMap<String, Provider> providerMap = new HashMap<String, Provider>();
	
	/*注册服务提供者*/
	public static void rigiserProvider(Provider p){
		providerMap.put(DEFAULT_PROVIDER_NAME, p);
	}
	public static void rigiserProvider(String name,Provider p){
		providerMap.put(name, p);
	}
	
	/*获得服务*/
	public static Service newInstanse() throws Exception{
		return newInstanse(DEFAULT_PROVIDER_NAME);
	}
	public static Service newInstanse(String name){
		Provider p=providerMap.get(name);
		if(p==null){
			throw new IllegalArgumentException("系统根据名字没有找到提供者出错:");
		}
		return p.newService();
	}
}