在Java中向MySQL添加数据，需要遵循以下步骤：

1、导入JDBC驱动

2、加载并注册JDBC驱动

3、建立数据库连接

4、创建Statement对象

5、执行SQL语句

6、关闭资源

下面是详细的代码示例：

// 1. 导入JDBC驱动
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class AddDataToMySQL {
    public static void main(String[] args) {
        // 2. 加载并注册JDBC驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        // 3. 建立数据库连接
        String url = "jdbc:mysql://localhost:3306/test_db?useSSL=false&serverTimezone=UTC";
        String user = "root";
        String password = "your_password";
        Connection connection = null;
        try {
            connection = DriverManager.getConnection(url, user, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        // 4. 创建Statement对象
        String sql = "INSERT INTO users (username, age) VALUES (?, ?)";
        PreparedStatement preparedStatement = null;
        try {
            preparedStatement = connection.prepareStatement(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        // 5. 执行SQL语句
        String username = "张三";
        int age = 25;
        try {
            preparedStatement.setString(1, username);
            preparedStatement.setInt(2, age);
            int rowsAffected = preparedStatement.executeUpdate();
            System.out.println("插入成功，影响了 " + rowsAffected + " 行。");
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 6. 关闭资源
            if (preparedStatement != null) {
                try {
                    preparedStatement.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

注意：请将your_password替换为实际的MySQL密码。