sizeOf. In Java.

So, got pissed that Java doesn't seem to have anything to help one figure out how much memory individual user sessions are taking up. Having HttpSession support a size() method would be, well, too easy. Anyone have any comments on this? This was cobbled out of something on JGuru.com, and cleaned up a bit.

package util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;


/**
 * Return the size of a Java Object.
 * The object must implement java.io.Serializable
 */
public class SizeOf {

	/**
	 * Return the size of a Java Object, in bytes.
	 * Return -1 if this fails.
	 */
	public static int sizeOf(Object o) throws IOException {

		int counter = -1;

		ByteArrayOutputStream baos = null;
		ObjectOutputStream oos = null;
		try {
			baos = new ByteArrayOutputStream();
			oos = new ObjectOutputStream(baos);
			oos.writeObject(o);
			oos.flush();

			// Serialization adds 4 bytes to an object; remove that.
			counter += baos.toByteArray().length - 4;
		} finally {
			if (oos != null) { try { oos.close(); } catch (Exception e) { ; } }
			if (baos != null) { try { baos.close(); } catch (Exception e) { ; } }
		}

		return counter;
	}

	/**
	 * Return the size of a Java Object, in kbytes.
	 */
	public static int kSizeOf(Object o) throws IOException {
		int temp = sizeOf(o);
		if (temp == -1) {
			return -1;
		} else {
			return temp / 1024;
		}
	}
}