java 在properties文件手动加入了值 取不出来

为什么之前的值能取出来 新加的取出是空 需要刷新么 都是getProperties（“key”）取得？

配置文件读取的话：

 <context:property-placeholder location="classpath:jdbc.properties"/>

java读取：

private static String confile = "jdbc.properties";
private static Properties p = null;
tatic {
        InputStream inputStream = null;
        try {
            p = new Properties();
            confile = DBHelper.class.getClassLoader().getResource("").getPath() + confile;
            File file = new File(confile);
            inputStream = new BufferedInputStream(new FileInputStream(file));
            p.load(inputStream);
            Class.forName(p.getProperty("driver"));
        } catch (Exception e) {

        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {

                    e.printStackTrace();
                }
            }
        }

    }