Spring MVC入门八：文件上传下载、拦截器、异常处理

文件 上传下载

导入文件上传所需的依赖

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.1</version>
</dependency>

springmvc配置文件

# 配置跳转到上传下载的页面
<mvc:view-controller path="/file" view-name="file"></mvc:view-controller>
# http://localhost:8080/上下文路径/ file

<!--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"></bean>

编写thymeleaf页面

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <Meta charset="UTF-8">
    <title>测试文件上传和下载</title>
</head>
<body>
<a th:href="@{/testDown}">下载1.jpg</a><br>
<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>

编写控制器

@Controller
public class FileUpAndDownController {

    @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);
        //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;
    }

    @RequestMapping("/testUp")
    public String testUp(multipartfile photo, HttpSession session) throws IOException {
        //获取上传的文件的文件名
        String fileName = photo.getoriginalFilename();
        //获取上传的文件的后缀名
        String suffixName = fileName.substring(fileName.lastIndexOf("."));
        //将UUID作为文件名
        String uuid = UUID.randomUUID().toString().replaceAll("-","");
        //将uuid和后缀名拼接后的结果作为最终的文件名
        fileName = uuid + suffixName;
        //通过ServletContext获取服务器中photo目录的路径
        ServletContext servletContext = session.getServletContext();
        String photoPath = servletContext.getRealPath("photo");
        File file = new File(photoPath);
        //判断photoPath所对应路径是否存在
        if(!file.exists()){
            //若不存在，则创建目录
            file.mkdir();
        }
        String finalPath = photoPath + File.separator + fileName;
        //上传文件
        photo.transferTo(new File(finalPath));
        return "success";
    }
}

Spring MVC入门八：文件上传下载、拦截器、异常处理

文件上传下载

拦截器

异常处理

相关推荐