This module implements the JSON-RPC based protocol for inter-process communication (IPC) with openLCA.

On the openLCA side, an IPC server is started which accepts function calls and returns results. Function calls and results are encoded in JSON-RPC where a function just has a method name and optional parameters and returns a result or error. The function calls and return values are just plain JSON objects send over a transport protocol. Currently, the openLCA IPC server uses HTTP and accepts POST requests for method calls. Thus, you could even use curl to call functions:

curl -X POST https://localhost:8080 -d @file.json -H "Content-Type: application/json"

For Parameters and results the types as defined in the olca-schema format are used. This is the same format that is used for the Linked Data export and import in openLCA. However, not everything that is defined in the olca-schema format can be imported or exported (like calculation setups for example).

Using the IPC server via the API looks like this:

Server server = new Server(8080);
server.withDefaultHandlers(aDatabase, aMatrixSolver);
server.start();

This will start the server at port 8080 with the default protocol (see below). However, it is also possible to configure the server protocol by registering specific method handlers (instead of calling withDefaultHandlers):

server.register(aHandler1);
server.register(aHandler2);
// ...

A handler is a plain object of which methods are registered to handle method calls if they fulfill the following requirements:

• they are declared as public and annotated with the @Rpc annotation providing a unique method name
• they take a single parameter of type RpcRequest
• they return a result of type RpcResponse

For example, an instance of the following class could be used as handler:

public class MyHandler {

  @Rpc("my/method")
  public RpcResponse myMethod(RpcRequest req) {
    return Responses.of("Works!", req);
  }
}