Узнать размер объекта положив его в поток ввода вывода

package easybudda.fakesizeof;
 
import java.io.*;
 
public class FakeSizeOf {
    public static void main(String[] args) throws IOException {
        Object[] arr = { new Boolean(true), new Character('ы'), new Integer(13), new Long(69L), new Double(3.14) };
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        ObjectOutputStream objOutStream = new ObjectOutputStream(outStream);
        
        for ( Object obj : arr ) {
            outStream.reset();
            objOutStream.writeObject(obj);
            objOutStream.flush();
            System.out.println(obj.getClass().getSimpleName() + ": " + outStream.size());
        }
        
        System.out.println("\nUsing predefined methods:");
        outStream.reset();
        objOutStream.write(13);
        objOutStream.flush();
        System.out.println("write with int as data: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeBoolean(false);
        objOutStream.flush();
        System.out.println("writeBoolean: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeByte(1);
        objOutStream.flush();
        System.out.println("writeByte: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeChar('ы');
        objOutStream.flush();
        System.out.println("writeChar: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeDouble(3.14);
        objOutStream.flush();
        System.out.println("writeDouble: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeInt(13);
        objOutStream.flush();
        System.out.println("writeInt: " + outStream.size());
        
        outStream.reset();
        objOutStream.writeLong(69L);
        objOutStream.flush();
        System.out.println("writeLong: " + outStream.size());
    }
}