JAVA之读取properties时路径的注意问题

v=com.luhy.test.Hello

package com.luhy.test;
public class Hello {
	public void run(){
		System.out.println("Hello");
	}
}

package com.luhy.test;
import java.util.Properties;
public class ReadProperties {
	public static void main(String[] args) throws Exception{
		String filename = "com/luhy/test/ReadProperties.properties";
		Properties props = new Properties();
		props.load(ReadProperties.class.getClassLoader().getResourceAsStream(filename));
		String h = props.getProperty("v");
		Object o = Class.forName(h).newInstance();
		Hello hello = (Hello)o;
		hello.run();
	}
}

props.load(ReadProperties.class.getClassLoader().getResourceAsStream(filename));

Properties properties = new Properties();  
InputStream inputStream = this.getClass().getResourceAsStream("/menu.properties");  
properties.load(inputStream );  
System.out.println(properties.getProperty("a"));  

Properties properties = new Properties();  
InputStream inputStream = this.getClass().getResourceAsStream("/menu.properties");  
BufferedReader bf = new BufferedReader(new    InputStreamReader(inputStream));  
properties.load(bf);  
System.out.println(properties.getProperty("a"));  

/**
 * 读取配置文件Properties
 * 
 * @author xl
 *
 */
public class PropertiesUtil {
    private PropertiesUtil() {
    }
    private static class SingletonHolder {
        private final static PropertiesUtil instance = new PropertiesUtil();
    }
    public static PropertiesUtil getInstance() {
        return SingletonHolder.instance;
    }
    /**
     * 读取key字段，配置文件在classes根路径下xx.properties，在子路径下xx/xx.properties
     * 
     * @param file
     * @param key
     * @return
     */
    public String read(String file, String key) {
        InputStream in = getClass().getClassLoader().getResourceAsStream(file);
        BufferedReader bf = new BufferedReader(new InputStreamReader(in)); 
        Properties prop = new Properties();
        String value = "";
        try {
            prop.load(bf);
            value = prop.getProperty(key);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return value;
    }
}

/**
     * 获取properties文件中存放的数据
     * 
     * @param req
     * @param resp
     * @return
     * @throws Exception
     */
    @RequestMapping(value = "/getPropertiesData")
    @ResponseBody
    public Map<String, Object> getPropertiesData(HttpServletRequest req, HttpServletResponse resp) throws Exception {
        Map<String, Object> returnMap = new HashMap<String, Object>();
        // 获取请求参数
        String key = (String) req.getParameter("key");
        String file = (String) req.getParameter("file");
        // 从配置文件读取key对应的value
        String value = PropertiesUtil.getInstance().read(file, key);
        returnMap.put("data", value);
        // 解析返回结果
        return returnMap;
    }