Clojure

A small bank application with Clojure

Overview

Clojure is a passionate language that uses strong mathematical expressions for you to write a code, I think it’s cool. I am not a language expert, in fact in any language, I have a general profile, I decided to create a small banking application for study and testing purposes.

Tools

Dexter’s labs:

bank application

I’ve used clojure with Leiningen and use the Emacs editor that perfectly matches with Clojure. For more information check here:

  • https://www.braveclojure.com/basic-emacs/

1. Project Design

The idea of the small bank is to create a Rest API using Clojure, where the user can do:

  • Create a new account if there is no.
  • The user can put money into this account.
  • The user can withdraw money from the account.
  • The multi-threaded system controls the concurrency of multiple concurrent accesses.
  • The operation is using a Rest Api.
  • Check account balance.

1.1 Start

I did tests on the FreeBSD / Mac OS and Ubuntu operating systems you can download the project:

1
git clone https://github.com/edersoncorbari/small-bank.git

Now you need to raise the HTTP server.

1
./launch-app

By default the server uses port 3000. On another terminal run the curl response test:

1
./launch-curl

You should get the following outputs in response:

001
002
003
004
005
006
007
008
009
010
011
012
013
014
015
016
017
018
019
020
021
022
023
024
025
026
027
028
029
030
031
032
033
034
035
036
037
038
039
040
041
042
043
044
045
046
047
048
049
050
051
052
053
054
055
056
057
058
059
060
061
062
063
064
065
066
067
068
069
070
071
072
073
074
075
076
077
078
079
080
081
082
083
084
085
086
087
088
089
090
091
092
093
094
095
096
097
098
099
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
-------------------------------------------------------------------------------------
*** Simple Rest API to Check/Balance Small-Bank ***
 
Please use the (curl-api-test) script for testing.
-------------------------------------------------------------------------------------
Add money account: 1 -> Crediting: 316.22776601683793319988
:> Successful transaction
Add money account: 2 -> Crediting: 447.21359549995793928183
:> Successful transaction
Add money account: 3 -> Crediting: 547.72255750516611345696
:> Successful transaction
Add money account: 4 -> Crediting: 632.45553203367586639977
:> Successful transaction
Add money account: 5 -> Crediting: 707.10678118654752440084
:> Successful transaction
Add money account: 6 -> Crediting: 774.59666924148337703585
:> Successful transaction
Add money account: 7 -> Crediting: 836.66002653407554797817
:> Successful transaction
Add money account: 8 -> Crediting: 894.42719099991587856366
:> Successful transaction
Add money account: 9 -> Crediting: 948.68329805051379959966
:> Successful transaction
Add money account: 10 -> Crediting: 1000.00000000000000000000
:> Successful transaction
Add money account: 11 -> Crediting: 1048.80884817015154699145
:> Successful transaction
Add money account: 12 -> Crediting: 1095.44511501033222691393
:> Successful transaction
Add money account: 13 -> Crediting: 1140.17542509913797913604
:> Successful transaction
Add money account: 14 -> Crediting: 1183.21595661992320851346
:> Successful transaction
Add money account: 15 -> Crediting: 1224.74487139158904909864
:> Successful transaction
 
-------------------------------------------------------------------------------------
Get balance account: 1
{"account":1,"date":"2018-11-04T18:27:18.915-03:00","balance":316.22776601683796}
Get balance account: 2
{"account":2,"date":"2018-11-04T18:27:18.929-03:00","balance":447.21359549995793}
Get balance account: 3
{"account":3,"date":"2018-11-04T18:27:18.939-03:00","balance":547.7225575051662}
Get balance account: 4
{"account":4,"date":"2018-11-04T18:27:18.949-03:00","balance":632.4555320336759}
Get balance account: 5
{"account":5,"date":"2018-11-04T18:27:18.961-03:00","balance":707.1067811865476}
Get balance account: 6
{"account":6,"date":"2018-11-04T18:27:18.972-03:00","balance":774.5966692414834}
Get balance account: 7
{"account":7,"date":"2018-11-04T18:27:18.982-03:00","balance":836.6600265340755}
Get balance account: 8
{"account":8,"date":"2018-11-04T18:27:18.993-03:00","balance":894.4271909999159}
Get balance account: 9
{"account":9,"date":"2018-11-04T18:27:19.004-03:00","balance":948.6832980505138}
Get balance account: 10
{"account":10,"date":"2018-11-04T18:27:19.017-03:00","balance":1000.0}
Get balance account: 11
{"account":11,"date":"2018-11-04T18:27:19.026-03:00","balance":1048.8088481701516}
Get balance account: 12
{"account":12,"date":"2018-11-04T18:27:19.041-03:00","balance":1095.4451150103323}
Get balance account: 13
{"account":13,"date":"2018-11-04T18:27:19.056-03:00","balance":1140.175425099138}
Get balance account: 14
{"account":14,"date":"2018-11-04T18:27:19.066-03:00","balance":1183.2159566199232}
Get balance account: 15
{"account":15,"date":"2018-11-04T18:27:19.083-03:00","balance":1224.744871391589}
 
-------------------------------------------------------------------------------------
Remove money account: 1 -> Debting: 31.62277660168379331998
:> Successful transaction
Remove money account: 2 -> Debting: 44.72135954999579392818
:> Successful transaction
Remove money account: 3 -> Debting: 54.77225575051661134569
:> Successful transaction
Remove money account: 4 -> Debting: 63.24555320336758663997
:> Successful transaction
Remove money account: 5 -> Debting: 70.71067811865475244008
:> Successful transaction
Remove money account: 6 -> Debting: 77.45966692414833770358
:> Successful transaction
Remove money account: 7 -> Debting: 83.66600265340755479781
:> Successful transaction
Remove money account: 8 -> Debting: 89.44271909999158785636
:> Successful transaction
Remove money account: 9 -> Debting: 94.86832980505137995996
:> Successful transaction
Remove money account: 10 -> Debting: 100.00000000000000000000
:> Successful transaction
Remove money account: 11 -> Debting: 104.88088481701515469914
:> Successful transaction
Remove money account: 12 -> Debting: 109.54451150103322269139
:> Successful transaction
Remove money account: 13 -> Debting: 114.01754250991379791360
:> Successful transaction
Remove money account: 14 -> Debting: 118.32159566199232085134
:> Successful transaction
Remove money account: 15 -> Debting: 122.47448713915890490986
:> Successful transaction
 
-------------------------------------------------------------------------------------
Get balance account: 1
{"account":1,"date":"2018-11-04T18:27:19.359-03:00","balance":284.604989415154167}
Get balance account: 2
{"account":2,"date":"2018-11-04T18:27:19.372-03:00","balance":402.492235949962134}
Get balance account: 3
{"account":3,"date":"2018-11-04T18:27:19.382-03:00","balance":492.950301754649586}
Get balance account: 4
{"account":4,"date":"2018-11-04T18:27:19.394-03:00","balance":569.209978830308315}
Get balance account: 5
{"account":5,"date":"2018-11-04T18:27:19.405-03:00","balance":636.39610306789284}
Get balance account: 6
{"account":6,"date":"2018-11-04T18:27:19.416-03:00","balance":697.13700231733506}
Get balance account: 7
{"account":7,"date":"2018-11-04T18:27:19.429-03:00","balance":752.99402388066794}
Get balance account: 8
{"account":8,"date":"2018-11-04T18:27:19.440-03:00","balance":804.98447189992431}
Get balance account: 9
{"account":9,"date":"2018-11-04T18:27:19.450-03:00","balance":853.81496824546243}
Get balance account: 10
{"account":10,"date":"2018-11-04T18:27:19.463-03:00","balance":900.0}
Get balance account: 11
{"account":11,"date":"2018-11-04T18:27:19.473-03:00","balance":943.92796335313644}
Get balance account: 12
{"account":12,"date":"2018-11-04T18:27:19.483-03:00","balance":985.90060350929907}
Get balance account: 13
{"account":13,"date":"2018-11-04T18:27:19.494-03:00","balance":1026.1578825892242}
Get balance account: 14
{"account":14,"date":"2018-11-04T18:27:19.503-03:00","balance":1064.89436095793088}
Get balance account: 15
{"account":15,"date":"2018-11-04T18:27:19.513-03:00","balance":1102.27038425243009}

The above test add new accounts, then checks the balance, and then takes money out of the accounts. You can see more details of the implementation by looking at the project’s README file.

Considerations

This is project is only used for studies using clojure, developed by layman in the subject and perhaps not one of the best implementations, techniques and use of the language.

Published on Java Code Geeks with permission by Ederson Corbari, partner at our JCG program. See the original article here: A small bank application with Clojure

Opinions expressed by Java Code Geeks contributors are their own.

Ederson Corbari

Ederson is a software developer, writer and contributor to the FreeBSD community, has been working with software development for over 10 years, learned to program as a child. It has an interest in programming languages, operating systems, focus techniques and productivity.
Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

0 Comments
Inline Feedbacks
View all comments
Back to top button