SpringBoot文件访问映射的两种实现方式

╰+哭是因爲堅強的太久メ 2023-10-07 17:24 8阅读 0赞

### SpringBoot文件访问映射的两种实现方式 ###

> 业务需求：通过SpringBoot访问服务器（磁盘内）的所有文件，用于正常项目中上传图片（文件）的访问。

**图片路径：E://images/upload/123.jpg，现在通过两种方式实现对图片的访问**

### 方式一（推荐）： ###

增加配置类实现WebMvcConfigurer接口，然后在addResourceHandlers方法中设置文件夹与访问路径之间的映射关系。  
参考代码：

@Configuration
    public class FileConfig implements WebMvcConfigurer {
        
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
        
            registry.addResourceHandler("/upload/**").addResourceLocations("file:" + "E://images/upload/");
        }
    }

访问示例：  
**http://localhost:8080/upload/123.jpg**

### 方式二： ###

专门新增一个接口作为图片（文件）访问的入口，接口中要进行编码转换，而且可以设置文件**强制下载不打开**  
参考代码：

@RestController
    @RequestMapping("/file")
    public class FileController {
        
        private static final String FILE_PATH = "E://images/upload/";
    
        @GetMapping(value = "/static/**")
        public void view(HttpServletRequest request, HttpServletResponse response) {
        
            String imgPath = extractPathFromPattern(request);
            if(StringUtil.isEmpty(imgPath) || imgPath=="null"){
        
                return;
            }
            InputStream inputStream = null;
            OutputStream outputStream = null;
            try {
        
                imgPath = imgPath.replace("..", "");
                if (imgPath.endsWith(",")) {
        
                    imgPath = imgPath.substring(0, imgPath.length() - 1);
                }
                String fileUrl = FILE_PATH + imgPath;
                File file = new File(fileUrl);
                if(!file.exists()){
        
                    response.setStatus(404);
                    throw new RuntimeException("文件不存在..");
                }
                response.setContentType("application/force-download");// 设置强制下载不打开
                response.addHeader("Content-Disposition", "attachment;fileName=" + new String(file.getName().getBytes("UTF-8"),"iso-8859-1"));
                inputStream = new BufferedInputStream(new FileInputStream(fileUrl));
                outputStream = response.getOutputStream();
                byte[] buf = new byte[1024];
                int len;
                while ((len = inputStream.read(buf)) > 0) {
        
                    outputStream.write(buf, 0, len);
                }
                response.flushBuffer();
            } catch (IOException e) {
        
                response.setStatus(404);
                e.printStackTrace();
            } finally {
        
                if (inputStream != null) {
        
                    try {
        
                        inputStream.close();
                    } catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
                if (outputStream != null) {
        
                    try {
        
                        outputStream.close();
                    } catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
            }
        }
    
        /**
         *  ISO-8859-1 => UTF-8 进行编码转换
         */
        private static String extractPathFromPattern(final HttpServletRequest request) {
        
            String path = (String) request.getAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
            String bestMatchPattern = (String) request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
            return new AntPathMatcher().extractPathWithinPattern(bestMatchPattern, path);
        }
    }

访问示例：  
**http://localhost:8080/file/static/123.jpg**