代码总是报错：Exception in thread "main"java.lang.ExceptionInInitializerError请问怎么解决？

Question

问题遇到的现象和发生背景

代码总是报错：Exception in thread "main" java.lang.ExceptionInInitializerError和java.lang.NullPointerException，好像是静态初始化块中出现了异常的时候出现。请问怎么解决？

用代码块功能插入代码，请勿粘贴截图

package itcast.util;


import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
import java.sql.*;
import java.util.Properties;

public class jdbcUtils {
    private static String url;
    private static String username;
    private static String password;
    private static String driver;

    //获去资源
    static {
        try {
            //创建Properties集合类
            Properties pro = new Properties();
            ClassLoader classLoader = jdbcUtils.class.getClassLoader();
            URL res = classLoader.getResource("jdbc.properties");
            String path = res.getPath();
            //加载文件
            pro.load(new FileReader(path));
            //获去数据赋值
            url= pro.getProperty("url");
            username=pro.getProperty("user");
            password=pro.getProperty("password");
            driver=pro.getProperty("driver");
            Class.forName(driver);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }


    }
    //获取连接对象
    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url, username, password);
    }
    //释放资源
    public static void close(ResultSet rs, Statement stmt, Connection conn){
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }
}
*/

运行结果及报错内容

Answer 1

从报错原因以及以及代码可能是以下代码有问题：

// 此行获取的实例：res 为null ,因此下一步才会报空指针异常
URL res = classLoader.getResource("jdbc.properties");