SpringMVC based file uploads

#### 1. Create a project

to create a `Maven Project`,` Group Id` as `cn.tedu.spring`,` Artifact Id` select `war` as` SRPINGMVC-03-UPLOAD`, ` Packaging`.

In addition to adding the necessary SpringMVC dependence, also you need to add `commons-fileupload` dependency:

    <dependency>
        <groupId>commons-fileupload</groupId>
        <artifactId>commons-fileupload</artifactId>
        <version>1.4</version>
    </dependency>

 

#### 2. Static pages

created `index.html` in` webapp` project, the page Requirements:

1. The form `<form>` `method` the property must be` post`, because the uploaded file relative to the average amount of data request parameter, the data is very large, URL does not fit, Further, the value of `genus enctype` values must be` multipart / form-data`:

  <form action="" method="post" enctype="multipart/form-data">

 

2. The form must have controls to navigate the file:

    <input type="file" />

The complete code for example:

    <form action="" method="post" enctype="multipart/form-data">
        <P> Please select the file you want to upload: </ p>
        <p><input type="file" /></p>
        <p><input type="submit" value="上传" /></p>
    </form>

3. receiving an upload request ####

first checks `spring-mvc.xml` regarding component scans the configuration of the root package, and then create` cn.tedu.spring.UploadController` controller class, adding annotation `@ Controller` , then add in the method of processing request controller class:

    @RequestMapping("upload.do")
    public String upload() {
        return null;
    }

In the method of processing the request, add `MultipartFile` type parameter, which is uploaded by the client object file package obtained, while processing a request, calling the parameter object` void transferTo (File) `method to save the file :

    @Controller
    public class UploadController {
    
        @RequestMapping("upload.do")
        public String upload(
            @RequestParam("file") MultipartFile file) throws IllegalStateException, IOException {
            // 执行保存
            File dest = new File("d:/1.jpg");
            file.transferTo ();
            return null;
        }
        
    }

 

`Action` property value of the static pages of the form must be` upload.do`, `name` property value of the control to browse files must be` file`.

Finally, before use `MultipartFile`, you must also configure` CommonsMultipartResolver` in `spring-mvc.xml` in:

    <! - need to use when configuring upload MultipartResolver ->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />