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[PerilousApricot]

There was/is the famous problem where the hadoop adaptor can't link to xrootd libraries compiled with a different C++ API.

Newer versions of the xrootd libraries have a form of Open() that accepts a char * instead of an std::string - xrootd/xrootd#1010 .. If this is added with some sort of runtime checking (e.g. use char* if it exists, fall back to std::string otherwise), it'll be possible to have a library usable anywhere

[mrow4a]

ok, I see Michal indeed added the support in xrootd/xrootd@55e52ce so it should be in v4.10.0 and up.

[PerilousApricot]

Hi Piotr, I actually found an easier solution that works on all versions. Construct an XrdPosixFile on the heap via new() https://github.com/xrootd/xrootd/blob/7476545ae9f1301409b8c3503cb28b672bb34589/src/XrdPosix/XrdPosixFile.cc#L91 Which accepts a char* and then pull the clFile member from XrdPosixFile (which is helpfully public) https://github.com/xrootd/xrootd/blob/7476545ae9f1301409b8c3503cb28b672bb34589/src/XrdPosix/XrdPosixFile.hh#L65 Then just make sure to delete the XrdPosixFile when java calls close so the destructor happens https://github.com/xrootd/xrootd/blob/7476545ae9f1301409b8c3503cb28b672bb34589/src/XrdPosix/XrdPosixFile.cc#L123 No function calls from Hadoop-xrootd have STL objects as arguments, so the link problem goes away! -- It's dark in this basement.