SpringMVC: 文件上传

需要额外导入的jar(commons-io、4.0版本servlet)

        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.3</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
        </dependency>

springmvc配置 注入

    <!--文件上传的配置-->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="utf-8"/>
        <!--上传文件大小上限 单位为Byte-->
        <property name="maxInMemorySize" value="40960"/>
        <property name="maxUploadSize" value="10485760"/>
    </bean>

前端 form表单的解析格式设置

  <form action="/upload2" enctype="multipart/form-data" method="post">
    <input type="file" name="file"/>
    <input type="submit" value="提交">
  </form>

Controller层两种实现上传的方式

• 手动写缓冲区 实现上传文件

  // 上传 file 为前端传递的文件
    @RequestMapping("upload")
    public String upLoad(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {
        // 获取文件名
        String filename = file.getOriginalFilename();

        // 文件名为空 回到首页
        if (null == filename || "".equals(filename)){
            return "redirect:/index.jsp"; // 不走视图解析器
        }
        System.out.println("上传文件名：" + filename);

        // 上传路径保存 UUID
        String path = request.getServletContext().getRealPath("/upload");

        // 如果路径不存在 创建
        File realPath = new File(path);
        if (!realPath.exists()){
            realPath.mkdir();
        }

        System.out.println("上传文件保存地址：" + realPath);

        // 文件输入流 输出流
        InputStream inputStream = file.getInputStream();
        FileOutputStream outputStream = new FileOutputStream(new File(realPath, filename));

        // 读取写出
        int len = 0;
        byte[] buffer = new byte[1024];
        while ((len=inputStream.read(buffer))!=-1){
            outputStream.write(buffer,0,len);
            outputStream.flush();
        }
        outputStream.close();
        inputStream.close();
        return "redirect:/index.jsp";
    }

• springMVC自带的上传方法transferTo

 @RequestMapping("upload2")
    public void fileUpload2(@RequestParam("file") CommonsMultipartFile file,HttpServletRequest request) throws IOException {
        // 获取文件名
        String filename = file.getOriginalFilename();

        // 文件名为空
        if (null == filename || "".equals(filename)){
            return;
        }
        System.out.println("上传文件名：" + filename);

        // 文件保存路径
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if (!realPath.exists()){
            realPath.mkdir();
        }
        System.out.println("上传文件保存地址：" + realPath);

        file.transferTo(new File(realPath+"/"+filename));
        return;
    }