readLine() fix

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.lang.StringBuilder;

class jtest
{
    public static void main(String[] argz)
    {
        try
        {
            File f1 = new File("bintest1");
            File f2 = new File("bintest2");
            if(!f1.exists()) f1.createNewFile();
            if(!f2.exists()) f2.createNewFile();

            StringBuilder sb = new StringBuilder("");
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(f1.getAbsoluteFile()));
            DataOutputStream dos = new DataOutputStream(bos);
            for(int i = 0; i != 256; i++)
            {
                sb.append(String.valueOf((char)i));
                bos.write(i);
            }
            bos.flush();

            dos.writeBytes(sb.toString());
            dos.flush();

            dos.close();
            bos.close();


            BufferedInputStream bis = new BufferedInputStream(new FileInputStream(f1.getAbsoluteFile()));
            DataInputStream dis = new DataInputStream(bis);
            bos = new BufferedOutputStream(new FileOutputStream(f2.getAbsoluteFile()));
            dos = new DataOutputStream(bos);
            StringBuilder result = new StringBuilder("");
            String line = dis.readLine();
            while (line != null)
            {
                result.append(line);
                line = dis.readLine();
                if (line != null)
                {
                    result.append("\n");
                }
            }
            dis.close();
            bis.close();

            String str = result.toString();

            dos.writeBytes(str);

            bos.close();

        }
        catch(IOException ioex)
        {
            ioex.printStackTrace();
        }
    }
}