SpringMVC文件上传和下载

准备工作

导入依赖

<!--文件上传-->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>

配置springmvc.xml

<!---配置文件上传解析器，将上传的文件封装为MultipartFile-->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!--请求的编码格式，必须和jsp的pageEncoding属性一致，以便正确读取表单的内容，默认为ISO-8859-1-->
        <property name="defaultEncoding" value="utf-8"/>
        <!--上传文件大小上限，单位为字节(10485760=10M)-->
        <property name="maxUploadSize" value="1048560"/>
        <property name="maxInMemorySize" value="40960"/>
    </bean>

文件上传

编写前端页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>文件上传</title>
</head>
<body>
<form th:action="@{/testUp}" method="post" enctype="multipart/form-data">
    头像:<input type="file" name="photo"><br/>
    <input type="submit" value="上传">
</form>
</body>
</html>

编写controller层

@Controller
public class FileUpAndDownload {

    @RequestMapping("/testUp")
    public String testUp(MultipartFile photo, HttpSession session) throws IOException {
       //获取文件名
        String filename = photo.getOriginalFilename();
        //获取后缀名
        String suffixName = filename.substring(filename.lastIndexOf("."));
        String uuid = UUID.randomUUID().toString().replace("-","");
        filename = filename + uuid;

        ServletContext servletContext = session.getServletContext();
        //上传路径保存设置
        String path = servletContext.getRealPath("photo");
        //如果路径不存在，创建一个
        File file = new File(path);
        if (!file.exists()) {
            file.mkdir();
        }
        String finalPath = path + File.separator + filename;
        photo.transferTo(new File(finalPath));

        return "success";
    }
}

文件下载

编写前端页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>文件下载</title>
</head>
<body>
<a th:href="@{/testDown}">文件下载</a>
</body>
</html>

编写controller层

@Controller
public class FileUpAndDownload {

    @RequestMapping("/testDown")
    public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException {
        //获取ServletContext对象
        ServletContext servletContext = session.getServletContext();
        //获取服务器中文件的真实路径
        String realPath = servletContext.getRealPath("/static/img/1.jpg");
        System.out.println("realPath=" + realPath);
        //创建输入流
        InputStream is = new FileInputStream(realPath);
        //创建字节数组
        byte[] bytes = new byte[is.available()];
        //将流读到字节数组中
        is.read(bytes);
        //创建HttpHeaders对象设置响应头信息
        MultiValueMap<String, String> headers = new HttpHeaders();
        //设置要下载方式以及下载文件的名字
        headers.add("Content-Disposition", "attachment;filename=1.jpg");
        //设置响应状态码
        HttpStatus statusCode = HttpStatus.OK;
        //创建ResponseEntity对象
        ResponseEntity<byte[]> responseEntity = new ResponseEntity<>(bytes, headers, statusCode);
        //关闭输入流
        is.close();
        return responseEntity;
    }
}
posted @ 2021-09-19 21:04  SEVEN_CCODE  阅读(53)  评论(0)    收藏  举报