java-把File转成MultipartFile

最新推荐文章于 2025-06-18 10:35:30 发布

bleach777

最新推荐文章于 2025-06-18 10:35:30 发布

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分类专栏： java

原文链接：https://blog.youkuaiyun.com/qq_34542964/article/details/72461246

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本文介绍了一种将本地文件路径转换为MultipartFile的方法，适用于Java Spring Boot框架中处理文件上传的需求。通过创建FileItem并封装为CommonsMultipartFile，实现了从文件路径到MultipartFile的转换，便于进行文件上传操作。

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	// 把File转成MultipartFile
	private static MultipartFile getMulFileByPath(String picPath) {
		FileItem fileItem = createFileItem(picPath);
		MultipartFile mfile = new CommonsMultipartFile(fileItem);
		return mfile;
	}

	private static FileItem createFileItem(String filePath) {
		FileItemFactory factory = new DiskFileItemFactory(16, null);
		String textFieldName = "textField";
		int num = filePath.lastIndexOf(".");
		String extFile = filePath.substring(num);
		FileItem item = factory.createItem(textFieldName, "text/plain", true, "MyFileName" + extFile);
		File newfile = new File(filePath);
		int bytesRead = 0;
		byte[] buffer = new byte[8192];
		try {
			FileInputStream fis = new FileInputStream(newfile);
			OutputStream os = item.getOutputStream();
			while ((bytesRead = fis.read(buffer, 0, 8192)) != -1) {
				os.write(buffer, 0, bytesRead);
			}
			os.close();
			fis.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return item;
	}

	// 测试
	@PostMapping("/testtest")
	public String testtest(@RequestParam("path") String path) throws FileNotFoundException {

		MultipartFile multipartFile = getMulFileByPath(path);

		String fullpath = "C:\\Users\\jiangyafen\\Desktop\\imageTest\\test";
		// 保存图片
		try {
			// MultipartFile转byte
			byte[] img = multipartFile.getBytes();

			File file = new File(fullpath);
			if (!file.getParentFile().exists()) {
				file.getParentFile().mkdirs();
			}
			FileImageOutputStream imageOutput = new FileImageOutputStream(file);
			imageOutput.write(img, 0, img.length);
			Thumbnails.of(file).scale(0.5).toFile(fullpath);
			imageOutput.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			throw new AppBizException(e.getLocalizedMessage());
		}

		return "scuess";
	}