⌛⌛ Movie data as a stream

The exercise is returned as a Maven project. Place the pom.xml file in the round8/streams directory of your local repository and create to this directory the src/main/java subdirectory. Create class files Movie.java and MovieAnalytics.java and attach them to the fi.tuni.prog3.streams package. Your files should be in the round8/streams/src/main/java/fi/tuni/prog3/streams directory. The test material is available in the corresponding directory in the remote materials repository.

This task concerns basic use of Java streams. The goal is to implement a class MovieAnalytics that offers functions for reading movie data from a file and for processing the data with Java streams. You also need to implement a simple class Movie for representing the movie data.

Implement these two classes as follows:

• The class Movie should have the following public features:

  • Constructor Movie(String title, int releaseYear, int duration, String genre, double score, String director) that initialises the object to hold the movie data provided by the constructor parameters: title, release year, duration, genre, rating score and director.

  • Getter functions for all data of the movie: getTitle(), getReleaseYear(), and so on.

• The class MovieAnalytics should have the following public features:

  • Constructor MovieAnalytics() that initialises an empty container for the movies. For example, a list containing Movie elements will suffice for this task.

  • Static member function Consumer<Movie> showInfo() that returns an object that implements the interface Consumer<Movie> and whose function accept(Movie t) prints out information of the movie t in a single line of the form "title (By director, releaseYear)". The line ends into a new line. See the example output files for details. Please, note that it is enough to return a lambda that implements the Consumer interface. For example, return p -> System.out.println(...);, where ... is intentionally censored part of the statement.

  • Member function void populateWithData(String fileName) that reads movie data from the file spedicifed by the parameter.

    • The file is expected to contain lines of the form "title;releaseYear;duration;genre;score;director". That is, each line describes one movie and includes the same set of information that is passed via parameters to the constructor of the Movie class.

      • Straight-forward line splitting by semicolons with the split function of the String class will work fine here. You just need to convert some parts into suitable numbers.

  • Member function Stream<Movie> moviesAfter(int year) that returns a stream that lists all movies released in the year year or later.

  • Member function Stream<Movie> moviesBefore(int year) that returns a stream that lists all movies released in the year year or earlier.

  • Member function Stream<Movie> moviesBetween(int yearA, int yearB) that returns a stream that lists all movies released between the years yearA and yearB, including yearA and yearB.

  • Member function Stream<Movie> moviesByDirector(String director) that returns a stream that lists all movies directed by director.

The last four functions must return a stream that lists the movies in ascending order of release year. Movies with the same release year are ordered by title using the default order of the String objects.

A note about returning a stream: Return a stream that has been set to perform intermediate, but no terminal operations. For example, a stream that lists the unique items of the array int[] ia = [1, 2, 5, 4, 2, 5, 4] in sorted order could be created and returned as return Arrays.stream(ia).distinct().sorted();. The recipient of this stream could then read the values 1, 2, 4 and 5 from the stream.

The automatic tests, and the ones given below, assume that you make the following definitions in your pom.xml project file:

• The value of artifactId is streams.

• The value of version is 1.0.

• The values of the maven.compiler.source and maven.compiler.target elements are 17 or lower. The grader uses Java 17, so any newer versions won’t work.

• A Onejar plugin definition where the value of mainClass is MovieTest which is the name of the given test class (see below).

Testing

You may test your implementation by using the test program given in the file MovieTest.java, the movie data files input1.txt, input1.txt and input1.txt and the example outputs given in the files output1.txt, output2.txt and output3.txt.

Place MovieTest.java into the root of the src/main/java subdirectory of your Maven project, and the other files into the root directory of your Maven project, that is, where the pom.xml is. Note that MovieTest.java does not include a package definition and therefore is not placed into a deeper subdirectory.

After this you can compile the program with mvn package and run the tests as java -jar target/streams-1.0.one-jar.jar input1.txt, java -jar target/streams-1.0.one-jar.jar input2.txt and java -jar target/streams-1.0.one-jar.jar input3.txt in the root directory of the project. The expected outputs of these tests are given in the files output1.txt, output2.txt and output3.txt.

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