I want to perform some batch operations in JCR (Jackrabit), I need to use org.apache.jackrabbit.spi.Batch (docs), for this I need RepositoryService but I do not know how to obtain the RepositoryService.
RepositoryService is a low-level interface, used by the Jackrabbit SPI interfaces.
In general, you do batch operations in JCR by do several operations and then calling Session.save().