began to contact SPRINGMVC, a little anticipation, a little excited. Single little thing about today almost made me fall apart. In this record, not to record what technical points, is purely to warn themselves, and then careful not too!
A small example was made:
Set up the Springmvc shelf, guide the relevant package (when it is necessary to make a file upload Commons-fileupload.jar this must be).
① Configure the Web. xml file:
<?XML version= "1.0" encoding= "UTF-8"?><Web-appXmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"xmlns= "Http://xmlns.jcp.org/xml/ns/javaee"xsi:schemalocation= "Http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"ID= "webapp_id"version= "3.1"> <!--Configuring the Springmvc dispatcherservlet - <!--the front controller of this Spring WEB application, responsible-handling all application requests - <servlet> <Servlet-name>Springdispatcherservlet</Servlet-name> <Servlet-class>Org.springframework.web.servlet.DispatcherServlet</Servlet-class> <Init-param> <Param-name>Contextconfiglocation</Param-name> <Param-value>Classpath:springmvc.xml</Param-value> </Init-param> <Load-on-startup>1</Load-on-startup> </servlet> <!--Map All requests to the Dispatcherservlet for handling - <servlet-mapping> <Servlet-name>Springdispatcherservlet</Servlet-name> <Url-pattern>/</Url-pattern> </servlet-mapping> <!--configuration hiddenhttpmethodfilter: Convert post to delete, put request - <Filter> <Filter-name>Hiddenhttpmethodfilter</Filter-name> <Filter-class>Org.springframework.web.filter.HiddenHttpMethodFilter</Filter-class> </Filter> <filter-mapping> <Filter-name>Hiddenhttpmethodfilter</Filter-name> <Url-pattern>/*</Url-pattern> </filter-mapping></Web-app>
② Configure the Springmvc.xml file:
<?XML version= "1.0" encoding= "UTF-8"?><Beansxmlns= "Http://www.springframework.org/schema/beans"Xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"Xmlns:context= "Http://www.springframework.org/schema/context"Xmlns:mvc= "Http://www.springframework.org/schema/mvc"xsi:schemalocation= "Http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd Http://www.springframework.org/schema/context http://www.springframework.org/schema/context/ Spring-context-4.2.xsd Http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/ Spring-mvc-4.2.xsd "> <!--Configuring an automatic Scan package - <Context:component-scanBase-package= "Com.springmvc"></Context:component-scan> <!--configuration is Diagram parser - <Beanclass= "Org.springframework.web.servlet.view.InternalResourceViewResolver"> < Propertyname= "prefix"value= "/web-inf/views/"></ Property> < Propertyname= "suffix"value= ". jsp"></ Property> </Bean> <!--configuration multipartresover: For file uploads - <BeanID= "Multipartresover"class= "Org.springframework.web.multipart.commons.CommonsMultipartResolver"> < Propertyname= "Defaultencoding"value= "UTF-8"></ Property> < Propertyname= "Maxuploadsize"value= "1024000"></ Property> </Bean></Beans>
③ then start writing JSP files index.jsp:
<%@ Page Language="Java"ContentType="text/html; Charset=utf-8"pageencoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd ">
<HTML> <Head>
<Metahttp-equiv= "Content-type"content= "text/html; charset=utf-8">
<title>Insert Title here</title> </Head>
<Body> <formID= "form"Action= "Testfileupload"Method= "Post"enctype= "Multipart/form-data">
File:<inputtype= "File"name= "File" />
Desc:<inputtype= "text"name= "desc" />
<inputtype= "Submit"value= "Submit" />
</form>
</Body>
</HTML>
④ Start writing Java code:
Package Com.springmvc.test;import Java.io.ioexception;import Org.springframework.stereotype.controller;import Org.springframework.web.bind.annotation.requestmapping;import Org.springframework.web.bind.annotation.requestparam;import org.springframework.web.multipart.multipartfile;@ Controllerpublic class Springmvctest {@RequestMapping ("/testfileupload") public String testfileupload (@RequestParam ( Value= "desc", Required=false) String desc, @RequestParam (value= "file", Required=false) Multipartfile file) throws IOEXCEPTION{SYSTEM.OUT.PRINTLN ("desc:" + desc); System.out.println ("OriginalFilename:" + file.getoriginalfilename ()); System.out.println ("InputStream:" +file.getinputstream ()); return "Success";}}The relevant files are well, there is a success.jsp to write, just write a page on the line.
Start running, a run on the wrong nullpoint, check the cause "System.out.println (" OriginalFilename: "+ file.getoriginalfilename ());" Null pointer, that is, file is null, how can it?
Related configuration and packages have Ah, step-by-step look down to find the configuration Springmvc.xml file ID is wrong, a "L", the ID should be "configuration Multipartresolver", Tragedy ah ... So write something must be careful ah, can copy the copy it as far as possible, otherwise a little notice on the sad urge ...
Springmvc_ File Upload Example
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
