c3p0连接池问题

Question

    private static Properties pro;
    static {   
        try {
         pro.load(Pool.class.getResourceAsStream("config.properties"));
              ds = new ComboPooledDataSource();   
              ds.setDriverClass("oracle.jdbc.driver.OracleDriver");  // 参数由 Config 类根据配置文件读取
              ds.setJdbcUrl("jdbc:oracle:thin:@127.0.0.1:1521:HYHDB");   
              ds.setUser("scott");   
              ds.setPassword("huyahui");   
              ds.setMaxPoolSize(200);   
              ds.setMinPoolSize(20);   
        } catch (PropertyVetoException e) {   
            e.printStackTrace();   
        }
    }  我想在静态块中加载配置文件,文件路径没有问题,出现错误
java.lang.ExceptionInInitializerError
Caused by: java.lang.NullPointerException
at DBUtils.Pool.<clinit>(Pool.java:23)
Exception in thread "main" 
错误指向         //pro.load(Pool.class.getResourceAsStream("config.properties"));这行