给我一个jdbc连接代码

这是一个简单的JDBC连接代码，可以连接到MySQL数据库：

import java.sql.*;

public class JdbcExample {
    public static void main(String[] args) {
        // JDBC driver name and database URL
        String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
        String DB_URL = "jdbc:mysql://localhost:3306/mydatabase";

        // Database credentials
        String USER = "root";
        String PASS = "password";

        Connection conn = null;
        Statement stmt = null;
        try {
            // Register JDBC driver
            Class.forName(JDBC_DRIVER);

            // Open a connection
            System.out.println("Connecting to database...");
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            // Execute a query
            System.out.println("Creating statement...");
            stmt = conn.createStatement();
            String sql = "SELECT id, name, age FROM users";
            ResultSet rs = stmt.executeQuery(sql);

            // Extract data from result set
            while (rs.next()) {
                // Retrieve by column name
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");

                // Display values
                System.out.print("ID: " + id);
                System.out.print(", Name: " + name);
                System.out.println(", Age: " + age);
            }

            // Clean-up environment
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException se) {
            // Handle errors for JDBC
            se.printStackTrace();
        } catch (Exception e) {
            // Handle errors for Class.forName
            e.printStackTrace();
        } finally {
            // Finally block used to close resources
            try {
                if (stmt != null)
                    stmt.close();
            } catch (SQLException se2) {
            }// nothing we can do
            try {
                if (conn != null)
                    conn.close();
            } catch (SQLException se) {
                se.printStackTrace();
            }// end finally try
        }// end try
        System.out.println("Goodbye!");
    }
}

请注意，您需要将“mydatabase”更改为您实际的数据库名称，并将“root”和“password”更改为您的MySQL用户名和密码。