Failed to create object.Help needed

Question

Hi, I have some program here, the BPDU class and also the RootBridge class. The BPDU class is just a simple class with all the getMethods and the setMethods. For the RootBridge class, it is suppose to connect to the JDBC ODBC database, and create arraylist and retrieve the mac address, priority and also the port id from the database. However, when I tried to create a BPDU object, it gives me an error saying :
--------------------Configuration: j2sdk1.4.2_01 <Default>--------------------
F:\new Project FYP\RootBridge.java:43: BPDU(java.lang.String,double,java.lang.String,int,java.lang.String,java.lang.String) in BPDU cannot be applied to ()
                    BPDU bpdu =new BPDU();
^
1 error
Here are the classes:
BPDU class:
public class BPDU
     private String BridgeIDMac;
     private double BridgeIDPriority;
     private String MsgType;
     private int CostPath;
     private String PortID;
     private String ComputerName;
     public BPDU(String BridgeIDMac, double BridgeIDPriority,String MsgType,int CostPath, String PortID, String ComputerName)
          this.BridgeIDMac=BridgeIDMac;
          this.BridgeIDPriority=BridgeIDPriority;
          this.MsgType=MsgType;
          this.CostPath=CostPath;
          this.PortID=PortID;
          this.ComputerName=ComputerName;
     public String getBridgeIDMac()
          return BridgeIDMac;
     public double getBridgeIDPriority()
          return BridgeIDPriority;
     public String getMsgType()
          return MsgType;
     public int getCostPath()
          return CostPath;
     public String getPortID()
          return PortID;
     public String getComputerName()
          return ComputerName;
     //SET METHODS
     public void setBridgeIDMac(String mac)
          BridgeIDMac=mac;
     public void setBridgeIDPriority(double priority)
          BridgeIDPriority=priority;
     public void setMsgType(String msg)
          MsgType=msg;
     public void setCostPath(int costpath)
          CostPath=costpath;
     public void setPortID(String portid)
          PortID=portid;
     public void setComputerName(String computername)
          ComputerName=computername;
RootBridge Class:
import java.util.*;
import java.sql.*;
import java.io.*;
import java.net.*;
import java.lang.*;
public class RootBridge
     private Connection con;
     private String macaddress;
     private int priority;
     private int portid;
     public RootBridge()
          try
               //ESTABLISH THE JDBC DATABASE CONNECTION
               Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
               con = DriverManager.getConnection("jdbc:odbc:BPDU");
          catch(ClassNotFoundException c)
               System.out.println(c+": JDBC Driver Could Not Be Loaded.");
          catch(SQLException s)
               System.out.println(s+": Database Connection Could Not Be Established.");
     //TO RETRIEVE THE COMPUTER NAME  IN DATABASE
     public ArrayList retrieveComputerName()
          ArrayList arraylist=new ArrayList();
          try
               PreparedStatement p=con.prepareStatement("Select ComputerName from BPDU");
               ResultSet rs= p.executeQuery();
               if(rs.next())
                    //************Here is the error
                                                                                     BPDU bpdu =new BPDU();                    bpdu.setComputerName(rs.getString("ComputerName"));
                    arraylist.add(bpdu);
          catch(SQLException s)
               System.out.println(s+": Could not retrieve computer name from database");
          return arraylist;
     //to get the mac address that belong to the computer
     public BPDU retrieveMacAddress(String computername)
          System.out.println("DB1"+computername);
          try
               PreparedStatement p=con.prepareStatement("Select BridgeIDMAC from BPDU where ComputerName=?" );
               System.out.println("DB2"+computername);
               p.setString(1,computername);
               p.setString(2,computername);
               p.setString(3,computername);
               ResultSet rs=p.executeQuery();
               if(rs.next())
                    macaddress=rs.getString("BridgeIDMAC");
               System.out.println("DB4"+macaddress);
          catch(SQLException s)
               System.out.println(s+": Could not retrieve the mac address from database");
     //to retrieve priority from database
     public BPDU retrievePriority(String computername)
          System.out.println("DB1"+computername);
          try
               PreparedStatement p=con.prepareStatement("Select BridgeIDPriority from BPDU where ComputerName=?" );
               System.out.println("DB2"+computername);
               p.setString(1,computername);
               p.setString(2,computername);
               p.setString(3,computername);
               ResultSet rs=p.executeQuery();
               if(rs.next())
                    priority=rs.getInt("BridgeIDPriority");
               System.out.println("DB4"+priority);
          catch(SQLException s)
               System.out.println(s+": Could not retrieve the priority from database");
     //to retrieve port id from database
     public BPDU retrievePortID(String computername)
          System.out.println("DB1"+computername);
          try
               PreparedStatement p=con.prepareStatement("Select PortID from BPDU where ComputerName=?" );
               System.out.println("DB2"+computername);
               p.setString(1,computername);
               p.setString(2,computername);
               p.setString(3,computername);
               ResultSet rs=p.executeQuery();
               if(rs.next())
                    portid=rs.getInt("PortID");
               System.out.println("DB4"+portid);
          catch(SQLException s)
               System.out.println(s+": Could not retrieve the port id from database");
}Please see //************Here is the error in the Root Bridge class.Help me to solve the problem.Thank You very much

Answer 1

Hi,
The error message means that the BPDU class doesn't have an empty constructor. You must pass the in needed arguments to the BPDU constuctor.
/Kaj