Re: Beginner's Question: "*.java uses unchecked or unsafe operations"

From:

"Oliver Wong" <owong@castortech.com>

Newsgroups:

comp.lang.java.help

Date:

Wed, 04 Oct 2006 13:56:33 GMT

Message-ID:

<l4PUg.12092$N4.4987@clgrps12>

"sunbin" <noSpam@noSpam.com> wrote in message
news:eftt69$ivu$1@reader01.singnet.com.sg...

Hi all

I have read the net and notice this problem is caused by the version of
compiler between 1.5 and 1.4.

I tried to use the follow codes to overcome the warning msg. "uses
unchecked or unsafe operations" but not able to. Please advice. Thanks.

[code]

public class XXX
{
   private ArrayList <Customer> CustDB;
   .....
   .....
   public static void main(String[] args)
   {
       ......
       ......
       ......
       FileInputStream readFile = new FileInputStream("cust.dat");
      ObjectInputStream read = new ObjectInputStream(readFile);

       CustDB = (ArrayList<Customer>)read.readObject();
   }
}

[/code]

I tried to typecast the read object, but yet the warning still exists.
May I know where have I did wrong?

    Specifically, change the cast to:

CustDB = (ArrayList<?>)read.readObject();

    you'll probably have to add some more casts later on in your code in
addition to making this change.

    In general, don't supply generic type arguments in cast expressions.

    - Oliver