Maven连接mysql

建立一个数据库

-- 创建数据库
CREATE DATABASE test
CHARACTER SET utf8mb4
COLLATE utf8mb4_general_ci;

-- 创建表
CREATE TABLE `tb_poem`  (
  `id` INT(11) AUTO_INCREMENT COMMENT '主键id',
  `title` VARCHAR(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '标题',
  `content` VARCHAR(500) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '内容',
  `create_time` DATETIME NULL DEFAULT NULL COMMENT '创建时间',
  `open_flag` TINYINT(1) NULL DEFAULT NULL COMMENT '状态',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = INNODB AUTO_INCREMENT = 29 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = COMPACT;

-- 插入数据
INSERT INTO `tb_poem` VALUES (26, '第一首诗', '春眠不觉晓，处处闻啼鸟。夜来风雨声，花落知多少。', '2024-08-23 03:03:25', 1);
INSERT INTO `tb_poem` VALUES (27, '信阳学院', '信也到今船，阳后相思老。学上闲愁对满身，院落忘春处。', '2024-08-28 10:03:12', 1);
INSERT INTO `tb_poem` VALUES (28, '信阳学院', '信道生鹧三五，阳关好久真真。学前徊蓑为人闲。院扬香薰宝社。', '2024-09-02 10:24:49', 1);
INSERT INTO `tb_poem` VALUES (29, '信阳学院', '信道心如果，阳华玻万衫。学意云轻雨，院露微凝蝶。', '2024-09-06 02:33:31', 1);

配置maven

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.23</version>
</dependency>

连接maven与数据库

package xyu.com;
import java.sql.Connection;
import java.sql.*;
public class Main {
    public static void main(String[] args) {
        //数据库连接URL，格式为：jdbc:mysql://host:port/databaseName
        String url = "jdbc:mysql://localhost:3306/test";
        // 数据库用户名
        String user = "root";
        // 数据库密码
        String password = "123456";
        Connection conn = null;
        Statement stmt = null;
        try {
            //mysql8.0
            //Class.forName("com.mysql.cj.jdbc.Driver");
            //依赖jar包版本5.x
            // 1 加载MySQL驱动
            Class.forName("com.mysql.jdbc.Driver");
            // 2 建立连接
            conn = DriverManager.getConnection(url, user, password);
            // 3 创建Statement对象执行SQL语句
            stmt = conn.createStatement();
            //4 编写sql语句
            String sql = "SELECT * FROM tb_poem";
            //5 向mysql服务器发送请求，执行SQL查询
            ResultSet rs = stmt.executeQuery(sql);
            System.out.println();
            //6 遍历结果集
            while (rs.next()) {
                //id是整型
                int id = rs.getInt("id");
                //create_time
                Timestamp create_time = rs.getTimestamp("create_time");
                //open_flag
                int open_flag = rs.getInt("open_flag");
                //content
                String content = rs.getString("content");
                //打印结果数据
                System.out.println("ID: " + id + ", create_time: " + create_time + ", open_flag: " + open_flag
                        + ", content: " + content);
            }
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (stmt != null) stmt.close();
                if (conn != null) conn.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }
}