本次做订餐系统中，需要用到在Java生成二维码，并在jsp页面打印并输出，其中在action中生成二维码.
关键代码如下
1 public void reWeiMa() throws Exception{
2 //设置页面不缓存
3 HttpServletResponse response = ServletActionContext.getResponse();
4 HttpServletRequest quest = ServletActionContext.getRequest();
5 Domain domain=domainService.getIp();
6 if(domain!=null){
7 String IP =domain.getIp();
8 response.setHeader("Pragma","No-cache");
9 response.setHeader("Cache-Control","no-cache");
10 response.setDateHeader("Expires", 0);
11
12 BufferedImage image=null;
13 ServletOutputStream stream = null;
14 //二维码的图片格式
15 String format = "gif";
16 String path= quest.getScheme() + "://"+IP+ ":" + quest.getServerPort()+ quest.getContextPath() + "/";
17 String content=path+"OrderDetail_getMenuMaterial?menuId="+menuId;
18 int width2 = 200;
19 int height2 = 200;
20
21 Hashtable hints = new Hashtable();
22 //内容所使用编码
23 hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
24
25 try{
26 BitMatrix bitMatrix = new MultiFormatWriter().encode(content,BarcodeFormat.QR_CODE, width2, height2, hints);
27 int width = bitMatrix.getWidth();
28 int height = bitMatrix.getHeight();
29 image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
30 for (int x = 0; x < width; x++) {
31 for (int y = 0; y < height; y++) {
32 image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF); //二维码图片为黑白两色
33 }
34 }
35 //ImageIO.write(image,"gif",response.getOutputStream());
36 }catch (Exception e) {
37 // TODO: handle exception
38 }
39 //只有用这种解码方式才不出现乱码
40 String s="attachment;filename="+new String("No"+menuId+".gif");
41 response.addHeader("Content-Disposition",s);
42 OutputStream os=new BufferedOutputStream(response.getOutputStream());
43 response.setContentType("image/gif");
44 ImageIO.write(image,format,os);
45 os.flush();
46 os.close();
47 }else{
48 String messige="未添加域名,暂无法打印二维码";
49 request.put("messige", messige);
50 }
51 }
jsp页面代调用生成二维码方法后，返回到打印二维码jsp中，代码如下
1 <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
2 pageEncoding="ISO-8859-1"%>
3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
4 <html>
5 <head>
6 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
7 <title>Insert title here</title>
8 </head>
9 <body>
10 <div style="text-align:center;">
11 <img src="${rootPath}/OrderDetail_reWeiMa?menuId=${menuId}">
12 </div>
13
14 <script type="text/javascript">
15 window.onload = function(){
16 window.print()
17 window.close()//打印后返回到原界面
18 }
19
20 </script>
21 </body>
22 </html>
在这里的思路是在action生成的的二维码放入src标签中，直接打印整个jsp，在这个过程中，遇到了一个问题，原本调用Java内部print方法来打印二维码，但在这个过程中遇到系统无法找到指定路径，（二维码生成在服务器上，浏览器调用服务器内容），最后使用简便方法，直接打印整个jsp页面.
时间： 2024-12-21 09:06:00