I have really enjoyed working on this challenge. This exercise allowed me to demonstrate my understanding of object oriented design and put me outside of my comfort zone as I haven't created anything like this before using Java.
In solving this challenge and producing the code in this repository I sifted pages after pages of StackOverflow questions, blogs and articles. I have included below examples of few of these useful articles.
I set out with the aim that I was going to test drive the development of this feature. However I found myself fairly confused as most things I tried were new to me and it was more the case of complete the project and add unit test once you have a better understanding of Java.
I have tried to test the main methods and use stubbing and mocks using Mockito. I feel that some of the tests were unnecessary, such as the getter methods. But I couldn't really make up my mind if it was useful or not!
I suppose every project does build up a level of technical debt usually time being the main factor. Ensuring that I kept an eye on progress and improvements to this feature I used the github issues tab.
You will find that I have left some open to revisit in the future. I would say namely the parts which need refactoring and enhancing are around the mocking and stubbing out of some classes in my unit tests.
The aim of this application is to take in two sources of data that contain information which correlate with the defined models Investor and Loan.
In designing this app I have considered the object oriented developments main principals as per below:
Using private methods and variables where necessary to hide the internal workings of a class. This is more obviously mainly demonstrated in the getter and setter methods
I have used interfaces to create a blue print to dictate the behaviors that are expected in certain classes. However implementation of those methods were specific to the type of Object I was dealing with. Example of this is demonstrated in the DAO directory. I have a specific implementation for my Investor Object and Loan Object being created using a CSV.
However, if this data source does change in the future as long as the implementation returns the type of data I expect my code shouldn't break.
Although I haven't specifically used inheritance in this project. I have identified an aread that I could've demonstrated this principal.
In my model directory my FundedLoan class could've inherited from both Investor and Loan.
Creating overloaded constructors although I appreciate this principal is more closely associated with overloaded methods.
• Is the term calculated in years or months? Answer: months
• I found this stackoverflow ARTICLE interesting as I was not sure what are the advantages or using either a setter or a constructor.
• Private fields + Public accessors == Encapsulation;
• This can be used as a way of creating json object
// instance method
public String toString() { //overriding the toString() method
return ("Customer name: " + getName()
+ ", SSN#: " + getSSN() ); // concatenating the name and SSN
}
• ARTICLE on using Gson for creating json from Java objects
• ARTICLE on using csv file reader without the use of annotations
• ARTICLE which helped me simplify the process of sorting object by field
• ARTICLE how to use logger in Java class
- If memory is not a problem, read using CsvToBean.parse(), which will read all beans at once and is multi-threaded. If your memory is limited, use CsvToBean.iterator() and iterate over the input. Only one bean is read at a time, making multi-threading impossible and slowing down reading, but only one object is in memory at a time (assuming you process and release the object for the garbage collector immediately).
Context ABC is in the peer-to-peer business. As part of this, when a borrower applies for a mortgage and ABC provides an offer, ABC needs to be able to guarantee that we have enough investment from our investors to fund the borrowers mortgage. In order to do this, we allow our lenders to request investments.
• investments.csv. In this file, you will find a number of requests that investors have made. For example, line 1 means "Alice wants to invest £100 for up to 12 months in the FIXED product". Each line represents a separate request that was placed on the ABC platform.
• loans.csv. In this file, you will find a number of loans that ABC would like to find funds for. Initially no loan has any investment against it. The amount field simply shows the amount the borrower wishes to borrow. We must match every penny on this amount with investor funds.
Please write a program that will match the investments to the loans following the business rules listed below.
• The program should be written in Java.
• Once the program has run, the program must output the loans that are fully funded
• the names of the people funding the loans and the amount of money they have invested in the loan.
• A valid "funded" loan must be fully funded from the investments.csv file. If a loan does not have all the funds necessary, then it cannot qualify.
• Partially funded loans are of no value to ABC (we can't give our borrowers less money than they need to buy the property)
• Over-funded loans are also not useful (we can't give our borrowers more money than they want as this means they will have to eventually pay more interest).
• If someone wants to invest in TRACKER, you can't place their money into a Loan that is FIXED - and vice-versa.
• Loans should be processed in the order of their completed date (oldest to newest)
• The term of the investment must be greater than the term of the loan (i.e. the investor needs to be willing to put money in for longer than the loan needs it for).
• Produce a JSON representation (using some library) of the result when you print it out