一個java實現的簡單工廠模式

定義接口

package com.ttjslbz.factory;

public interface Api {
	void functionA();
}

定義實現A

public class ImplA implements Api {

	@Override
	public void functionA() {
		// TODO Auto-generated method stub
		System.out.print("This is implement A for Api");
	}

}

定義實現B

public class ImplB implements Api {


	@Override
	public void functionA() {
		// TODO Auto-generated method stub
		System.out.print("This is implement B for Api");
	}
}

工廠

public class Factory {
	
	// 預加載需要讀取的配置文件
		private static Properties p;
		static {
			InputStream in = Factory.class
					.getResourceAsStream("Factory.properties");
			;
			p = new Properties();
			try {
				p.load(in);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} finally {
				try {
					in.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		
	public static Api creatApi(String propertie) {
		Api	api = null;
		try {
		 api = (Api)Class.forName(p.getProperty(propertie)).newInstance();
		}catch(InstantiationException e){
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return api;


	}
	
}

客戶端

public class Client {
	public static void main(String[] args) {
		Api apiA = Factory.creatApi("IMPLEMENTA");
		apiA.functionA();
		Api apiB= Factory.creatApi("IMPLEMENTB");
		apiB.functionA();
		Api apiC = Factory.creatApi("IMPLEMENTC");
		apiC.functionA();
	}
}