1.在使用PdfPTable畫表格時，表單水平居中使用PdfPCell的setHorizontalAlignment(Element.ALIGN_CENTER)即可；

2.垂直居中使用setVerticalAlignment(Element.ALIGN_MIDDLE)同時設定setUseAscender(true)、setUseDescender(true)；

3.改變字型樣式和大小可以使用如下方法：

Font font = new Font(Font.NORMAL, 8)

Paragraph paragraph = new Paragraph(value,font)

4.改變表格的預設寬度

table.setTotalWidth(500);
        table.setLockedWidth(true);

5.繪畫複雜表格時可以使用巢狀表格

將一個PdfPTable物件放到PdfPCell物件中，而後再將PdfPCell物件放到外層表格中例項如下

public static void aaa(Document document){
        try{
            Font font = new Font(Font.NORMAL, 8);
            Font headFont = new Font(Font.NORMAL, 8, Font.BOLD);
            PdfPTable table = new PdfPTable(4);
            table.setTotalWidth(300);
            table.setLockedWidth(true);
            table.setWidths(new float[]{3, 11, 15, 9});
            PdfPCell cell= new PdfPCell(new Paragraph("NO", headFont));
            cell.setHorizontalAlignment(Element.ALIGN_CENTER);
            table.addCell(cell);
            cell = new PdfPCell(new Paragraph("Config",headFont));
            cell.setHorizontalAlignment(Element.ALIGN_CENTER);
            table.addCell(cell);
            cell = new PdfPCell(new Paragraph("ConfigUnitPrice",headFont));
            cell.setHorizontalAlignment(Element.ALIGN_CENTER);
            table.addCell(cell);
            cell= new PdfPCell(new Paragraph("TotalPrice", headFont));
            cell.setHorizontalAlignment(Element.ALIGN_CENTER);
            table.addCell(cell);
            cell = new PdfPCell(new Paragraph(String.valueOf(1),font));
            cell.setVerticalAlignment(Element.ALIGN_MIDDLE);
            cell.setUseAscender(true);
            cell.setUseDescender(true);
            table.addCell(cell);
            //巢狀表格
            PdfPTable configTable = new PdfPTable(1);
            cell = new PdfPCell(new Paragraph("CPU(core):"+2.0, font));
            configTable.addCell(cell);
            cell= new PdfPCell(new Paragraph("Mem(M):"+2048, font));
            configTable.addCell(cell);
            cell= new PdfPCell(new Paragraph("Disk(G):"+500, font));
            configTable.addCell(cell);
            cell = new PdfPCell(configTable);
            table.addCell(cell);
            //巢狀表格
            PdfPTable unitPriceTable = new PdfPTable(1);
            cell= new PdfPCell(new Paragraph("300", font));
            unitPriceTable.addCell(cell);
            cell= new PdfPCell(new Paragraph("200", font));
            unitPriceTable.addCell(cell);
            cell= new PdfPCell(new Paragraph("300", font));
            unitPriceTable.addCell(cell);
            cell = new PdfPCell(unitPriceTable);
            table.addCell(cell);
            cell= new PdfPCell(new Paragraph("800", font));
            cell.setVerticalAlignment(Element.ALIGN_MIDDLE);
            cell.setUseAscender(true);
            cell.setUseDescender(true);
            table.addCell(cell);
            document.add(table);
        }catch (Exception e){
            e.printStackTrace();
            log.error("PDF異常"+e.getMessage());
        }
    }