MySQL 篇- Java 连接 MySQL 数据库并实现数据交互

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
 
public class MySQLAccess {
    private Connection connect = null;
    private PreparedStatement preparedStatement = null;
    private ResultSet resultSet = null;
 
    public void connectDB() {
        try {
            // 加载MySQL JDBC驱动程序
            Class.forName("com.mysql.cj.jdbc.Driver");
            // 设置数据库连接字符串，用户名和密码
            String connectionString = "jdbc:mysql://localhost:3306/testdb?user=root&password=root";
            // 建立连接
            connect = DriverManager.getConnection(connectionString);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public void insertData() {
        try {
            String sql = "INSERT INTO users (name, email) VALUES (?, ?)";
            preparedStatement = connect.prepareStatement(sql);
            preparedStatement.setString(1, "John");
            preparedStatement.setString(2, "john@example.com");
            preparedStatement.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public void retrieveData() {
        try {
            String sql = "SELECT id, name, email FROM users";
            preparedStatement = connect.prepareStatement(sql);
            resultSet = preparedStatement.executeQuery();
            while (resultSet.next()) {
                System.out.println("ID: " + resultSet.getInt("id") + ", Name: " + resultSet.getString("name") + ", Email: " + resultSet.getString("email"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
        MySQLAccess mySQLAccess = new MySQLAccess();
        mySQLAccess.connectDB();
        mySQLAccess.insertData();
        mySQLAccess.retrieveData();
    }
}

这段代码展示了如何使用Java连接MySQL数据库，并实现数据的插入和查询操作。首先加载JDBC驱动，然后建立连接，接着执行SQL语句进行数据的插入和查询。这是一个简单的例子，展示了如何在Java中使用JDBC操作数据库的基本步骤。