java.lang.NullPointerException: inStream parameter is null

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在maven project下使用jdbc或dbcp工具类时会碰到如题异常
通常是因为properties的位置不对造成的
所有的properties文件统一放在src/resources目录下进行管理

工具类

复制代码

private static String name = null;
    private static String url = null;
    private static String username = null;
    private static String password = null;
    static {
        InputStream in = jdbc_utils.class.getClassLoader().getResourceAsStream("jdbc.properties");

Properties pis = new Properties();
        try {
            pis.load(in);
            name=pis.getProperty("name");
            url=pis.getProperty("url");
            username=pis.getProperty("username");
            password=pis.getProperty("password");
            Class.forName(name);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url,username,password);
    }

//4.关闭流
    public static void CloseConnection(Connection con, Statement sta, ResultSet rst) throws SQLException {
        //最好判断一下每个资源是否为null
        con.close();
        sta.close();
        rst.close();
    }

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    private static String name = null;
    private static String url = null;
    private static String username = null;
    private static String password = null;
    static {
        InputStream in = jdbc_utils.class.getClassLoader().getResourceAsStream("jdbc.properties");

        Properties pis = new Properties();
        try {
            pis.load(in);
            name=pis.getProperty("name");
            url=pis.getProperty("url");
            username=pis.getProperty("username");
            password=pis.getProperty("password");
            Class.forName(name);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url,username,password);
    }

    //4.关闭流
    public static void CloseConnection(Connection con, Statement sta, ResultSet rst) throws SQLException {
        //最好判断一下每个资源是否为null
        con.close();
        sta.close();
        rst.close();
    }

测试类

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public class UtilsTest {
    public static void main(String[] args) throws Exception{
        Connection con = dbcp_utils.getConnection();
        String sql = "insert into cusinfo (name, money) VALUES (?,?)";
        PreparedStatement pst = con.prepareStatement(sql);
        pst.setObject(1,"小明");
        pst.setObject(2,"100000");

        int i = pst.executeUpdate();
        if (i>0){
            System.out.println("update success!!");
        }

        dbcp_utils.CloseStream(con,pst,null);
    }
}