工厂解耦

工厂

package cn.tedu.factory;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Properties;

public class BasicFactory {
	private static BasicFactory factory = new BasicFactory();
	private static Properties prop = new Properties();

	private BasicFactory() {
	}

	public static BasicFactory getFactory() {
		return factory;
	}

	static {
		try {
			String path = BasicFactory.class	.getClassLoader()
					.getResource("conf.properties").getPath();
			prop.load(new FileInputStream(new File(path)));
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}

	/**
	 * 创建各种实例
	 */
	public <T> T getInstance(Class<T> clazz) {
							//UserDao UserService
		try {
			String className = prop.getProperty(clazz.getSimpleName());
			//根据clazz.getSimpleName()接口名，配置文件中获取实现类的全路径名
			Class clz = Class.forName(className);
			return (T)clz.newInstance();
		} catch (Exception e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}
}