Re: throwing exceptions on instantiation

On Thu, 08 May 2008 22:04:19 -0700, Knute Johnson wrote:
[...]
> Just re-throw the exception.

Let's say Guest throws a DataException to FileUtils.newGuest(), which 
then throws that DataException to FileUtils.loadGuest(), which means that 
loadGuest() needs to try newGuest() ?

If I'm misunderstanding how it's should work, or the standard approach, 
please let me know. 





thufir@[EMAIL PROTECTED]
 
thufir@[EMAIL PROTECTED]
 cat src/a00720398/util/
FileUtil.java
/**
 * FileUtil.java
 */

package a00720398.util;

im****t java.util.*;
im****t java.io.*;
im****t a00720398.data.*;

public abstract class FileUtil {

        public static List<String> parseGuestString (String string){

                System.out.println("\n\n\n********\n");

                List<String> guestData = new ArrayList<String>();
                Scanner lineScanner = new Scanner(string);
                while (lineScanner.hasNext()){
                        String token = lineScanner.next();
                        guestData.add(token);
                        System.out.println("\n\ntoken\t\t" + token);
                }
                return guestData;
        }

        public static Guest newGuest(String string) {
                List<String> guestData = parseGuestString(string);

//              try {
                        Guest guest = new Guest(guestData);
                        return guest;
//              catch (Exception e) {
//                      e.printStackTrace();
//              }
//              return new Guest();
        }

        public static List<Guest> loadGuests(File file){
                List<Guest> guests = new ArrayList<Guest>();

                try {
                        Scanner scanner = new Scanner(file);
                        while (scanner.hasNextLine()) {
                                String line = scanner.nextLine();
                                Scanner lineScanner = new Scanner(line);
                                lineScanner.useDelimiter("\n");
                                while (lineScanner.hasNextLine()) {
                                        String oneLine = lineScanner.next
();
                                        Guest guest = newGuest(oneLine);
                                }
                        }
                } catch (FileNotFoundException e) {
                        e.printStackTrace();
                }
                return guests;
        }
}
thufir@[EMAIL PROTECTED]
 
thufir@[EMAIL PROTECTED]
 cat src/a00720398/data/Guest.java
package a00720398.data;

im****t java.util.*;

im****t a00720398.data.*;
im****t a00720398.util.*;


public class Guest {

        private int id = 0;

        private String
                lastName = "foo",
                firstName = "foo",
                phoneNumber = "foo",
                emailAddress = "foo@[EMAIL PROTECTED]
";

        private Address address;

        public Guest() {}

        public Guest(List<String> data)/* throws DataException */ {
//              if (data.size() != 5){throw new DataException("expected 5 
elements, got:\t\t" + data.size());}

//              try {
                        id = Integer.parseInt(data.get(0).trim());
//              } catch (Exception e) { //what kind of Exception is this?
//                      e.printStackTrace();
//                      throw new DataException(e.getMessage());
//              }

                lastName = data.get(1);
        }


        public int getID
()                                                                 
{return id;}
        //private setID(int 
id)                                                            {this.id = 
id;}  //never change an ID

        public String getLastName
()                                                        {return 
lastName;}
        public void setLastName(String 
lastName)                                {this.lastName = lastName;}

        public String getFirstName
()                                                       {return 
firstName;}
        public void setFirstName(String firstName)                      
{this.firstName = firstName;}

        public Address getAddress
()                                                        {return 
address;}
        public void setAddress(Address address)                         
{this.address = address;}

        public String getPhoneNumber
()                                                  {return phoneNumber;}
        public void setPhoneNumber(String phoneNumber)          
{this.phoneNumber = phoneNumber;}

        public String getEmailAddress
()                                                 {return emailAddress;}
        public void setEmailAddress(String emailAddress)        
{this.emailAddress = emailAddress;}


        public String toString (){
                return
                        "\n\n\nGUEST RECORD\n" + "-----------\n" +
                        "\nid:\t\t" + getID() +
                        "\nfirst name:\t" + getFirstName() +
                        "\nlast name:\t" + getLastName() +
                        "\nemail address:\t" + getEmailAddress() +
                        address.toString();
        }
}
thufir@[EMAIL PROTECTED]
 
thufir@[EMAIL PROTECTED]
 




thanks,

Thufir