This project is a implementation of the org.camunda.bpm.engine.delegate.JavaDelegate interface for Camunda version 7.16.0. It allows Camunda service tasks to invoke smart contracts using the SCIP protocols JSON RPC Binding. In case of a synchronous error in the reply message it throws a BPMN error event.
expected input parameters:
| Local Variable Name | Variable Assignment Type | Description | example input |
|---|---|---|---|
| timeout | String or Expression | timeout in ms or 0 for no timeout | 0 |
| inputs | List | list of input parameters in the same format as the SCIP Json RPC binding uses or empty | {"name": "amount", "type": "{"type":"integer","minimum": 0,"maximum":115792089237316195423570985008687907853269984665640564039457584007913129639935}", "value": 15 } |
| outputs | List | list of output parameters in the same format as the SCIP Json RPC binding uses or empty | { "name": "newName", "type": " {"type":"string"}"} |
| timeout | String or Expression | timeout in ms or 0 for no timeout | 0 |
| doc | String or Expression | degree of confidence as floating point number | 50.1 |
| callbackUrl | String or Expression | URL where the callback message should be send to, e.g the camunda message endpoint | http://172.16.238.14:8080/engine-rest/message |
| functionIdentifier | String or Expression | name of the smart contract function to invoke | orderPart |
| url | String or Expression | SCL of the smart contract to use | http://172.16.238.1:8081/blockchain-access-layer/webapi?blockchain=ethereum&blockchain-id=eth-0&address=0x75f17644EAEb3cC6511764a6F1138F14B3e33D0f |
The Connector will send a JSON RPC 2.0 Request to the scip gateway, with randomly generated ID and "<ProcessID>_<ActivityID>" as correlation Identifier.
Usage:
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Build the project and put the jar file to a location where camunda platform can find it (This depends on the Camunda distribution. For Camunda Platform Run this is the userlibs folder.(https://docs.camunda.org/manual/7.16/user-guide/camunda-bpm-run/#starting-with-camunda-platform-run). For the camunda docker it is the "/camunda/lib/" folder. See the camunda documentation for details.)
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The java class to use in the Task is: ScipConnector.ScipDelegate
See https://github.com/dabberpk/CaseStudy for an example where this delegate is used.