public void rebuildTable() {
        for (StoredFile s: sfiles ) {
            String[] data = {
                s.getName(),
                Integer.toString(s.getOriginalSize()), 
                Integer.toString(s.getCompressedSize()),
                Integer.toString((s.getCompressedSize()/s.getOriginalSize())*100),
                s.getCompressorName()};
            rowData.add(new Vector (Arrays.asList(data)));
        }
        this.table = new JTable(rowData,columnNames);
    }


try...

dtm = new DefaultTableModel(colNames,25);
table = new JTable(dtm);
dtm.insertRow(z,oneTableObject);