spring-projects/spring-boot · error · IllegalStateException

File '{}' is not readable

Error message

File '{}' is not readable

What it means

ZipFileTarArchive.assertArchiveHasEntries opens the source file with Apache Commons Compress ZipFile.builder().setFile(file).get(). Any IOException — file missing, not a zip, truncated/corrupted, encrypted, or unreadable — is wrapped in IllegalStateException('File <file> is not readable'). This runs in the constructor, so failure prevents the ZipFileTarArchive from being created.

Source

Thrown at buildpack/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/io/ZipFileTarArchive.java:83

	public void writeTo(OutputStream outputStream) throws IOException {
		TarArchiveOutputStream tar = new TarArchiveOutputStream(outputStream);
		tar.setLongFileMode(TarArchiveOutputStream.LONGFILE_POSIX);
		try (ZipFile zipFile = ZipFile.builder().setFile(this.zip).get()) {
			Enumeration<ZipArchiveEntry> entries = zipFile.getEntries();
			while (entries.hasMoreElements()) {
				ZipArchiveEntry zipEntry = entries.nextElement();
				copy(zipEntry, zipFile.getInputStream(zipEntry), tar);
			}
		}
		tar.finish();
	}

	private void assertArchiveHasEntries(File file) {
		try (ZipFile zipFile = ZipFile.builder().setFile(file).get()) {
			Assert.state(zipFile.getEntries().hasMoreElements(), () -> "Archive file '" + file + "' is not valid");
		}
		catch (IOException ex) {
			throw new IllegalStateException("File '" + file + "' is not readable", ex);
		}
	}

	private void copy(ZipArchiveEntry zipEntry, InputStream zip, TarArchiveOutputStream tar) throws IOException {
		TarArchiveEntry tarEntry = convert(zipEntry);
		tar.putArchiveEntry(tarEntry);
		if (tarEntry.isFile()) {
			StreamUtils.copyRange(zip, tar, 0, tarEntry.getSize());
		}
		tar.closeArchiveEntry();
	}

	private TarArchiveEntry convert(ZipArchiveEntry zipEntry) {
		byte linkFlag = (zipEntry.isDirectory()) ? TarConstants.LF_DIR : TarConstants.LF_NORMAL;
		String entryName = zipEntry.getName();
		Path entryPath = Path.of(entryName);
		Assert.state(entryPath.toAbsolutePath().equals(entryPath.toAbsolutePath().normalize()),
				() -> "Malformed zip entry name '%s'".formatted(entryName));

View on GitHub (pinned to 270dfe353f)

Solutions

1. Confirm it is a valid zip: `unzip -l <file>` or `jar tf <file>`.
2. Re-generate the archive from the source build.
3. Fix read permissions: `chmod +r <file>` and check SELinux labels.

// Validate the source zip before constructing ZipFileTarArchive
if (!Files.exists(file.toPath()) || !Files.isReadable(file.toPath())) {
    throw new IllegalArgumentException("Zip file missing or unreadable: " + file);
}
try (org.apache.commons.compress.archivers.zip.ZipFile zf =
        ZipFile.builder().setFile(file).get()) {
    if (!zf.getEntries().hasMoreElements()) {
        throw new IllegalArgumentException("Zip file has no entries: " + file);
    }
}

try {
    new ZipFileTarArchive(file, owner);
} catch (IllegalStateException ex) {
    if (ex.getCause() instanceof IOException
            && ex.getMessage().startsWith("File '") && ex.getMessage().endsWith("is not readable")) {
        // hint: validate with `unzip -l <file>` / regenerate the archive
    }
    throw ex;
}

When it happens

Trigger: new ZipFileTarArchive(file, owner) or TarArchive.fromZip(file, owner) is called with a File that ZipFile cannot open: the file does not exist, is not a zip, is a truncated/corrupted zip, is encrypted, or has read permissions denied.

Common situations: Wrong path to the application archive; a jar/zip corrupted in transfer or by a failed build; file permission denied (chmod, SELinux); an AES-encrypted zip; a file that is actually a tar or plain file.

Related errors

• Error reading Docker configuration file '{}'
• Error creating KeyStore: {}
• zstd compression is not supported
• Failed to create {}
• Failed to add {} to {}

AI-assisted analysis of spring-projects/spring-boot@270dfe353f (2026-08-11). Data as JSON: /api/errors/e6ac76a5655045fe. Report an issue: GitHub.