What causes "The given bytes are null" in apache/pulsar?

Pass a non-null allocated buffer, e.g. new byte[blockSize]

apache/pulsar · error · NullPointerException

The given bytes are null

Error message

The given bytes are null

What it means

BlockAwareSegmentInputStreamImpl.read(byte[], int, int) validates its arguments per the InputStream contract. A null buffer is rejected immediately with NullPointerException("The given bytes are null").

Source

Thrown at tiered-storage/jcloud/src/main/java/org/apache/bookkeeper/mledger/offload/jcloud/impl/BlockAwareSegmentInputStreamImpl.java:221

                entryHeaderBuf.writeInt(entryLength).writeLong(entryId);
                entryBuf.addComponents(true, entryHeaderBuf, buf);

                entries.add(entryBuf);
            }
            return entries;
        } catch (InterruptedException | ExecutionException e) {
            log.error().exception(e).log("Exception when getting LedgerEntries");
            if (e instanceof InterruptedException) {
                Thread.currentThread().interrupt();
            }
            throw new IOException(e);
        }
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (b == null) {
            throw new NullPointerException("The given bytes are null");
        } else if (off < 0 || len < 0 || len > b.length - off) {
            throw new IndexOutOfBoundsException("off=" + off + ", len=" + len + ", b.length=" + b.length);
        } else if (len == 0) {
            return 0;
        }

        int offset = off;
        int readLen = len;
        int readBytes = 0;
        // reading header
        if (dataBlockHeaderStream.available() > 0) {
            int read = dataBlockHeaderStream.read(b, off, len);
            offset += read;
            readLen -= read;
            readBytes += read;
            bytesReadOffset += read;
        }
        if (readLen == 0) {

View on GitHub (pinned to 820761864e)

Solutions

Pass a non-null allocated buffer, e.g. new byte[blockSize]
Audit the calling code path for uninitialized buffer variables
Check wrapper/copy utilities that may pass null through to read()

Example fix

// before
stream.read(null, 0, len); // NPE
// after
byte[] buf = new byte[len];
int n = stream.read(buf, 0, len);

Defensive patterns

Strategy: type-guard

Validate before calling

if (b == null) throw new IllegalArgumentException("buffer must not be null");
// then call read safely
int n = stream.read(b, off, len);

Type guard

static boolean safeBuffer(byte[] b) { return b != null; }
// usage: if (!safeBuffer(buf)) allocateOrReject();

Try / catch

try {
  int n = stream.read(buf, off, len);
} catch (NullPointerException e) {
  if ("The given bytes are null".equals(e.getMessage())) {
    buf = new byte[len]; n = stream.read(buf, off, len);
  } else throw e;
}

Prevention

Initialize buffers explicitly before read loops
Run static analysis / null-checks on wrapper stream code
Don't forward buffers from callers that may return null

When it happens

Trigger: Calling read(null, off, len) on the segment input stream — the buffer parameter was never initialized or was set to null by the caller.

Common situations: Caller bug passing an uninitialized byte[] when copying a block to the offload output; wrapper streams forwarding a null buffer obtained elsewhere.

Related errors

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/b91d08f489ccb09f. Report an issue: GitHub.