Blankj/AndroidUtilCode · error · IllegalArgumentException

precision shouldn't be less than zero!

Error message

precision shouldn't be less than zero!

What it means

ConvertUtils.byte2FitMemorySize(long, int) formats a byte count into a human-readable B/KB/MB/GB string with a caller-specified number of decimal places. A negative precision is meaningless for String.format("%.Nf...") and would produce a FormatFlagsConversionMismatchException / UnknownFormatConversionException, so the method fails fast with IllegalArgumentException instead.

Source

Thrown at lib/utilcode/src/main/java/com/blankj/utilcode/util/ConvertUtils.java:470

     * @return fit size of memory
     */
    @SuppressLint("DefaultLocale")
    public static String byte2FitMemorySize(final long byteSize) {
        return byte2FitMemorySize(byteSize, 3);
    }

    /**
     * Size of byte to fit size of memory.
     * <p>to three decimal places</p>
     *
     * @param byteSize  Size of byte.
     * @param precision The precision
     * @return fit size of memory
     */
    @SuppressLint("DefaultLocale")
    public static String byte2FitMemorySize(final long byteSize, int precision) {
        if (precision < 0) {
            throw new IllegalArgumentException("precision shouldn't be less than zero!");
        }
        if (byteSize < 0) {
            throw new IllegalArgumentException("byteSize shouldn't be less than zero!");
        } else if (byteSize < MemoryConstants.KB) {
            return String.format("%." + precision + "fB", (double) byteSize);
        } else if (byteSize < MemoryConstants.MB) {
            return String.format("%." + precision + "fKB", (double) byteSize / MemoryConstants.KB);
        } else if (byteSize < MemoryConstants.GB) {
            return String.format("%." + precision + "fMB", (double) byteSize / MemoryConstants.MB);
        } else {
            return String.format("%." + precision + "fGB", (double) byteSize / MemoryConstants.GB);
        }
    }

    /**
     * Time span in unit to milliseconds.
     *
     * @param timeSpan The time span.

View on GitHub (pinned to 7b4caf9e54)

Solutions

1. Coerce the precision to a non-negative value before calling: use Math.max(0, precision), or default to 0/2 when the source value is negative/unset.
2. Treat the -1 sentinel from your config as 'use default precision' and substitute a sensible constant (e.g. 2).
3. Validate at the boundary that produced the precision and reject the input there instead of letting it reach byte2FitMemorySize.
4. If you truly need 'no decimals', pass precision = 0 rather than a negative number.

Example fix

// before
String s = ConvertUtils.byte2FitMemorySize(fileLen, precisionFromConfig); // precisionFromConfig == -1

// after
int precision = precisionFromConfig < 0 ? 2 : precisionFromConfig;
String s = ConvertUtils.byte2FitMemorySize(fileLen, precision);

// Validate precision before formatting
int precision = precisionFromConfig;
if (precision < 0) {
    precision = 2; // or 0 for no decimals
}
String s = ConvertUtils.byte2FitMemorySize(byteSize, precision);

// Coerce/validate the precision integer before the call
public static int safePrecision(int p) {
    return p < 0 ? 2 : p;
}

try {
    String s = ConvertUtils.byte2FitMemorySize(byteSize, precision);
} catch (IllegalArgumentException e) {
    // precision (or byteSize) was negative; clamp and retry once
    String s = ConvertUtils.byte2FitMemorySize(Math.max(0, byteSize), Math.max(0, precision));
}

When it happens

Trigger: Calling byte2FitMemorySize(size, precision) with a precision argument that is negative, typically because a configurable format setting defaulted to -1 (meaning 'unset'), or because an unsigned field was modelled as a signed int and underflowed.

Common situations: Reading precision from a config/SharedPreferences where the default sentinel is -1; arithmetic on lengths that goes negative; passing a 'decimals' value from an API that uses -1 to mean 'not specified'; copy-paste from a percentage formatter that allowed negatives.

Related errors

• byteSize shouldn't be less than zero!
• The key is null.
• The duration is less than 0.
• key must be between 1 and 256 bytes
• comparator must not be null

AI-assisted analysis of Blankj/AndroidUtilCode@7b4caf9e54 (2026-08-14). Data as JSON: /api/errors/0e00304f53a15b87. Report an issue: GitHub.