swing 连接数据库

import java.sql.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class inensshow extends JFrame {


private Connection connection;
private Statement statement;
private ResultSet resultSet;
private ResultSetMetaData rsMetaData;

//GUI变量定义
private JTable table;
private JTextArea inputQuery;
private JButton submitQuery;

public inensshow()
{
//Form的标题
super( "输入SQL语句，按查询按钮查看结果。" );

String url = "jdbc:mysql://localhost:3306/test";
String username = "root";
String password = "000000";
//加载驱动程序以连接数据库
try {
Class.forName( "org.gjt.mm.mysql.Driver" );

connection = DriverManager.getConnection(
url, username, password );
}
//捕获加载驱动程序异常
catch ( ClassNotFoundException cnfex ) {
System.err.println(
"装载 JDBC/ODBC 驱动程序失败。" );
cnfex.printStackTrace();
System.exit( 1 ); // terminate program
}
//捕获连接数据库异常
catch ( SQLException sqlex ) {
System.err.println( "无法连接数据库" );
sqlex.printStackTrace();
System.exit( 1 ); // terminate program
}
//如果数据库连接成功，则建立GUI
//SQL语句
String test="SELECT * FROM about";
inputQuery = new JTextArea( test, 4, 30 );
submitQuery = new JButton( "查询" );
//Button事件
submitQuery.addActionListener(
new ActionListener() {
public void actionPerformed( ActionEvent e )
{
getTable();
}
}
);