In this assessment we will implement a general purpose application to enrich an input stream of records with an external data source. We will use three design patterns: Singleton, Factory, and Strategy
A basic requirement of implementing a general purpose application is to use configuration to pass different properties. TypeSafe config library has proven itself a powerful player in this area. It also uses a special document type called HOCON. For more information about TypeSafe config library and HOCON, see here
The assignment structure already is using the library and you don’t need to implement anything.
Download the assessment, using Eclipse import the assessment as a maven project.
- Make Configuration class singleton. The Configuration class will read your configuration file that is in this case by default reference.conf and instantiates the variables.
- Implement FileReaderParse interface for two different file types: JSON and CSV. Check out subscriber.json and subscriber.csv for the format of each line. Each line is an input to the parseSubscriber method of FileReaderParser and converts it to an instance of Subscriber.
- A Strategy pattern is implemented for InputSource class that you can inject any implementation of FileReaderParser. Complete the assessment by applying Factory pattern to instantiate a FileReaderParser based on value of "type" given in the Configuration class.