Introduction to SpringMVC file upload method (code)-JS Tutorial-php.cn

This article brings you an introduction to the SpringMVC file upload method (code). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

SpringMVC provides direct support for file upload, which is implemented using the plug-and-play MultipartResolver. SpringMVC uses Apache Commons FileUpload technology to implement a MultipartResolver implementation class: CommonsMultipartResolver. Therefore, SpringMVC's file upload also needs to rely on the Apache Commons FileUpload component.

1. Add pom dependency

    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.3</version>
    </dependency>
    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.2</version>
    </dependency>

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2. Configuration file upload bean

Add one in the spring mvc configuration file File upload bean.

    <!-- SpringMVC上传文件时，需要配置MultipartResolver处理器 -->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="UTF-8" />
    </bean>

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3. File upload

File upload is the most common function in project development. In order to upload files, the form method must be set to POST and the enctype must be set to multipart/form-data. Only in this case will the browser send the file selected by the user to the server as binary data.

Upload file interface: upload_form.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>文件上传</title>
</head>
<body>

<!-- 上传单个对象 注意表单的method属性设为post,enctype属性设为multipart/form-data -->
<form method="POST" action="/SpringMVCDemo1/upload" enctype="multipart/form-data">
    <input type="file" name="file" /><br/><br/>
    <input type="submit" value="上传" />
</form>

<!-- 上传多个对象 注意表单的method属性设为post,enctype属性设为multipart/form-data -->
<form method="POST" action="/SpringMVCDemo1/uploadMultiFiles" enctype="multipart/form-data">
    <p>文件1：<input type="file" name="file" /></p>
    <p>文件2：<input type="file" name="file" /></p>
    <p>文件3：<input type="file" name="file" /></p>
    <!-- 同时传递其他业务字段 -->
    <p>用户名：<input type="text" name="userName" /></p>
    <p>密码：<input type="password" name="password" /></p>
    <p><input type="submit" value="上传" /></p>
</form>
</body>
</html>

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Upload result return interface: upload_result.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <h2>上传结果为：${message}</h2>
</body>
</html>

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Note: Create a folder to store files in advance, for example, my path is: "D:staticResourcesTestimgupload".

FileController.java

@Controller
@RequestMapping("/SpringMVCDemo1")
public class FileController {
    /**
     * 跳转到上传页面
     * @GetMapping 是一个组合注解，是@RequestMapping(method = RequestMethod.GET)的缩写。
     */
    @GetMapping("/gotoUploadForm")
    public String index() {
        return "/upload_form.jsp";
    }

    /**
     * 上传单个文件
     * 通过MultipartFile读取文件信息，如果文件为空跳转到结果页并给出提示；
     * 如果不为空读取文件流并写入到指定目录，最后将结果展示到页面
     * @param multipartFile
     * @PostMapping 是一个组合注解，是@RequestMapping(method = RequestMethod.POST)的缩写。
     */
    @PostMapping("/upload")
    public String uploadSingleFile(@RequestParam("file") MultipartFile multipartFile, HttpServletRequest request){
        if (multipartFile.isEmpty()){
            request.setAttribute("message",  "Please select a file to upload '");
            return "/upload_result.jsp";
        }

        try {
            String contentType = multipartFile.getContentType();
            String originalFilename = multipartFile.getOriginalFilename();
            byte[] bytes = multipartFile.getBytes();
            System.out.println("上传文件名为-->" + originalFilename);
            System.out.println("上传文件类型为-->" + contentType);
            System.out.println("上传文件大小为-->"+bytes.length);

            //filePath为存储路径
            String filePath = "d:/staticResourcesTest";
            System.out.println("filePath-->" + filePath);
            //存储在staticResourcesTest下的imgupload文件夹下
            File parentPath = new File(filePath, "imgupload");
            System.out.println("上传目的地为-->"+parentPath.getAbsolutePath());
            try {
                File destFile = new File(parentPath,originalFilename);//上传目的地
                FileUtils.writeByteArrayToFile(destFile,multipartFile.getBytes());
            } catch (Exception e) {
                e.printStackTrace();
            }
            request.setAttribute("message",  "You successfully uploaded '" + multipartFile.getOriginalFilename() + "'");

        } catch (IOException e) {
            e.printStackTrace();
        }
        return "/upload_result.jsp";
    }

    /**
     * 上传多个文件，同时接受业务数据
     * @param origFiles
     * @param request
     * @param user
     * @return
     */
    @PostMapping("/uploadMultiFiles")
    public String uploadMultiFiles(@RequestParam("file") List<MultipartFile> origFiles, HttpServletRequest request, User user) {
        //User为实体类
        System.out.println("User=="+user);
        if (origFiles.isEmpty()) {
            request.setAttribute("message",  "Please select a file to upload '");
            return "/upload_result.jsp";
        }

        try {
            for (MultipartFile origFile : origFiles) {
                String contentType = origFile.getContentType();
                String fileName = origFile.getOriginalFilename();
                byte[] bytes = origFile.getBytes();
                System.out.println("上传文件名为-->" + fileName);
                System.out.println("上传文件类型为-->" + contentType);
                System.out.println("上传文件大小为-->"+bytes.length);

                String filePath = "d:/staticResourcesTest";
                System.out.println("上传目的地为-->"+filePath);
                try {
                    //上传目的地（staticResourcesTest文件夹下）
                    File destFile = new File(filePath,fileName);
                    FileUtils.writeByteArrayToFile(destFile,origFile.getBytes());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            request.setAttribute("message",  "You successfully uploaded '");
        } catch (IOException e) {
            e.printStackTrace();
        }

        return "/upload_result.jsp";
    }
}

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