关于对话框弹出两次的问题

[weixin_38356833]

	@Override
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
		if(e.getSource()==btn1){
			sid = "401";
		}
		if(e.getSource()==btn2){
			sid = "402";
		}
		if(e.getSource()==btn3){
			sid = "403";
		}
		if(e.getSource()==btn4){
			sid = "404";
		}
		if(e.getSource()==btn5){
			sid = "405";
		}
		if(e.getSource()==btn6){
			sid = "406";
		}
		if(e.getSource()==btn7){
			sid = "407";
		}
		if(e.getSource()==btn8){
			sid = "408";
		}
		if(e.getSource()==btn9){
			sid = "409";
		}
		if(e.getSource()==btn10){
			sid = "410";
		}
		if(e.getSource()==btn11){
			sid = "411";
		}
		if(e.getSource()==btn12){
			sid = "412";
		}
		String url = "jdbc:odbc:hosiptal";
		String SQL = "SELECT * FROM Patient";
		Connection conn;
		PreparedStatement sql;
		ResultSet rs;
		try {
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		} catch (ClassNotFoundException e2) {
			// TODO: handle exception
		}
		try {
			conn = DriverManager.getConnection(url);
			sql = conn.prepareStatement(SQL);
			rs = sql.executeQuery();
//			while(rs.next()){
			if(rs.next()){
				String sid1 = rs.getString(12);
				if(sid.equals(sid1)){
					JOptionPane.showMessageDialog(null, "该病房已满！");

				}
				else{
					JOptionPane.showMessageDialog(null, "该病房空闲！");
					this.setVisible(false);
				}
			}
		} catch (SQLException e2) {
			// TODO: handle exception
			e2.printStackTrace();
		}
	}
}

一直弹出两次该病房已满，或者弹出两次该病房空闲，第二次弹出时，点确定就不弹出来了。