tranx is implemented using the dropwizard framework, saving a lot of boilerplate code for delivering HTTP, REST, JSON serialization, validation.

it uses gradle as its build tool and snap-ci as its continuous integration platform.

because i had to reboot my java dev environment from scratch, i developed it using "Sublime Text", with no "import" optimization...

to run the test suite:

$ gradle test

to run the webservice:

$ gradle start

then you can run the UAT curl-based scenario in another console:

$ . src/test/bash/uat.sh 

press Ctrl+C to stop the webservice...

because jackson uses java's default value when deserializing a missing property, the default parent_id of a transaction is '0' when no parent transaction is given. hence, transaction id '0' becomes a special value... for the same reason, getting a transaction with no parent id will show '0' in parent_id field:

PUT transaction/32 { "amount": 12, "type": "foo"} => { "status": "ok" }
GET transaction/32 => { "amount": 12, "type": "foo", "transaction_id": 0 }

also, the PUT transaction/$txid endpoint was interpreted as meaning "set or replace transaction with id $txid". another possibility would be to forbid replace, by using ConcurrentMap::putIfAbsent instead of Map::put in TransactionService::setTransaction.