SpringMVC studies four (file upload / interceptor)

1. File Upload

1.1 preparatory work, we need two jar package ( the Fileupload )

jar package download path:

[Download https://github.com/suyirulan/putao/tree/master/fileupload_jar ]

Jsp page upload 1.2 below, note sheet form tag attribute file uploading method = "post" enctype = " multipart / form-data" is required , and the file name = "" is also necessary

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>上传文件</title>
 8 </head>
<9 body>
10     <form action="addStudent" method="post" enctype="multipart/form-data">
11         姓名：<input type="text" name="name"/><br>
12         年龄：<input type="text" name="age"/><br>
13         头像：<input type="file" name="headphoto"/><br>
14         <input type="submit" value="上传"/>
15     </form>
16 </body>
17 </html>

1.3 Upload configuration file parser springmvc

Wherein value = "99999999" to limit the maximum number of bytes uploaded file (bytes: 1M = 1024K = 1024 * 1024 = 1048576 bytes )

1 <!-- 文件上传解析器 -->
2 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
3     <property name="maxUploadSize" value="99999999"></property>
4 </bean>

Controller Code 1.4 Upload file

. 1  @Controller
 2  public  class StudentController {
 . 3      
. 4      @RequestMapping ( "addStudent" )
 . 5      public String addStudent (Student STU, the HttpServletRequest Request, a MultipartFile headphoto, the Model Model) {
 . 6          // 1. Get real path to save a file to upload 
. 7          String path = . request.getServletContext () getRealPath ( "/ headphoto" );
 8          // 2. create a file object 
9          file file = new new file (path);
 10          // If the file does not create 
11          IF (! File.Exists ( )) {
 12             file.mkdirs();
13         }
14         //3.获取文件名
15         String filename=System.currentTimeMillis()+headphoto.getOriginalFilename();
16         
17         stu.setPhoto("headphoto/"+filename);
18         
19         File targetFile =new File(path+"/"+filename);
20         
21         try {
22             FileUtils.writeByteArrayToFile(targetFile, headphoto.getBytes());
23         } catch (IOException e) {
24             // TODO Auto-generated catch block
25             e.printStackTrace();
26         }
27         
28         model.addAttribute("stu",stu);
29         
30         return "index";
31     }
32 }

carry out testing

Upload successful

2. interceptor (control layer address are intercepted, filter: page address can intercept requests)

2.1 create a class that implements the interface Handlerinterceptor

2.2 Method rewriting interface

 1 public class MyInterceptor implements HandlerInterceptor{
 2 
 3     @Override
 4     public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
 5             throws Exception {
 6         // TODO Auto-generated method stub
 7         
 8     }
 9 
10     @Override
11     public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
12             throws Exception {
13         // TODO Auto-generated method stub
14         
15     }
16 
17     @Override
18     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object arg2) throws Exception {
19         Object name = request.getSession().getAttribute("name");
20         if(name!=null) {
21             return true;
22         }else {
23             System.out.println("拦截器");
24             return false;
25         }
26     }
27
28 }

2.3把创建的类配置到SpringMVC文件中,其中<mvc:mapping path=" "/>为拦截的，<mvc:exclude-mapping path=" "/>为放行的

1 <!-- 拦截器 -->
2     <mvc:interceptors>
3         <mvc:interceptor>
4             <mvc:mapping path="/user/**"/>
5             <mvc:exclude-mapping path="/user/login1"/>
6             <mvc:exclude-mapping path="/user/denglu"/>
7             <bean class="com.zhiyou100.zhl.interceptor.MyInterceptor"></bean>
8         </mvc:interceptor>
9     </mvc:interceptors>

Fileupload

SpringMVC studies four (file upload / interceptor)

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