nostra13/Android-Universal-Image-Loader · error · IllegalArgumentException

valueCount <= 0

Error message

valueCount <= 0

What it means

DiskLruCache.open() throws IllegalArgumentException when valueCount is zero or negative. valueCount defines how many files each cache entry owns (keys map to valueCount files named key.0..key.N-1); at least one value per entry is required. The library itself always calls open() with valueCount = 1.

Source

Thrown at library/src/main/java/com/nostra13/universalimageloader/cache/disc/impl/ext/DiskLruCache.java:212

	 * Opens the cache in {@code directory}, creating a cache if none exists
	 * there.
	 *
	 * @param directory a writable directory
	 * @param valueCount the number of values per cache entry. Must be positive.
	 * @param maxSize the maximum number of bytes this cache should use to store
	 * @param maxFileCount the maximum file count this cache should store
	 * @throws IOException if reading or writing the cache directory fails
	 */
	public static DiskLruCache open(File directory, int appVersion, int valueCount, long maxSize, int maxFileCount)
			throws IOException {
		if (maxSize <= 0) {
			throw new IllegalArgumentException("maxSize <= 0");
		}
		if (maxFileCount <= 0) {
			throw new IllegalArgumentException("maxFileCount <= 0");
		}
		if (valueCount <= 0) {
			throw new IllegalArgumentException("valueCount <= 0");
		}

		// If a bkp file exists, use it instead.
		File backupFile = new File(directory, JOURNAL_FILE_BACKUP);
		if (backupFile.exists()) {
			File journalFile = new File(directory, JOURNAL_FILE);
			// If journal file also exists just delete backup file.
			if (journalFile.exists()) {
				backupFile.delete();
			} else {
				renameTo(backupFile, journalFile, false);
			}
		}

		// Prefer to pick up where we left off.
		DiskLruCache cache = new DiskLruCache(directory, appVersion, valueCount, maxSize, maxFileCount);
		if (cache.journalFile.exists()) {
			try {

View on GitHub (pinned to ba33ec64d0)

Solutions

1. Pass 1 for valueCount unless you deliberately implement multi-file entries.
2. Audit custom DiskLruCache wrappers for hardcoded zeros in the open() call.
3. Prefer LruDiskCache, which always uses valueCount = 1 internally.

Example fix

// before
DiskLruCache.open(dir, appVersion, 0, maxSize, maxFileCount);

// after
DiskLruCache.open(dir, appVersion, 1, maxSize, maxFileCount);

if (valueCount <= 0) throw new IllegalArgumentException("valueCount must be >= 1, got " + valueCount);
DiskLruCache.open(dir, appVersion, valueCount, maxSize, maxFileCount);

When it happens

Trigger: Calling DiskLruCache.open(directory, appVersion, 0, maxSize, maxFileCount) or with a negative valueCount. In this codebase the only production call site (LruDiskCache.initDiskCache) passes 1, so hitting it means custom code called open() directly with a computed or hardcoded 0.

Common situations: Copy-pasting an open() call and zeroing parameters you don't understand; deriving valueCount from a multi-file entry scheme that computed 0 entries; adapting an older sample that omitted the parameter.

Related errors

• maxSize <= 0
• maxFileCount <= 0
• cacheMaxSize argument must be positive number
• cacheMaxFileCount argument must be positive number
• keys must match regex [a-z0-9_-]{1,64}: "{key}"

AI-assisted analysis of nostra13/Android-Universal-Image-Loader@ba33ec64d0 (2026-08-14). Data as JSON: /api/errors/0b294ad00351a239. Report an issue: GitHub.