MuntashirAkon/AppManager · error · IllegalArgumentException

blockSize(" + blockSize + ") < 1

Error message

blockSize(" + blockSize + ") < 1

What it means

The BZip2CompressorOutputStream(out, blockSize) constructor requires a blockSize100k parameter between 1 and 9 (meaning 100k–900k blocks). Passing 0 or a negative number is rejected immediately with this IllegalArgumentException — it is a programming/config error, not an I/O problem.

Source

Thrown at app/src/main/java/org/apache/commons/compress/compressors/bzip2/BZip2CompressorOutputStream.java:366

     *
     * @param out
     *            the destination stream.
     * @param blockSize
     *            the blockSize as 100k units.
     *
     * @throws IOException
     *             if an I/O error occurs in the specified stream.
     * @throws IllegalArgumentException
     *             if <code>(blockSize &lt; 1) || (blockSize &gt; 9)</code>.
     * @throws NullPointerException
     *             if <code>out == null</code>.
     *
     * @see #MIN_BLOCKSIZE
     * @see #MAX_BLOCKSIZE
     */
    public BZip2CompressorOutputStream(final OutputStream out, final int blockSize) throws IOException {
        if (blockSize < 1) {
            throw new IllegalArgumentException("blockSize(" + blockSize + ") < 1");
        }
        if (blockSize > 9) {
            throw new IllegalArgumentException("blockSize(" + blockSize + ") > 9");
        }

        this.blockSize100k = blockSize;
        this.out = out;

        /* 20 is just a paranoia constant */
        this.allowableBlockSize = (this.blockSize100k * BZip2Constants.BASEBLOCKSIZE) - 20;
        init();
    }

    @Override
    public void write(final int b) throws IOException {
        if (closed) {
            throw new IOException("Closed");
        }

View on GitHub (pinned to 0152f468fc)

Solutions

1. Pass a blockSize between 1 and 9, or use the single-argument constructor BZip2CompressorOutputStream(out) which uses the default.
2. Clamp or default invalid configured values before constructing (Math.max(1, Math.min(9, value))).
3. If blockSize comes from config, validate it at startup with a clear message.

Example fix

// before
int blockSize = Integer.parseInt(cfg.get("blocksize")); // 0 when unset
BZip2CompressorOutputStream out = new BZip2CompressorOutputStream(os, blockSize);
// after
int blockSize = Math.max(1, Math.min(9, Integer.parseInt(cfg.getOrDefault("blocksize", "9"))));
BZip2CompressorOutputStream out = new BZip2CompressorOutputStream(os, blockSize);

// validate before constructing
if (blockSize < 1 || blockSize > 9)
    throw new IllegalArgumentException("blockSize must be 1..9, got " + blockSize);

try {
    out = new BZip2CompressorOutputStream(os, configuredBlockSize);
} catch (IllegalArgumentException e) {
    out = new BZip2CompressorOutputStream(os); // fall back to default
    log.warn("bad blockSize config, using default", e);
}

When it happens

Trigger: new BZip2CompressorOutputStream(out, 0) or any negative blockSize; typically blockSize read from config/env that defaulted to 0.

Common situations: Config property like 'compress.blocksize' missing or parsed to 0, user-supplied value not clamped, refactored code passing an uninitialized int.

Related errors

• blockSize(" + blockSize + ") > 9
• Block size must be a multiple of 512 bytes. Attempt to use s
• The app has keystore items and KeyStore backup isn't enabled
• Data directory cannot be empty.
• Invalid source compression type:

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/c80819717a015c75. Report an issue: GitHub.