Re: Newbie: Forced to cast when I don't think I need too
Kurt wrote:
Greetings,
Not sure what etiquette is when post code snippets, but here I go;
Given the following 3 classes;
TestDriver
Customer
Center
Note not all methods currently implemented. Feel free to comment on
any nasty programming as I want to learn the correct way to code java
(old procedural programmer!).
Question: In my TestDriver class when I list out the various
CenterId's assigned to a Customer I have to cast it back to a center
before the IDE shows me the method get_CenterId() isn't there a way
for me to get at the get_CenterId() by using the result directly,
something like;
System.out.println("Center ID:" + (Center)i.next().get_CenterId());
The 3 classes follow;
package com.harless.remoteaccess;
no need to bother us with your package details, unless it is relevant to
the problem. I for one don't care to duplicate your directory structure
on my computer. For an excellent guide on what posted code should
contain look at: http://pscode.org/sscce.html For many problems ( not
this one ) the mere act of preparing an SSCCE will help you solve your
problem without posting. But an SSCCE will encourage many more people to
examine your problem than random pieces of uncompilable code will.
import java.util.Calendar;
import java.util.ArrayList;
import java.util.Iterator;
public class TestDriver
{
public static void main(String[] args)
{
////////////////////////////////////////////////////
// assign some objects
////////////////////////////////////////////////////
Customer myCustomer = new Customer();
myCustomer.set_CompanyName("Anasazi Software");
myCustomer.set_StartDate("2008-01-01");
myCustomer.set_EndDate("2100-12-31");
myCustomer.set_CustomerCenter("PHX");
myCustomer.set_CustomerCenter("PHX1");
////////////////////////////////////////////////////
// print some objects
////////////////////////////////////////////////////
listCustomer(myCustomer);
}
public static void listCustomer(Customer tempCustomer)
{
System.out.println("LIST CUSTOMER INFORMATION");
System.out.println("=========================");
System.out.println("Customer Name:"+
tempCustomer.get_CompanyName());
System.out.println("Customer Start Date:" + String.format("
%1$tb %1$te,%1$tY", tempCustomer.get_StartDate()));
Usenet breaks lines as it sees fit. This line break in the middle of
a String will prevent this code from compiling, and immediately lose a
fair portion of the audience you are seeking to help you. Go to
http://pscode.org/twc/ and download Andrew Thompson's text width checker.
System.out.println("Customer End Date:" + String.format("
%1$tb %1$te,%1$tY", tempCustomer.get_EndDate()));
ditto
Iterator i = tempCustomer.get_CustomerCenter().iterator();
this is the "raw" iterator, it has not knowlegde of your generic
declaration. It will always return an Object. What you want is:
Iterator<Center> i = tempCustomer.get_CustomerCenter().iterator();
Center tempCenter;
while (i.hasNext())
{
tempCenter = (Center)i.next();
tempCenter = i.next();
System.out.println("Center ID:" +
tempCenter.get_CenterId());
}
or you could use the new style for loop introduced in Java 1.5
for ( Center tempCenter : tempCustomer.get_CustomerCenter()) {
System.out.println("Center ID:" + tempCenter.get_CenterID());
}
}
}
package com.harless.remoteaccess;
import java.util.ArrayList;
import java.util.Calendar;
public class Customer
class Customer
If you remove public declaration ( and consolidate imports at the top )
all 3 of these classes can line in the same file
{
private String _CompanyName;
private int _Id;
private ArrayList<Center> CustomerCenter = new
> ArrayList<Center>();
private List<Center> CustomerCenter = new ArrayList<Center>();
Unless you are using some feature that is specific to Arraylist, it is
generally considered good practice to declare as a general type and then
allocate as a specific type. This way when Sun releases MagicList in
version 9 you will only need to change the RHS of one statement to get
all the benefits; rather than having to chase down a dozen or more
referenced to the specific type.
private Address MainAddress;
you did not provide the Address class, but String made an easy substitute.
private Calendar _StartDate = Calendar.getInstance();
private Calendar _EndDate = Calendar.getInstance();
public Customer()
{
}
public ArrayList<Center> get_CustomerCenter()
public List<Center> get_CustomerCenter()
see above
{
return CustomerCenter;
}
rest of code delete.