在其他類中聲明使用變量

好吧我有點停留在一個地步，我不得不問在其他類中聲明使用變量

我有2類稱爲主和數據庫連接

在我DBCONNECT我所有的neccesary方法連接到一個數據庫，並在我的主類我創建的GUI，但問題是我宣佈我的主要變量（因爲它們由文本框代表），現在想要在我的dbconnect類中使用它們

我的dbconnect類看起來像跟隨

import javax.swing.*; 
import java.sql.*; 

public class DBCONNECT 
{ 
Connection conn; 
public void connect() 
{ 

    try 
    { 
     Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 
     conn = DriverManager.getConnection("jdbc:odbc:DriverConn"); 
    } 
    catch(Exception se) 
    { 
     JOptionPane.showMessageDialog(null, "Error: Could not load driver " + se.getMessage()); 
    } 
} 
public void dissconect() 
{ 
    try 
    { 
     conn.close(); 
    } 
    catch(Exception e) 
    { 
     JOptionPane.showMessageDialog(null, "Error : Could not close Database " + e.getMessage()); 
    } 
} 
public void writeToDB() 
{ 
    try 
    { 
     MAIN main = new MAIN(); 
     Statement st = conn.createStatement(); 
     String command1 = ("INSERT INTO Drivers (IDNumber, FirstName, LastName) VALUES" + drivID + FName + LName); 
     String command2 = "INSERT INTO Offences(IDNumber, SpeedLimit, DriverSpeed, SeatBelt, DrunkenDriving, DriversLicense) VALUES" + drivID + intspeed + intDSpeed + strSeat + strDrunk + strLicense; 
     String command3 = "INSERT INTO DriverPoints(IDNumber, Points) VALUES" + drivID + intpoints; 
    } 
} 
public ResultSet select(String sql) 
{ 
    try 
    { 
     Statement st = conn.createStatement(); 
     return st.executeQuery(sql); 
    } 
    catch(Exception e) 
    { 
     JOptionPane.showMessageDialog(null, "Error: Could not read from database"); 
    } 
    return null; 
} 
public int change (String sql) 
{ 
    try 
    { 
     Statement st = conn.createStatement(); 
     return st.executeUpdate(sql); 
    } 
    catch(Exception e) 
    { 
     JOptionPane.showMessageDialog(null, "Error: Could not Update Database"); 
    } 
    return -1; 
} 
}

有人可以幫忙嗎？

來源

2012-10-22 Jaun Lloyd

將它們作爲參數傳遞？ - 哪些變量特別？ – John3136

這些：+ drivID + intspeed + intDSpeed + strSeat + strDrunk + strLicense;他們都在我的主要貴班 –