Building JInterface for Clojure
Erlang and JInterface
Getting Erlang, JInterface, and Clojure working together can be tricky just for the simple fact that the JInterface .jar files tend to be a mismatched mess. I’ve tried to help out with this by publishing what seem to be working JInterface .jar files on Clojars. I don’t have the infrastructure available for testing all of these, so feedback is welcome.
To make this easier for devs to do themselves, this project includes some make targets for building JInterface .jar files. Also, a table is proivded below to help match Erlang VM with the right JInterface relase.
A Note on Versions
JInterface is only guaranteed to work with the version of Erlang with which it was released. The following version numbers are paired:
| Erlang Release | Erlang Version (erts) | JInterface |
|---|---|---|
| 18.2 | 7.2 | 1.6.1 |
| 18.1 | 7.1 | 1.6 |
| 18.0 | 7.0 | 1.6 |
| 17.5 | 6.4 | 1.5.12 |
| 17.4 | 6.3 | 1.5.11 |
| 17.3 | 6.2 | 1.5.10 |
| 17.2 | 6.1 | 1.5.9 |
| 17.1 | 6.1 | 1.5.9 |
| 17.0 | 6.0 | 1.5.9 |
| R16B03 | 5.10.4 | 1.5.8 |
| R16B02 | 5.10.3 | 1.5.8 |
| R16B01 | 5.10.2 | 1.5.8 |
| R16B | 5.10.1 | 1.5.8 |
| R15B03 | 5.9.3 | 1.5.6 |
| R15B02 | 5.9.2 | 1.5.6 |
| R15B01 | 5.9.1 | 1.5.6 |
| R15B | 5.9 | 1.5.5 |
Building JInterface
To ensure that your version of JInterface is ready for use by Clojure with your version of Erlang, simply do this:
$ make jinterface-local
This will discover the Erlang root directory for the first erl found in your PATH. It will also location the JInterface .jar file for that version of Erlang.
If you wish to override these, you may do the following:
$ make jinterface-local ERL_LIBS=/opt/erlang/15.3.1
This make target (which depends upon Maven being installed) will generate a lein-friendly .jar file for you in your ~/.m2/repository directory, just like lein does with downloaded Clojars.
Finding Your Root Dir
If you don’t know what your Erlang root directory is, just fire up Erlang and do the following:
$ erl
1> code:root_dir().
"/opt/erlang/18.2"
The Makefile uses this to get the default Erlang root directory:
ERL_LIBS=$(erl -eval "io:format(code:root_dir()),halt()" -noshell)
Getting Versions
The Makefile provides a convenience target for getting some important version numbers:
$ make show-versions
Project: clojang, 0.1.0
Erlang: Erlang/OTP 18 [erts-7.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
JInterface: 1.6.1
Clojure: 1.7.0
lein/JVM: Leiningen 2.5.3 on Java 1.7.0_91 OpenJDK 64-Bit Server VM