JDBC连接Oracle数据库

public void makeJDBC() throws SQLException {

        Connection conn = null;

        PreparedStatement pstmt;

        ResultSet rs;

        try {

            Class.forName("oracle.jdbc.driver.OracleDriver");

        } catch (ClassNotFoundException e){

            System.out.println("驱动出错");

            e.printStackTrace();

        }

        try {

            conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:HelloWorld", "root", "root");

            pstmt = conn.prepareStatement("select * from HelloWorld");

            rs = pstmt.executeQuery();

            while (rs.next()) {



            }

        } finally {

            if(conn != null) {

                conn.close();

            }

            //pstmt.close();

            //rs.close();

        }

    }

finally中，conn的关闭必须放在第一个，而pstmt和rs是否有必要close()视具体情况而定。