public Connection getConnection() throws Exception {String driver = "com.mysql.jdbc.Driver";String url = "jdbc:mysql://localhost:3307/shijian";String user = "root";String password = "1234";Class.forName(driver);Connection connection = DriverManager.getConnection(url, user, password);return connection;//System.out.println(connection);
    }//关闭public  void Close(ResultSet rs, Statement statement, Connection conn) {if (rs != null) {try {rs.close();} catch (SQLException e) {e.printStackTrace();}}if (statement != null) {try {statement.close();} catch (SQLException e) {e.printStackTrace();}}if (conn != null) {try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}

    @Testpublic void testPreparedStatementjdbc(){Connection connection = null;PreparedStatement preparedStatement = null;try {connection = getConnection();String sql = "insert into student(sname,sclass) values(?,?)"; preparedStatement = (PreparedStatement) connection.prepareStatement(sql); preparedStatement.setString(1, "lisi");preparedStatement.setInt(2, 123456);//不要传入SQL语句
            preparedStatement.executeUpdate();} catch (Exception e) {e.printStackTrace();}finally {Close(null, preparedStatement, connection);}}

    @Testpublic void testResultMeteData(){Connection connection = null;PreparedStatement statement  =null;ResultSet resuleset = null;try {String sql = "select * from student where id = ?";connection = testGetConnection();statement = (PreparedStatement) connection.prepareStatement(sql);statement.setInt(1, 2);resuleset = statement.executeQuery();//1.得到ResultSetMetaData对象ResultSetMetaData rsmd = (ResultSetMetaData) resuleset.getMetaData();//2.打印每一列的列名Map<String,Object> values = new HashMap<String,Object>();while(resuleset.next()){for(int i = 0; i < rsmd.getColumnCount();i++){String c = rsmd.getColumnLabel(i +1);Object ovalue = resuleset.getObject(c);//System.out.println(c + "--" + ovalue);
                    values.put(c, ovalue); }Class clazz = Student.class;Object object = clazz.newInstance();for(Map.Entry<String, Object> entry: values.entrySet()){String sid = entry.getKey();String sname = (String) entry.getValue();System.out.println( sid + "--" + sname);}
            }} catch (Exception e) {e.printStackTrace();}finally {Close(resuleset, statement, connection);}}