java向mysql输入中文

CREATE DATABASE mydatabase CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
CREATE TABLE mytable (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

String url = "jdbc:mysql://localhost:3306/mydatabase?useUnicode=yes&characterEncoding=UTF-8";
Connection conn = DriverManager.getConnection(url, "username", "password");

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class MySQLInsertExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase?useUnicode=yes&characterEncoding=UTF-8";
        String user = "username";
        String password = "password";

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            String sql = "INSERT INTO mytable (name) VALUES (?)";
            try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
                pstmt.setString(1, "张三");
                pstmt.executeUpdate();
                System.out.println("数据插入成功！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}