Memory leak in wildfly transaction client

        XAResourceRegistryFile(Xid xid) throws SystemException {
            xaRecoveryPath.toFile().mkdir(); // create dir if non existent
            final String xidString = SimpleXid.of(xid).toHexString('_');
            this.filePath = xaRecoveryPath.resolve(xidString);
            openFilePaths.add(*xidString*);

        protected void removeResource(XAResource resource) throws XAException {
            if (resources.remove(resource)) {
                if (resources.isEmpty()) {
                    // delete file
                    try {
                        if (fileChannel != null) {
                            fileChannel.close();
                        }
                        Files.delete(filePath);
                        // deleting using the filepath as key caused a memory leak,
                        // if xid string have been added, therefore build the xid string for removing
                        openFilePaths.remove(*filePath.toString()*);
 

                        String xidString = filePath.toString().substring(filePath.toString().indexOf(
                        		xaRecoveryPath.toString()) + xaRecoveryPath.toString().length() + 1);
                        openFilePaths.remove(xidString);