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

maxFileCount <= 0

Error message

maxFileCount <= 0

What it means

DiskLruCache.open() throws IllegalArgumentException when maxFileCount is zero or negative. This variant of DiskLruCache enforces both a byte cap (maxSize) and a file-count cap, and a non-positive count cap is rejected outright. As with maxSize, the '0 = unlimited' convention is handled by the LruDiskCache wrapper, not here.

Source

Thrown at library/src/main/java/com/nostra13/universalimageloader/cache/disc/impl/ext/DiskLruCache.java:209

	}

	/**
	 * 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.

View on GitHub (pinned to ba33ec64d0)

Solutions

1. Pass a strictly positive file-count cap, e.g. 10000.
2. For effectively unlimited, pass Integer.MAX_VALUE (what LruDiskCache uses when cacheMaxFileCount == 0).
3. Use LruDiskCache/ImageLoaderConfiguration.diskCacheFileCount(...) instead of calling open() directly so 0 is normalized.

Example fix

// before
DiskLruCache.open(dir, appVersion, 1, maxSize, 0);

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

int effectiveCount = (maxFileCount > 0) ? maxFileCount : Integer.MAX_VALUE;
DiskLruCache.open(dir, appVersion, valueCount, maxSize, effectiveCount);

When it happens

Trigger: Calling DiskLruCache.open(directory, appVersion, valueCount, maxSize, 0) or with a negative count. Happens when callers reuse argument lists from the older 4-arg open() that had no file-count parameter.

Common situations: Migrating from an older UniversalImageLoader version whose DiskLruCache.open lacked maxFileCount and defaulting the new parameter to 0; config-driven values where the count field is unset and defaults to 0.

Related errors

• maxSize <= 0
• valueCount <= 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/a4ff133a79e56f9a. Report an issue: GitHub.