chinabugotech/hutool · error · IllegalArgumentException

Paths length is not equals to ins length !

Error message

Paths length is not equals to ins length !

What it means

ZipWriter.add(String[] paths, InputStream[] ins) requires paths.length == ins.length so each path maps to exactly one stream. A mismatch throws IllegalArgumentException.

Source

Thrown at hutool-core/src/main/java/cn/hutool/core/compress/ZipWriter.java:198

		return putEntry(path, in);
	}

	/**
	 * 对流中的数据加入到压缩文件<br>
	 * 路径列表和流列表长度必须一致
	 *
	 * @param paths 流数据在压缩文件中的路径或文件名
	 * @param ins   要压缩的源，添加完成后自动关闭流
	 * @return 压缩文件
	 * @throws IORuntimeException IO异常
	 * @since 5.8.0
	 */
	public ZipWriter add(String[] paths, InputStream[] ins) throws IORuntimeException {
		if (ArrayUtil.isEmpty(paths) || ArrayUtil.isEmpty(ins)) {
			throw new IllegalArgumentException("Paths or ins is empty !");
		}
		if (paths.length != ins.length) {
			throw new IllegalArgumentException("Paths length is not equals to ins length !");
		}

		for (int i = 0; i < paths.length; i++) {
			add(paths[i], ins[i]);
		}

		return this;
	}

	@Override
	public void close() throws IORuntimeException {
		try {
			out.finish();
		} catch (IOException e) {
			throw new IORuntimeException(e);
		} finally {
			IoUtil.close(this.out);
		}

View on GitHub (pinned to 8870454b2a)

Solutions

1. Derive both arrays from the same source list (e.g. List<File> -> split into paths and InputStreams) so lengths always match.
2. Assert paths.length == ins.length before calling add.
3. Switch to the single-entry add(path, in) inside a loop indexed over one source.

Example fix

// before - arrays can drift
writer.add(pathArr, streamArr);

// after - one loop, one source
for (File f : files) {
    writer.add(f.getName(), new FileInputStream(f));
}

if (paths.length != ins.length) {
    throw new IllegalStateException("paths/ins length mismatch: " + paths.length + " vs " + ins.length);
}
writer.add(paths, ins);

try {
    writer.add(paths, ins);
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("not equals")) { /* reconcile arrays */ }
    else throw e;
}

When it happens

Trigger: Calling the bulk add with two parallel arrays of different lengths, e.g. 3 paths and 2 streams.

Common situations: Maintaining two parallel arrays from independent sources that drift out of sync; off-by-one filtering applied to one array but not the other.

Related errors

• Paths or ins is empty !
• Video URI is empty
• File not found!
• Base58 checksum is invalid
• Index [{}] is too large for limit: [{}]

AI-assisted analysis of chinabugotech/hutool@8870454b2a (2026-08-14). Data as JSON: /api/errors/cffc68f98e550052. Report an issue: GitHub.