使用iText生成带底图的PDF

package com.wzh.itext;

import com.itextpdf.text.Chunk;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * @date 2015-3-17 12:48:24
 * @author y
 * @desc 
 */
public class ItextUtil {
    
    /**
     * 生成带底图的PDF字节流
     * @param swdjz
     * @return 
     */
    public static byte[] createPdfBytes(Swdjz swdjz){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte []content = null;
        
        
        Document doc = new Document(PageSize.A4.rotate(), 50, 50, 50, 50); //创建文档 ,A4纸，横屏 
        
         try {
            PdfWriter pw = PdfWriter.getInstance(doc, baos);
            doc.open();
            
            //解决中文不显示问题
            BaseFont bfChinese = BaseFont.createFont("STSong-Light","UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
            //定义字体
            Font fontChinaTitle14 = new Font(bfChinese, 14, Font.BOLD);
            Font fontChina16 = new Font(bfChinese, 16);
            Font fontChina14 = new Font(bfChinese, 14);
            
            //加载电子税务登记证背景图片
            Image imgBg = Image.getInstance(swdjz.getBgPath());
            imgBg.setAbsolutePosition(0, 0); //设置图片位置
            imgBg.scaleAbsolute(842, 595);//设置图片大小
            doc.add(imgBg);
            
            // 空行
            Paragraph blank = new Paragraph(" ");
            doc.add(blank);
            doc.add(blank);
            doc.add(blank);
            doc.add(blank);
            doc.add(blank);
            
            /*右上角信息*/
            //档案号
            Chunk c01 = new Chunk(swdjz.getDanh(), fontChina16);
            Paragraph snoParagraph01 = new Paragraph();
            snoParagraph01.add(c01);
            snoParagraph01.setAlignment(Element.ALIGN_RIGHT);
            snoParagraph01.setIndentationRight(30);
            snoParagraph01.setSpacingBefore(10);
            doc.add(snoParagraph01);
            //纳税人识别号
            Chunk c02 = new Chunk(swdjz.getNsrsbh(), fontChina16);
            Paragraph snoParagraph02 = new Paragraph();
            snoParagraph02.add(c02);
            snoParagraph02.setAlignment(Element.ALIGN_RIGHT);
            snoParagraph02.setIndentationRight(28);
            doc.add(snoParagraph02);
            
            doc.add(blank);
            doc.add(blank);
            
            /*正文*/
            //纳税人名称
            Chunk c03 = new Chunk(swdjz.getNsrmc(), fontChina16);
            Paragraph snoParagraph03 = new Paragraph();
            snoParagraph03.add(c03);
            snoParagraph03.setIndentationLeft(220);
            doc.add(snoParagraph03);
            
            doc.add(blank);
            
            //法定代表人
            Chunk c04 = new Chunk(swdjz.getFddbr(), fontChina16);
            Paragraph snoParagraph04 = new Paragraph();
            snoParagraph04.add(c04);
            snoParagraph04.setIndentationLeft(220);
            doc.add(snoParagraph04);
            
            doc.add(blank);
            
            //地址
            Chunk c05 = new Chunk(swdjz.getDz(), fontChina16);
            Paragraph snoParagraph05 = new Paragraph();
            snoParagraph05.add(c05);
            snoParagraph05.setIndentationLeft(220);
            snoParagraph05.setSpacingBefore(3);
            doc.add(snoParagraph05);
            
            doc.add(blank);
            
            //登记注册类型
            Chunk c06 = new Chunk(swdjz.getDjzclx(), fontChina16);
            Paragraph snoParagraph06 = new Paragraph();
            snoParagraph06.add(c06);
            snoParagraph06.setIndentationLeft(220);
            snoParagraph06.setSpacingBefore(4);
            doc.add(snoParagraph06);
            
            doc.add(blank);
            
            //经营范围
            Chunk c07 = new Chunk(swdjz.getJyfw(), fontChina14);
            Paragraph snoParagraph07 = new Paragraph();
            snoParagraph07.add(c07);
            snoParagraph07.setIndentationLeft(220);
            doc.add(snoParagraph07);
            
            doc.add(blank);
            
            //批准设立机关
            Chunk c08 = new Chunk(swdjz.getPzsljg(), fontChina16);
            Paragraph snoParagraph08 = new Paragraph();
            snoParagraph08.add(c08);
            if(swdjz.getJyfw().length()>37){
                snoParagraph08.setSpacingBefore(-10);
            }else{
                snoParagraph08.setSpacingBefore(4);
            }
            snoParagraph08.setIndentationLeft(220);
            doc.add(snoParagraph08);
            
            doc.add(blank);
            
            //扣缴义务
            Chunk c09 = new Chunk(swdjz.getKjyw(), fontChina16);
            Paragraph snoParagraph09 = new Paragraph();
            snoParagraph09.add(c09);
            if(swdjz.getJyfw().length()<38){
                snoParagraph09.setSpacingBefore(4);
            }
            snoParagraph09.setIndentationLeft(220);
            doc.add(snoParagraph09);
            
            doc.add(blank);
            doc.add(blank);
            doc.add(blank);
            
            /*右下角*/
            //发证日期
            Chunk cYear = new Chunk("一三     ", fontChina16);
            Chunk cMonth = new Chunk("   八   ", fontChina16);
            Chunk cDay = new Chunk("   十二   ", fontChina16);
            
            Paragraph snoParagraph10 = new Paragraph();
            snoParagraph10.add(cYear);
            snoParagraph10.add(cMonth);
            snoParagraph10.add(cDay);
            snoParagraph10.setSpacingBefore(4);
            snoParagraph10.setIndentationRight(45);
            snoParagraph10.setAlignment(Element.ALIGN_RIGHT);
            doc.add(snoParagraph10);
            
            
            doc.close();
            
            content = baos.toByteArray();
            
        } catch (FileNotFoundException ex) {
            Logger.getLogger(ItextUtil.class.getName()).log(Level.SEVERE, null, ex);
        } catch (DocumentException ex) {
            Logger.getLogger(ItextUtil.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(ItextUtil.class.getName()).log(Level.SEVERE, null, ex);
        }finally{
            try {
                baos.close();
            } catch (IOException ex) {
                Logger.getLogger(ItextUtil.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        
        return content;
    }
    
}

Servlet 中：

 response.setContentType("application/pdf");
        
        ServletOutputStream sos = response.getOutputStream();
        
        response.setHeader("Content-Disposition", "attachment;filename="
                        + new String(swdjz.getNsrmc().getBytes(), "iso-8859-1"));

        
        byte [] content = ItextUtil.createPdfBytes(swdjz);
        
        BufferedOutputStream bos = new BufferedOutputStream(sos);
        bos.write(content);
        
        bos.close();