Conversion of Arrays to List - code causing compiler error

[Sandra Bachan]

Hello,

Below is code from Chapter 7, Sierra/Bates

import java.util.*;

class Conversion{
	public static void main(String[] args){
		String[] sa = {"one", "two", "three", "four"};
		List sList = Array.asList(sa);
		System.out.println("size " + sList.size());
		System.out.println("idx2 " + sList.get(2));
		
		sList.set(2, "six");
		sa[1] = "five";
		for (String s : sa)
			System.out.print(s + " ");
		System.out.println("\ns1[1] " + sList.get(1));
	}
}

When I compile, with javac Conversion.java I get:

Conversion.java:6: cannot find symbol
symbol : variable Array
location: class Conversion
List sList = Array.asList(sa);
^
Note: Conversion.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error

When I recompile with javac -Xlint Conversion.java I get:

Conversion.java:6: cannot find symbol
symbol : variable Array
location: class Conversion
List sList = Array.asList(sa);
^
Conversion.java:10: warning: [unchecked] unchecked call to set(int,E) as a member of the raw type java.util.List
sList.set(2, "six");
^
1 error
1 warning


I pulled this code from the book, and imported the proper libraries (I think). Please guide.

[Henry Wong]

I think you want the Arrays class -- and not the Array class.

Henry

[Sandra Bachan]

Henry Wong wrote:
I think you want the Arrays class -- and not the Array class.

Henry

I made the correction and still get this warning:

Note: Conversion.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

What are they talking about because I haven't read about it in Sierra/Bates?

How do I fix this?

Nonetheless, my code runs and outputs as shown in the book

[Soumya Ranjan Mohanty]

  List<String> sList = Arrays.asList(sa);  

I think now you won't get such warning. Now your list is Generic and type safe, It will only take String otherwise compilation error.

[Abimaran Kugathasan]

If you are using version after JDK1.5, it will give those warnings. It's no a problem. Go ahead... And, if you generic types of object and methods, then, there won't be any warnings....

[Bert Bates]

Hey Sandra,

Hang in there - you're a few pages away from a discussion of those pesky compiler warnings you're starting to experience

[Sandra Bachan]

@ Bert: Yes, I did come across the explanation for those compiler errors and it makes sense


@ Soumya: Now I fixed the code and now the compiler is silent.