【SpringMvc】SpringMvc文件上传与下载

超、凢脫俗 2022-11-21 11:44 241阅读 0赞

### 文章目录 ###

*  文件上传
 *   *  1 前端代码
     *  2 路径配置
     *  3 Controller
     *  4 外部访问配置\`ResourceHandler\`
 *  文件下载
 *  完整代码
 *   *  1 WebConfig
     *  2 UpLoadAndDownLoadController
     *  3 Maven依赖

# 文件上传 #

## 1 前端代码 ##

## 2 路径配置 ##

server:
      port: 8080
    file-path: ./appData/

## 3 Controller ##

@Value("${file-path}")
        private String path;
    
        @Autowired
        HttpServletRequest request;
    
        /**
         * 文件上传
         *
         * @param multipartFile
         * @return
         */
        @PostMapping("/upload")
        private String upLoad(MultipartFile multipartFile) {
        
            if (multipartFile != null) {
        
                String originalFilename = multipartFile.getOriginalFilename();
                File filePath = new File(request.getServletContext().getRealPath(path) + File.separator + originalFilename);
                if (!filePath.getParentFile().exists()) {
        
                    filePath.getParentFile().mkdirs();
                }
                try {
        
                    multipartFile.transferTo(filePath);
                    return "upload success";
                } catch (IOException e) {
        
                    e.printStackTrace();
                }
            }
            return "upload failed";
        }

## 4 外部访问配置`ResourceHandler` ##

/**
     * @author: Curiosity
     * @Date: 2020/11/1 14:24
     * @Description:
     */
    @Configuration
    /**
     *  lombok为所有final 变量生成构造方法与Spring配合进行注入
     */
    @RequiredArgsConstructor
    public class WebConfig implements WebMvcConfigurer {
        
        /**
         * final 构造器注入
         */
        final ConfigurableEnvironment configurableEnvironment;
        final ServletContext servletContext;
        @Value("${file-path}")
        private String filePath;
    
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
        
            // 获取真实路径
            String realPath = servletContext.getRealPath(filePath);
            // 添加句柄 http://127.0.0.1:8080/file/git.md
            registry.addResourceHandler("/file/**")
                    // 添加文件真实路径
                    .addResourceLocations("file:" + realPath)
                    .setCacheControl(CacheControl.maxAge(1, TimeUnit.DAYS));
        }
    }

# 文件下载 #

1 Controller

@GetMapping("/down/{fileName}")
        private ResponseEntity<Resource> downLoad(@PathVariable String fileName) {
        
            File file = new File(request.getServletContext().getRealPath(path) + File.separator + fileName);
            if (!file.exists()) {
        
                return new ResponseEntity(HttpStatus.NOT_FOUND);
            }
    
            try {
        
                Path path = Paths.get(file.getAbsolutePath());
                HttpHeaders headers = new HttpHeaders();
                ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));
                headers.setContentDispositionFormData("attachment", new String(fileName.getBytes("UTF-8"), "ISO-8859-1"));
                return ResponseEntity.ok()
                        .contentLength(file.length())
                        .headers(headers)
                        .contentType(MediaType.APPLICATION_OCTET_STREAM)
                        .body(resource);
            } catch (UnsupportedEncodingException e) {
        
                e.printStackTrace();
            } catch (Exception e) {
        
                e.printStackTrace();
            }
            return new ResponseEntity(HttpStatus.BAD_REQUEST);
    
        }

# 完整代码 #

## 1 WebConfig ##

@Configuration
    /**
     *  lombok为所有final 变量生成构造方法与Spring配合进行注入
     */
    @RequiredArgsConstructor
    public class WebConfig implements WebMvcConfigurer {
        
        /**
         * final 构造器注入
         */
        final ConfigurableEnvironment configurableEnvironment;
        final ServletContext servletContext;
        @Value("${file-path}")
        private String filePath;
    
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
        
            // 获取真实路径
            String realPath = servletContext.getRealPath(filePath);
            // 添加句柄 http://127.0.0.1:8080/file/git.md
            registry.addResourceHandler("/file/**")
                    // 添加文件真实路径
                    .addResourceLocations("file:" + realPath)
                    .setCacheControl(CacheControl.maxAge(1, TimeUnit.DAYS));
        }
    }

## 2 UpLoadAndDownLoadController ##

/**
     * @author: Curiosity
     * @Date: 2020/11/1 09:52
     * @Description:
     */
    @RestController
    public class UpLoadAndDownLoadController {
        
    
        @Value("${file-path}")
        private String path;
    
        @Autowired
        HttpServletRequest request;
    
        /**
         * 文件上传
         *
         * @param multipartFile
         * @return
         */
        @PostMapping("/upload")
        private String upLoad(MultipartFile multipartFile) {
        
            if (multipartFile != null) {
        
                String originalFilename = multipartFile.getOriginalFilename();
                File filePath = new File(request.getServletContext().getRealPath(path) + File.separator + originalFilename);
                if (!filePath.getParentFile().exists()) {
        
                    filePath.getParentFile().mkdirs();
                }
                try {
        
                    multipartFile.transferTo(filePath);
                    return "upload success";
                } catch (IOException e) {
        
                    e.printStackTrace();
                }
            }
            return "upload failed";
        }
    
        @GetMapping("/down/{fileName}")
        private ResponseEntity<Resource> downLoad(@PathVariable String fileName) {
        
            File file = new File(request.getServletContext().getRealPath(path) + File.separator + fileName);
            if (!file.exists()) {
        
                return new ResponseEntity(HttpStatus.NOT_FOUND);
            }
    
            try {
        
                Path path = Paths.get(file.getAbsolutePath());
                HttpHeaders headers = new HttpHeaders();
                ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));
                headers.setContentDispositionFormData("attachment", new String(fileName.getBytes("UTF-8"), "ISO-8859-1"));
                return ResponseEntity.ok()
                        .contentLength(file.length())
                        .headers(headers)
                        .contentType(MediaType.APPLICATION_OCTET_STREAM)
                        .body(resource);
            } catch (UnsupportedEncodingException e) {
        
                e.printStackTrace();
            } catch (Exception e) {
        
                e.printStackTrace();
            }
            return new ResponseEntity(HttpStatus.BAD_REQUEST);
    
        }
    }

## 3 Maven依赖 ##

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>