我有一个 JTextfield 获取要创建的数据库名 JButton 在swing窗体中执行数据库创建操作。问题是当我将值赋给textfield并单击它需要检查整个数据库的按钮时，是否存在与我们赋给新数据库的名称相同的数据库。这意味着需要删除现有数据库，并接受新数据库的给定名称。这是我的密码。

package db1;

    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import java.io.*;
    import java.sql.*;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.SQLException;
    import java.sql.Statement;

  public class Main implements ActionListener
    {
        JTextField txt;
        JButton create;
        JFrame frame;
        JPanel panel;
        JOptionPane jop;
        //Font font = UIManager.getFont("txt.font");
        public Main()
        {
           frame=new JFrame();
           panel=new JPanel();
           txt=new JTextField(10);
           create=new JButton("create");
           create.setBounds(20, 200, 50, 40);

        panel.add(txt);
        panel.add(create);
        create.addActionListener(this);
        frame.add(panel);

           // n.getContentPane().add(new textf());
            frame.setSize(440,310);
            frame.setVisible(true);

        }
        public void actionPerformed(ActionEvent e)
        {
        Connection con = null;
            try{
                Class.forName("com.mysql.jdbc.Driver");
                con = DriverManager.getConnection("jdbc:mysql://localhost:3306/vijay","root","root");
                try{

                                     String database=txt.getText();
                                     Statement st = con.createStatement();
                                     String check=null;
                                    ResultSet rs = con.getMetaData().getCatalogs();
                                    while (rs.next()) {
                                   // System.out.println("" + rs.getString("TABLE_CAT") );
                                     check=rs.getString("TABLE_CAT");
                                     System.out.println(check);

                                    if(database.equals(check))  {I NEED CODE HERE}
                                    {
                                        String query = "DROP DATABASE"+check;
                                        st.executeUpdate(query);
                                    }
                                    else{
                                    st.executeUpdate("CREATE DATABASE "+database);
                    JOptionPane.showMessageDialog(frame,"DATA BASE IS CREATED");

                                        }

                                }
                        }

                catch (SQLException s)
                            {
                    System.out.println(s);
                                //JOptionPane.showMessageDialog(frame,"DATA BASE IS already exist");
                }
            }
            catch (Exception ea){
                       ea.printStackTrace();
            }
        }

        public static void main(String[] args)
        {
            new Main();

        }

    }