jive

MODULE

jive

MODULE SUMMARY

Java-Erlang Interface

DESCRIPTION

Jive is the glue which allows Java Applets/Applications to interact with Erlang.

Java and Erlang has Jive packages which hide the socket communication from the programmer. The Java side also contains a number of wrapper classes for each Erlang variable type (see the Java Jive API).

Java Applets/Applications can interact with Erlang and:

• spawn new Erlang processes
  
• send messages to Erlang processes
  
• do Erlang apply on functions.
  

Erlang processes can also send messages to Java objects.

EXPORTS

start()
start(Port) -> pid()

Types:
Port = int()

start starts the Jive server, listening to Port. The default port for start/0 is 14000.

stop() -> shutdown

stop/0 stops the Jive server.

allow(all)
allow({Module,Function,Arity}) -> ServerRet

Types:
Module = Function = atom()
Arity = int()
ServerRet = all | {allow,{Module,Function,Arity}}

allow/1 specifies from which functions processes can be spawn, or which functions to use in apply statements.

register_pid(Pid) -> ServerRet

Types:
Pid = pid()
ServerRet = error | {pidid,int()}

register_pid/1 enables Java to send messages to a specific Erlang process. The pidid is the Java client handle to an Erlang process.

unregister_pid(Pid) -> {remove,Pid}

Types:
Pid = pid()

register_pid/1 inhibits Java from send messages to a specific Erlang process.

get_pid(PidId) -> ServerRet

Types:
PidId = int()
Pid = pid()
ServerRet = error | Pid

get_pid/1 gets the actual Pid associated with a PidId. The PidId is the Java client handle to an Erlang process.

list_to_string(List) -> {string,String}

Types:
List = String = string()

list_to_string/1 converts a list to a string. Java differentiates between lists and strings to achieve efficiency and clarity.

string_to_list({string,String}) -> List

Types:
String = List = string()

string_to_list/1 converts a string to a list. Java differentiates between lists and strings to achieve efficiency and clarity.

Configuration

It is possible to start a Jive server using the following directives in a jive config file. This is used on embedded systems.

{jive,[{args,[Port,AllowedFunctions]}]}.

      Port = int()
      AllowedFunctions = [{Module,Function,Arity}]
      Module = Function = atom()
      Arity = int()
    

The Jive server listens to Port and AllowedFunctions specifies from which functions processes can be spawn, or which functions to use in apply statements (see allow/0 above).

The following example shows a jive.config file:

[{jive,[{args,[14000,[{clock,start,2},{io,format,1}]]}]}].
    

The Jive server is started and listens to port 14000, allowing clock:start/2 and io:format/1 to be used by Java clients.

SEE ALSO

ig

AUTHORS

Kaj Nygren - kaj@medialab.ericsson.se
Joakim Grebenö - jocke@erix.ericsson.se