java通过配置文件jdbc.properties链接Oracle数据库工具类

package resources;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.sql.Driver;import java.sql.SQLException;import java.util.Properties;public class DbUtil {      public static Connection getConnection(){          String driverClass = null;          String jdbcUrl = null;          String user = null;          String password = null;          //读取类路径下的 jdbc.properties 文件，我的配置文件放在src包下        InputStream in = DbUtil.class.getClassLoader().getResourceAsStream("jdbc.properties");          Properties properties = new Properties();          try {            properties.load(in);        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }          driverClass = properties.getProperty("driver");          jdbcUrl = properties.getProperty("jdbcUrl");          user = properties.getProperty("username");          password = properties.getProperty("password");          Driver driver = null;        try {            driver = (Driver) Class.forName(driverClass).newInstance();        } catch (InstantiationException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (IllegalAccessException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (ClassNotFoundException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }          Properties info = new Properties();        info.put("user", user);        info.put("password", password);          //通过 Driver 的 connect 方法获取数据库连接.           Connection connection = null;        try {            connection = driver.connect(jdbcUrl, info);        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }          System.out.println("----The database is connected----");        return connection;      } }jdbc.properties内容如下：driver=oracle.jdbc.driver.OracleDriver#jdbcUrl=jdbc\:oracle\:thin\:@10.91.4.102\:1521\:orcljdbcUrl=jdbc\:oracle\:thin\:@127.0.0.1\:1521\:orclusername=cp2password=cp2test//调用方法public static void main(String[] args) {        String id = "111111";        String gread = "3";        List<Student> sList = new ArrayList<Student>();        Connection con = DbUtilCR.getConnection();        PreparedStatement pre = null;        ResultSet result = null;        String sql = "select s.name,s.age from student s where s.id=? and s.gread=?";        try {            pre = con.prepareStatement(sql);            pre.setString(1, id);//传参数学号            pre.setString(2, gread);//传参数年级            result = pre.executeQuery();            System.out.println("执行SQL为：["+sql+"]");            System.out.println("参数为：["+id+","+gread+"]");            while (result.next()){                Student st = new Student();                st.setName(result.getString("name"));//与查询出的字段或者别名保持一致                st.setAge(result.getString("age"));                sList.add(st);            }        } catch (SQLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }          for (int i = 0;i<sList.size();i++) {            System.out.println("姓名："+sList.get(i).getName()+"\t年龄："+sList.get(i).getAge());        }    }