sergepolin/chain

Hands on Chain of responsibility

Before student enters the university, (s)he should follow 3 stages:

• go through on-line and off-line qualifying round (testing);

• send documents;

• sign the contract.

Depending on which stage the applicant is s(he) has different status. Suppose, this statues is valued in integer number status:

• status < 0 if applicant did not started the on-line tour yet

• status = 0 if aplicant passed the testing but did not sent the docs

• status > 0 if the applicant was applied and s(he) only need to sign the contract.

Declare class ApplicantStatus such that it has single field status, a constructor and a single method letting know the applicant's status

Stage pipelining

The ApplicationStage allows to build a pipeline of Innopolis University student entering:

idea to apply the docs -> testing stage -> doc collecting stage -> contract sign stage

Task

For each stage create a class with a void method process. This method should check the status of the applicant. If the applicant has corresponding to the stage status, the console should display the message. Else the applicant goes to the next by the pipeline stage. The correspondence between stage, status, and message is the following:

Stage	Status	Message
PositiveApplicationStage	> 0	"The applicant has been applied : {status}"
NegativeApplicationStage	< 0	"The applicant did not start the online test yet : {status}"
ZeroApplicationStage	= 0	"The applicant passed exams but did not send the docs : {status}"

Chain creation

To let pipeline working, Chain class arranges the pipeline stages one after another.

Task

Write fucntion buildChain such that

• ZeroApplicationStage is the next of NegativeApplicationStage;
• PositiveApplicationStage is the next of ZeroApplicationStage;
• null is the next of PositiveApplicationStage.

Null means that pipeline finished and no more stages for applicant are available.

Test your implementation