feat：增强文件预览功能

- 新增视频文件预览
- 新增Pdf文件预览

upload-file-backend/src/main/java/cn/czh/controller/FileController.java

@@ -4,8 +4,9 @@ import cn.czh.base.Result;
 import cn.czh.entity.StorageConfig;
 import cn.czh.service.IFileService;
 import cn.czh.service.IStorageConfigService;
+import cn.czh.utils.FileTypeUtil;
+import org.springframework.core.io.ByteArrayResource;
 import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -18,6 +19,7 @@ import javax.servlet.http.HttpServletRequest;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.Paths;
 
 @RestController
 @RequestMapping("/file")
@@ -29,7 +31,7 @@ public class FileController {
     private IFileService fileService;
 
     @GetMapping("/preview/{storageType}/**")
-    public ResponseEntity<byte[]> previewFile(
+    public ResponseEntity<?> previewFile(
             @PathVariable String storageType,
             HttpServletRequest request) throws IOException {
         // 从请求中提取剩余路径作为 objectKey
@@ -39,16 +41,37 @@ public class FileController {
 
         if (StorageConfig.LOCAL.equals(storageType)) {
             StorageConfig storageConfig = storageConfigService.getStorageConfigByType(storageType);
-            String filePath = storageConfig.getBucket() + "\\" + objectKey;
+            // 使用 Paths.get 拼接路径，避免反斜杠问题
+            String filePath = Paths.get(storageConfig.getBucket(), objectKey).toString();
             File file = new File(filePath);
+
+            // 检查文件是否存在
             if (!file.exists()) {
                 return ResponseEntity.notFound().build();
             }
+
+            // 读取文件内容
             byte[] fileBytes = Files.readAllBytes(file.toPath());
+            ByteArrayResource resource = new ByteArrayResource(fileBytes);
+
+            // 设置响应头
             HttpHeaders headers = new HttpHeaders();
-            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
-            return new ResponseEntity<>(fileBytes, headers, HttpStatus.OK);
+            String fileName = file.getName().toLowerCase();
+            String fileSuffix = FileTypeUtil.getFileSuffix(fileName).toLowerCase();
+
+            // 根据文件类型设置 Content-Type
+            MediaType contentType = FileTypeUtil.determineContentType(fileSuffix);
+            headers.setContentType(contentType);
+
+            // 设置 Content-Disposition 为 inline，浏览器直接预览
+            headers.add(HttpHeaders.CONTENT_DISPOSITION, "inline; filename=\"" + file.getName() + "\"");
+            headers.setContentLength(fileBytes.length);
+
+            return ResponseEntity.ok()
+                    .headers(headers)
+                    .body(resource);
         }
+
         return ResponseEntity.badRequest().build();
     }
 

upload-file-backend/src/main/java/cn/czh/utils/FileTypeUtil.java

@@ -1,5 +1,7 @@
 package cn.czh.utils;
 
+import org.springframework.http.MediaType;
+
 /**
  * 文件类型的工具类
  */
@@ -158,4 +160,61 @@ public class FileTypeUtil {
         }
 		return false;
 	}
+
+	/**
+	 * 根据文件后缀确定 Content-Type
+	 */
+	public static MediaType determineContentType(String fileSuffix) {
+		// 使用 FileTypeUtil 判断文件类型
+		if (FileTypeUtil.isImgType(fileSuffix)) {
+			switch (fileSuffix) {
+				case "jpg":
+				case "jpeg":
+					return MediaType.IMAGE_JPEG;
+				case "png":
+					return MediaType.IMAGE_PNG;
+				case "gif":
+					return MediaType.IMAGE_GIF;
+				default:
+					return MediaType.APPLICATION_OCTET_STREAM;
+			}
+		} else if (FileTypeUtil.bVideoFileType("example." + fileSuffix)) {
+			switch (fileSuffix) {
+				case "mp4":
+					return MediaType.valueOf("video/mp4");
+				case "avi":
+					return MediaType.valueOf("video/x-msvideo");
+				case "wmv":
+					return MediaType.valueOf("video/x-ms-wmv");
+				default:
+					return MediaType.APPLICATION_OCTET_STREAM;
+			}
+		} else if (FileTypeUtil.bAudioFileType("example." + fileSuffix)) {
+			switch (fileSuffix) {
+				case "mp3":
+					return MediaType.valueOf("audio/mpeg");
+				case "wav":
+					return MediaType.valueOf("audio/wav");
+				default:
+					return MediaType.APPLICATION_OCTET_STREAM;
+			}
+		} else if (FileTypeUtil.bLogFileType("example." + fileSuffix)) {
+			switch (fileSuffix) {
+				case "txt":
+					return MediaType.TEXT_PLAIN;
+				case "log":
+					return MediaType.valueOf("text/plain");
+				case "doc":
+				case "docx":
+					return MediaType.valueOf("application/msword");
+				default:
+					return MediaType.APPLICATION_OCTET_STREAM;
+			}
+		} else if ("pdf".equals(fileSuffix)) {
+			return MediaType.APPLICATION_PDF;
+		}
+
+		// 默认类型
+		return MediaType.APPLICATION_OCTET_STREAM;
+	}
 }