IBAN Validator

Java program wit API and Command Line Interface for IBAN validation.

About the program

One of technical tasks I got while looking for my first software developer position. Made using Java 11, Jetty, Servlet, commons-validator and Maven.

Program validates IBAN by entering it into terminal or from given file, result saved in *.out file;
Can be run as standalone WEB service for IBAN validation through API endpoint: http://host:port/api/ibanvalidator?iban=CODEtoValidate;
Program uses commons-validator library to validate IBANs.

Made a decent effort to write clean OOP code to my Date.now() best understanding, like separation of concerns and encapsulation of internal workings of the class to hide details from outside while providing a simple interface to work with a class and there should be no to little pain adding new functionality.

How to set up the program

Open terminal and use git clone command to download the remote GitHub repository to your computer:

git clone https://github.com/skarware/technical-task-ibanvalidator.git

It will create a new folder with same name as GitHub repository technical-task-ibanvalidator. All the project files and git data will be cloned into it. After cloning complete change directories into that new folder:

cd technical-task-ibanvalidator

To compile the application into executable JAR run this command (uses maven wrapper):

./mvnw clean package

Or using your installed maven version:

mvn clean package

How to use

To run the program use java JRE with executable JAR file with no arguments or with one or two arguments: one for 'api' if run as standalone WEB service, second for its port. See below for more:

java -jar target/ibanvalidator-1.0-SNAPSHOT-jar-with-dependencies.jar

If all went well you should see interactive User Interface printed to STDOUT:

skarware@citadel:~technical-task-ibanvalidator$ java -jar target/ibanvalidator-1.0-SNAPSHOT-jar-with-dependencies.jar
----------------------------------------------------------------------------
A - Check IBAN validity from terminal input
B - Check IBAN validity in given text file
C - Start IBAN validation API on port 8080
E - Exit Program
----------------------------------------------------------------------------
Enter your option:

If option A chosen, enter single IBAN into a terminal window, program will print the result into STDOUT:

Your option: A
Please enter IBAN: LT647044001231465456
'LT647044001231465456' is Valid IBAN;

Your option: A
Please enter IBAN: LT227044077788877777
'LT227044077788877777' is Not valid IBAN;

If option B chosen and IBAN input file provided, in example IBANList.txt, program will parse the file, print the result to STDOUT and Saves it into other file named: IBANList.txt.out:

Your option: B
Please provide File path: IBANList.txt
Reading IBAN codes from a FILE...       data successfully loaded.
AA051245445454552117989,false
LT647044001231465456,true
LT517044077788877777,true
LT227044077788877777,false
CC051245445454552117989,false
Writing IBAN codes into a FILE...       successfully written to a FILE.

If option C chosen then program will start Http Server on port 8080 and return to Main Menu. To stop the server exit program with Main Menu option E:

Your option: C
2020-07-16 01:07:41.640:INFO::main: Logging initialized @32136ms to org.eclipse.jetty.util.log.StdErrLog
2020-07-16 01:07:41.707:INFO:oejs.Server:main: jetty-9.4.30.v20200611; built: 2020-06-11T12:34:51.929Z; git: 271836e4c1f4612f12b7bb13ef5a92a927634b0d; jvm 11.0.7+10-post-Ubuntu-2ubuntu218.04
2020-07-16 01:07:41.769:INFO:oejs.AbstractConnector:main: Started ServerConnector@13b6d03{HTTP/1.1, (http/1.1)}{0.0.0.0:8080}
2020-07-16 01:07:41.771:INFO:oejs.Server:main: Started @32268ms
----------------------------------------------------------------------------
A - Check IBAN validity from terminal input
B - Check IBAN validity in given text file
C - Start IBAN validation API on port 8080
E - Exit Program
----------------------------------------------------------------------------
Enter your option: e
Your option: E

        Program exiting,
                         see you...
2020-07-16 01:07:52.737:INFO:oejs.AbstractConnector:main: Stopped ServerConnector@13b6d03{HTTP/1.1, (http/1.1)}{0.0.0.0:8080}

To run the program as standalone API execute JAR with one or two arguments: an 'api' argument if run as standalone WEB service with port 8080, second argument for arbitrary service port:

 java -jar target/ibanvalidator-1.0-SNAPSHOT-jar-with-dependencies.jar api

 java -jar target/ibanvalidator-1.0-SNAPSHOT-jar-with-dependencies.jar api 8090

If all went well you should see Http server INFO printed to STDOUT:

2020-07-16 01:08:19.834:INFO::main: Logging initialized @153ms to org.eclipse.jetty.util.log.StdErrLog
2020-07-16 01:08:19.897:INFO:oejs.Server:main: jetty-9.4.30.v20200611; built: 2020-06-11T12:34:51.929Z; git: 271836e4c1f4612f12b7bb13ef5a92a927634b0d; jvm 11.0.7+10-post-Ubuntu-2ubuntu218.04
2020-07-16 01:08:19.954:INFO:oejs.AbstractConnector:main: Started ServerConnector@75828a0f{HTTP/1.1, (http/1.1)}{0.0.0.0:8090}
2020-07-16 01:08:19.957:INFO:oejs.Server:main: Started @283ms

How to use API endpoint

To interacting with API one can use curl tool as in following examples:

Please note in examples below program uses default port: 8080 and runs on localhost machine.

Provide Valid IBAN:

curl --location --request GET 'http://localhost:8080/api/ibanvalidator?iban=LT647044001231465456'

Response from API: {"LT647044001231465456": "true"}

Provide Invalid IBAN:

curl --location --request GET 'http://localhost:8080/api/ibanvalidator?iban=LT227044077788877777'

Response from API: {"LT227044077788877777": "false"}

skarware / technical-task-ibanvalidator