实现文件预览的功能

electrmangnetic/src/main/java/com/electromagnetic/industry/software/manage/controller/EdFileInfoController.java

@@ -132,4 +132,10 @@ public class EdFileInfoController {
     public ElectromagneticResult<?> queryChildFolder(@RequestParam String parentId) {
         return edFileInfoService.queryChildFolder(parentId);
     }
+
+    @RequiredPermission(value = FilePermission.VIEW)
+    @RequestMapping(value = "preview", method = RequestMethod.GET)
+    public ResponseEntity<InputStreamResource> preview(@RequestParam String id, HttpServletResponse response) {
+        return edFileInfoService.preview(id, response);
+    }
 }

electrmangnetic/src/main/java/com/electromagnetic/industry/software/manage/service/EdFileInfoService.java

@@ -164,4 +164,11 @@ public interface EdFileInfoService {
      * @return
      */
     ElectromagneticResult<?> queryChildFolder(String parentId);
+
+    /**
+     * 文件预览
+     * @param id
+     * @param response
+     */
+    ResponseEntity<InputStreamResource> preview(String id, HttpServletResponse response);
 }

electrmangnetic/src/main/java/com/electromagnetic/industry/software/manage/service/serviceimpl/EdFileInfoServiceImpl.java

@@ -75,12 +75,14 @@ public class EdFileInfoServiceImpl extends ServiceImpl<EdFileInfoMapper, EdFileI
 
     private String downloadDataDir = "";
     private String uploadDataDir = "";
+    private String tmpDir = "";
 
     @PostConstruct
     public void init() {
         String osName = System.getProperty("os.name").toLowerCase();
         uploadDataDir = osName.startsWith("win") ? environment.getProperty("data.upload.windows.tmp.path") : environment.getProperty("data.upload.linux.tmp.path");
         downloadDataDir = osName.startsWith("win") ? environment.getProperty("data.download.windows.tmp.path") : environment.getProperty("data.download.linux.tmp.path");
+        tmpDir = osName.startsWith("win") ? environment.getProperty("data.windows.tmp.path") : environment.getProperty("data.linux.tmp.path");
     }
 
     /**
@@ -1195,4 +1197,44 @@ public class EdFileInfoServiceImpl extends ServiceImpl<EdFileInfoMapper, EdFileI
         return ElectromagneticResultUtil.success(res);
     }
 
+    /**
+     * 文件预览
+     *
+     * @param id
+     * @param response
+     */
+    @Override
+    public ResponseEntity<InputStreamResource> preview(String id, HttpServletResponse response) {
+        try {
+            EdFileInfo fileInfo = this.baseMapper.selectById(id);
+            Assert.isTrue(Objects.nonNull(fileInfo), "文件不存在");
+            String fileSysPath = commonService.getFileSysPath(fileInfo.getFilePath());
+            EleCommonUtil.decryptFile(fileSysPath, SecureUtil.aes(FILE_SEC_PASSWD.getBytes()));
+            if (Arrays.asList("doc", "docx").contains(fileInfo.getFileType())) {
+                String pdfTmpPath = tmpDir + File.separator + fileInfo.getFileName() + "_" + IdUtil.fastSimpleUUID() + ".pdf";
+                OfficeFileUtil.doc2pdf(fileSysPath, pdfTmpPath);
+                fileSysPath = pdfTmpPath;
+            }
+            FileSystemResource fileSystemResource = new FileSystemResource(fileSysPath);
+            String fileName = fileSystemResource.getFilename();
+            HttpHeaders headers = new HttpHeaders();
+            headers.add("Cache-Control", "no-cache, no-store, must-revalidate");
+            headers.add("Pragma", "no-cache");
+            headers.add("Expires", "0");
+            fileName = Base64.encode(fileName.substring(0, fileName.lastIndexOf(".")));
+            response.setHeader("content-disposition", "attachment;filename=" + fileName);
+            // 构建响应实体(可以返回<byte[]或Resource，返回类型取决body入参类型)
+            return ResponseEntity
+                    .ok()
+                    .headers(headers)
+                    .contentLength(fileSystemResource.contentLength())
+                    .contentType(MediaType.parseMediaType("application/octet-stream;charset=UTF-8"))
+                    .body(new InputStreamResource(fileSystemResource.getInputStream()));
+        } catch (Exception e) {
+            String info = StrFormatter.format("文件预览错误，文件id是--->{}，错误信息--->{}", id,e.getMessage());
+            log.error(info, e);
+            throw new BizException(info);
+        }
+    }
+
 }

electromagnetic-common/src/main/java/com/electromagnetic/industry/software/common/util/EleCommonUtil.java

@@ -57,13 +57,25 @@ public final class EleCommonUtil {
         return now.format(formatter);
     }
 
+    public static void decryptFile(String filePath, AES aes) {
+        handleFile(filePath, aes, false);
+    }
+
     public static void encryptFile(String filePath, AES aes) {
+        handleFile(filePath, aes, true);
+    }
+
+    private static void handleFile(String filePath, AES aes, boolean encrypt) {
         String tmpPath = filePath + ".tmp";
         try (
                 InputStream inputStream = Files.newInputStream(Paths.get(filePath));
                 OutputStream outputStream = Files.newOutputStream(Paths.get(tmpPath));
         ) {
+            if (encrypt) {
                 aes.encrypt(inputStream, outputStream, true);
+            } else {
+                aes.decrypt(inputStream, outputStream, true);
+            }
         } catch (Exception e) {
             String info = "文件加密失败";
             log.error(info, e);