Shulou(Shulou.com)06/02 Report--

In this issue, the editor will bring you about how to upload files in JavaWeb. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

Introduce dependency

Of course, before introducing dependencies, we need to create a Web Project managed by Maven. I won't say much about the creation method. If you are not familiar with it, you can refer to this article SpringMVC basic configuration (through annotated configuration, non-xml configuration). After the successful creation, you can add the following two dependencies to the SpringMVC framework:

Commons-fileupload commons-fileupload 1.3.2 commons-io commons-io 2.5

Two dependent libraries, one for file uploading and one for simplifying IO operations.

Create a file upload page

This is a simple jsp page. I create a views folder in the resources folder and an index.jsp file in the views folder, as follows:

File upload

This page is very simple, there is nothing to say, just note that action is upload.

Configure SpringMVC

This is a crucial step, but there is only one new Bean, so let's take a look at the class first:

@ Configuration@EnableWebMvc@ComponentScan ("org.sang") public class MVCConfig extends WebMvcConfigurerAdapter {@ Bean public InternalResourceViewResolver viewResolver () {InternalResourceViewResolver viewResolver = new InternalResourceViewResolver (); viewResolver.setPrefix ("/ WEB-INF/classes/views/"); viewResolver.setSuffix (".jsp"); viewResolver.setViewClass (JstlView.class); return viewResolver } @ Override public void addViewControllers (ViewControllerRegistry registry) {registry.addViewController ("/ index") .setViewName ("/ index");} @ Bean public MultipartResolver multipartResolver () {CommonsMultipartResolver resolver = new CommonsMultipartResolver (); resolver.setMaxUploadSize (1000000); return resolver;}}

This class has been mentioned several times in previous blogs, but there is only an additional multipartResolver method, which is used to provide a Bean of MultipartResolver. In this method, CommonsMultipartResolver is mainly configured according to business requirements. I'll take limiting the size of the upload file as an example.

Web configuration

This is also a clich é. The previous blogs have also said n many times, so I won't repeat it:

Public class WebInit implements WebApplicationInitializer {public void onStartup (ServletContext servletContext) throws ServletException {AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext (); context.register (MVCConfig.class); context.setServletContext (servletContext); ServletRegistration.Dynamic servlet = servletContext.addServlet ("dispatcher", new DispatcherServlet (context)); servlet.addMapping ("/"); servlet.setLoadOnStartup (1) }} write Controller@Controllerpublic class UploadController {@ ResponseBody @ RequestMapping (value = "/ upload", method = RequestMethod.POST,produces = "text/plain;charset=UTF-8") public String upload (MultipartFile file) {try {FileUtils.writeByteArrayToFile (new File ("/ home/sang/workspace/" + file.getOriginalFilename ()), file.getBytes ()); return "uploaded successfully" } catch (IOException e) {e.printStackTrace (); return "upload failed";}

Here, through the relevant methods provided in Common-IO, you can directly write the byte array of uploaded files into files.

Run the project at this time and open index.jsp in the browser, as follows:

The above is how to upload files in the JavaWeb shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.