JDBC固定步骤-java连接MySQL

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!");
        }