Read-only view of ByteArrayInputStream content

[Martin Desruisseaux]

Hello

JDK-22 has modified ByteArrayInputStream.transferTo(OutputStream) 
implementation for performing a defensive copy of the byte array when 
the destination is not trusted (JDK-8321053). However, I was using the 
previous implementation as a trick for reading the array without copy. 
The reason is because we have millions of ByteArrayInputStream instances 
when reading BLOBs from a database (e.g., geometries from a spatial 
database), and some popular JDBC drivers implement 
ResultSet.getBinaryStream(int) by reading all data in a byte[] array and 
wrapping the array in a ByteArrayInputStream. As a cleaner replacement 
for my old trick, would it be possible to add something like the 
following method in ByteArrayInputStream?

    /** * Returns the remaining content of this input stream as a
    read-only buffer. * The sequence of remaining bytes in the buffer is
    the same as the sequence * of bytes that would be returned by {@link
    #readAllBytes()}. * * @return the remaining content of this input
    stream, as a read-only buffer */ public synchronized ByteBuffer
    asByteBuffer() { return ByteBuffer.wrap(buf, pos, count -
    pos).slice().asReadOnlyBuffer(); }

The call to slice() is for blocking callers from accessing the bytes 
before the current stream position. I assumed that it could be a 
security issue. If this proposal is acceptable, I can create a pull request.

     Thanks,

         Martin

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/core-libs-dev/attachments/20240709/7bb8268d/attachment.htm>