chinabugotech/hutool · error · IllegalArgumentException

给定文件为空

Error message

给定文件为空

What it means

BackgroundRemoval.fileTypeValidation throws IllegalArgumentException ('给定文件为空' = 'the given file is empty/missing') when the File passed to it does not exist (input.exists() is false). Despite the word 'empty', the actual condition is non-existence.

Source

Thrown at hutool-core/src/main/java/cn/hutool/core/img/BackgroundRemoval.java:344

			return ImgUtil.toHex(Integer.parseInt(strings[0]), Integer.parseInt(strings[1]),
					Integer.parseInt(strings[2]));
		}
		return StrUtil.EMPTY;
	}

	// -------------------------------------------------------------------------- private

	/**
	 * 文件类型验证
	 * 根据给定文件类型数据，验证给定文件类型.
	 *
	 * @param input      需要进行验证的文件
	 * @param imagesType 文件包含的类型数组
	 * @return 返回布尔值 false:给定文件的文件类型在文件数组中  true:给定文件的文件类型 不在给定数组中。
	 */
	private static boolean fileTypeValidation(File input, String[] imagesType) {
		if (!input.exists()) {
			throw new IllegalArgumentException("给定文件为空");
		}
		// 获取图片类型
		String type = FileTypeUtil.getType(input);
		// 类型对比
		if (!ArrayUtil.contains(imagesType, type)) {
			throw new IllegalArgumentException(StrUtil.format("文件类型{}不支持", type));
		}
		return false;
	}
}

View on GitHub (pinned to 8870454b2a)

Solutions

1. Verify input.exists() && input.isFile() before calling the removal method.
2. Resolve paths to absolute and log them to catch typos / wrong working directory.
3. Ensure the file is present (re-download, recreate) before processing.

Example fix

// before
BackgroundRemoval.removeBg(new File("/tmp/missing.png"), ...);
// after
File f = new File("/tmp/missing.png");
if (!f.isFile()) throw new FileNotFoundException(f.getAbsolutePath());
BackgroundRemoval.removeBg(f, ...);

void requireExistingImage(File f){ if(f==null || !f.exists() || !f.isFile()) throw new FileNotFoundException(String.valueOf(f)); }

boolean isReadableFile(File f){ return f != null && f.exists() && f.isFile() && f.canRead(); }

try { BackgroundRemoval.removeBg(file, ...); }
catch (IllegalArgumentException e){ if(e.getMessage().contains("给定文件为空")) { /* report missing path */ } else throw e; }

When it happens

Trigger: Calling a background-removal method with a File whose path does not exist, points to a deleted/moved file, or has a typo in the path.

Common situations: User-uploaded file already cleaned up; path from config that is wrong; file on a network mount that is unavailable; relative path resolved against the wrong working directory.

Related errors

• 图片流是空的
• 文件类型{}不支持
• Destination Dir must be a Directory !
• RGB must be 0~255!
• Image type of file [{}] is not supported!

AI-assisted analysis of chinabugotech/hutool@8870454b2a (2026-08-14). Data as JSON: /api/errors/c6b1b7e28819e7da. Report an issue: GitHub.