【微信开发】SpringMVC将url生成二维码图片直接展示在页面上

￡神魔★判官ぃ 2022-06-02 01:51 78阅读 0赞

利用google的开源包zxing生成二维码

第一步：maven项目的zxing依赖

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1 
     2 <dependency>
     3     <groupId>com.google.zxing</groupId>
     4     <artifactId>core</artifactId>
     5     <version>3.2.1</version>
     6 </dependency>
     7  <dependency>
     8           <groupId>com.google.zxing</groupId>
     9           <artifactId>javase</artifactId>
    10           <version>3.2.0</version>
    11  </dependency>

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第二步：jsp页面上写上调用生成二维码的controller图片标签

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1 <%@page import="sun.tools.tree.ThisExpression"%>
     2 <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
     3 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
     4 <html>
     5     <head>
     6         <title></title>
     7     </head>
     8     <body>
     9         <h1>微信扫码支付，请扫下面二维码</h1>
    10         <img class="q_code" src="<%=this.getServletContext().getContextPath() %>/services/wapwxdemo/getErWeiCode" />
    11     </body>
    12 </html>

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第三步：生成二维码的controller方法

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1 /**
     2      * 生成二维码，返回到页面上
     3      * @param response
     4      */
     5     @RequestMapping(value="/getErWeiCode",method={RequestMethod.POST,RequestMethod.GET} )
     6     public void getErWeiCode(HttpServletResponse response){
     7         String url="www.baidu.com";
     8         if(url!=null&&!"".equals(url)){
     9             ServletOutputStream stream=null;
    10             try {
    11                 int width=200;
    12                 int height=200;
    13                 stream=response.getOutputStream();
    14                 QRCodeWriter writer=new QRCodeWriter();
    15                 BitMatrix m=writer.encode(url, BarcodeFormat.QR_CODE, height,width);
    16                 MatrixToImageWriter.writeToStream(m, "png", stream);
    17             } catch (Exception e) {
    18                 // TODO: handle exception
    19                 e.printStackTrace();
    20             }finally{
    21                 if(stream!=null){
    22                     try {
    23                         stream.flush();
    24                         stream.close();
    25                     } catch (IOException e) {
    26                         // TODO Auto-generated catch block
    27                         e.printStackTrace();
    28                     }
    29                     
    30                 }
    31             }
    32         }
    33     }

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第四步：效果展示

如果用HTML  直接将<img>的src属性设置为url

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