uncheked or unsafe operations

[akashvinay vinaydeo]

hey
while comiling the following code from Head First servlets & JSP page no.82

    
package com.example.model;
import java.util.*;
 
public class BeerExpert
{
public List getBrands(String color) 
{
List brands = new ArrayList();

if(color.equals("amber"))
{
brands.add("Jack Amber");
brands.add("Red Moose");
}
else 
{
brands.add("Jail Pale Ail");
brands.add("Gout Stout");
}

return(brands);
}
}

i am getting following error

BeerExpert.java uses unsafe or unchecked operations
Recompile with -Xlint:unchked for details

please help:
[e-mail]

[Campbell Ritchie]

Welcome to JavaRanch

That's not an error, but a warning. If you recompile with javac -Xlint:unchecked BeerExpert.java it will tell you what it thinks the problem is.
What it means is that there is a risk of your putting something into the Lists and trying to get it out as a different type, in which case there will be a ClassCastException thrown.
That sort of warning only started appearing when Java5 was introduced in Autumn 2004. It can be obviated by using generics, but that is probably too advanced a topic for the earlier pages of a Head First book. By the way: was that book printed before Autumn 2004?