[error] unchecked call to add<E> as a member of the raw type of java.util.Vector

[Jon Camilleri]

import java.lang.*;
import java.util.*;
import java.awt.*;

public class TestTwelve
{
	public static void main (String... args)
	{
		StringBuilder sb = new StringBuilder();
		sb.insert(0, 'h');
		sb.insert(1, 'i');
		System.out.println(sb);

		Vector chessFonts = new Vector();
		Font[] allfonts = GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
		int fontcount = 0;

		String myChessPiece = "\u2654";
		for (int j = 0; j < allfonts.length; j++)
		{
			chessFonts.add(allfonts[j].getFontName()); //TODO: Fix this line...
		}
		fontcount++;
	}
}

Error
javac -Xlint TestTwelve.java
TestTwelve.java:21: warning: [unchecked] unchecked call to add(E) as a member of
the raw type java.util.Vector
chessFonts.add(allfonts[j].getFontName());
^
1 warning



"This is the consequence of a somewhat unfortunate limitation of generic types in Java.
For compatibility, the compiler translates all typed array lists into raw ArrayList objects
after checking that the type rules were not violated. In a running program, all array lists
are the same—there are no type parameters in the virtual machine. Thus, the casts
(ArrayList) and (ArrayList<Employee>) carry out identical runtime checks.
There isn’t much you can do about that situation. When you interact with legacy code,
study the compiler warnings and satisfy yourself that the warnings are not serious. "

Core Java Volume 1 (8th Edition) Pg. 211


Chess symbols article at http://en.wikipedia.org/wiki/Chess_symbols_in_Unicode.
Code sourced from an article.

[Matthew Brown]

Yes. What's the question?

You should always use generic types, unless you really have no choice. Change Vector to Vector<String> (or whatever type Font.getFontName() returns) and the warning (warning, not error) will go away.

[Jon Camilleri]

Matthew Brown wrote:Yes. What's the question?

You should always use generic types, unless you really have no choice. Change Vector to Vector<String> (or whatever type Font.getFontName() returns) and the warning (warning, not error) will go away.

It works as follows:

import java.lang.*;
import java.util.*;
import java.awt.*;

public class TestTwelve
{
	public static void main (String... args)
	{
		Vector<String> chessFonts = new Vector<String>();
		Font[] allfonts = GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
		byte fontcount = 0;

		String myChessPiece = "\u2654";
		for (int j = 0; j < allfonts.length; j++)
		{
			chessFonts.add(allfonts[j].getFontName());
		}
		fontcount++;
	}
}

Now I'm just wondering how to read the String myChessPiece, because it will return '?' to the console, so I'm wondering whether there is a problem with the language environment.

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