static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";

        static final String DB_URL = "jdbc:mysql://localhost:3306/123?serverTimezone=UTC&characterEncoding=utf-8";

        // 数据库的用户名与密码，需要根据自己的设置

        static final String USER = "root";

        static final String PASS = "heziqaz1234";

        public static void main(String[] args) {

            Connection conn = null;

            Statement stmt = null;

            try{

                // 注册 JDBC 驱动

                Class.forName(JDBC_DRIVER);

                // 打开链接

                System.out.println("连接数据库...");

                conn = DriverManager.getConnection(DB_URL,USER,PASS);

                // 执行查询

                System.out.println(" 实例化Statement对象...");

                stmt = conn.createStatement();

                String sql;

                sql = "SELECT * from jingsai";

                //SELECT * from heziyan where id=1

                // SELECT id, chengji FROM yanwenhui

                ResultSet rs = stmt.executeQuery(sql);

                // 展开结果集数据库

                while(rs.next()){

                    // 通过字段检索

                    String xuhao  = rs.getString("xuhao");

                    String name  = rs.getString("name");

                    String danwei  = rs.getString("danwei");

                    String xueyuan  = rs.getString("xueyuan");

                    String term  = rs.getString("term");

                    String type  = rs.getString("type");

                    // 输出数据

                    System.out.print("ID: " + xuhao);

                    System.out.print(", 身高: " + name);

                    System.out.print(", 体重: " + danwei);

                    System.out.print("ID: " + xueyuan);

                    System.out.print("ID: " + term);

                    System.out.print("ID: " + type);

                    System.out.print("\n");

                }

                // 完成后关闭

                rs.close();

                stmt.close();

                conn.close();

            }catch(SQLException se){

                // 处理 JDBC 错误

                se.printStackTrace();

            }catch(Exception e){

                // 处理 Class.forName 错误

                e.printStackTrace();

            }finally{

                // 关闭资源

                try{

                    if(stmt!=null) stmt.close();

                }catch(SQLException se2){

                }// 什么都不做

                try{

                    if(conn!=null) conn.close();

                }catch(SQLException se){

                    se.printStackTrace();

                }

            }

            System.out.println("Goodbye!");

        }