apache/flink · error · NullPointerException

Read buffer must not be null

Error message

Read buffer must not be null

What it means

Error "Read buffer must not be null" thrown in apache/flink.

Source

Thrown at flink-filesystems/flink-s3-fs-native/src/main/java/org/apache/flink/fs/s3native/NativeS3InputStream.java:309

                return -1;
            }
            lazySeek();
            ensureStreamOpen();
            int data = bufferedStream.read();
            if (data != -1) {
                nextReadPos++;
                streamPos++;
            }
            return data;
        } finally {
            lock.unlock();
        }
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (b == null) {
            throw new NullPointerException("Read buffer must not be null");
        }
        if (off < 0 || len < 0 || len > b.length - off) {
            throw new IndexOutOfBoundsException(
                    String.format(
                            "Range [off=%d, len=%d] out of bounds for buffer of length %d",
                            off, len, b.length));
        }
        if (len == 0) {
            return 0;
        }
        lock();
        try {
            if (closed) {
                throw new IOException("Stream is closed");
            }
            if (nextReadPos >= contentLength) {
                return -1;
            }

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Address the cause reported by the error message: Read buffer must not be null
2. Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry.

Example fix

Correct the condition described ("Read buffer must not be null") and rerun the job or command.

When it happens

Trigger: Triggered at runtime when the operation fails because: Read buffer must not be null.

Common situations: Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: Read buffer must not be null.

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/7087ede0e4f02e29. Report an issue: GitHub.