Java Lab 16: Collections
This lab uses Collections. Create a project named Lab16.
Problem statement: The application will let users display a list of movies in several orderings and search for specific movies by several criteria.
The tab-delimited file "movies.tsv" has information about movies, one per line. The data's format is
id#movie nameyearcountriesgenre1genre2 …
where the genre list is some number of tab-delimited strings. You'll probably want to strip the strings of spaces; some of the movie names and countries are surrounded by quotes, which should be replaced with ""; there may be multiple countries listed for a movie, but treat it as one string – we won't be looking for specific countries; and finally, for some movies, the table display's formats may not be large enough, but you can ignore that – just use the given formats.
Your program will present these choices in a menu: sort by ID, sort by name, sort by year, sort by year (reverse), search by name, search by year, search by genre, quit. The sort options will use the method sortBy(String), where the parameter is either "ID", "Name", "Year", or "Reverse Year", where the last one sorts from largest (most recent year) to smallest. The search options will use methods searchByName(String), searchByYear(int), and searchByGenre(String).
These methods return at most 5 movies. The first returns a Movie objects that match exactly on name, the second matches on year, and the third matches on genre. Each returns an ArrayList; use displayMovies() to display the results. For consistency, call sortBy("ID") before searching – otherwise, your results may differ.
To do the sorting, you need three things. First, Movie implements the interface Comparable; you'll need to implement its compareTo() method to compare movies on movieID. Second, use an anonymous inner class (recall that this is similar to an EventHandler in JavaFX) that implements Comparator; you'll need to implement its compare() method to compare movies on movieName. Third, create a class named SortByYear that also implements Comparator; you'll again need to implement its compare() method, but this time, compare movies on the year field. You should try out (not required) Eclipse's wizard: select New->Class, name it, then in the Interface box, click Add, then find Comparator and click OK, then change T to Movie and click Finish. Here's the code for sorting by year in reverse order (from the most recent year), assuming you've written the SortByYear code:
Comparator c = Collections.reverseOrder(new SortByYear());
Collections.sort(movieList, c);
Screen shots (not all output shown for long results):
Solution Design:
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Steps
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• Download
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Lab16 instructions
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Lab16Main.java, Movie.java, movies.tsv
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1. Complete all classes listed below. Check output with movies.tsv.
2. Write your name and Andrew Id at the top in all Java files to be submitted
3. Zip all the java files in a zip-file named as your Andrew ID. Submit it on Canvas.
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Class
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Member variables
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Methods
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Lab16Main
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• movieList: ArrayListe>
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main(): Creates a Lab16Main object, calls its readMovies() method with "movies.tsv"; calls getMenuChoice() in a loop; calls Lab4Main methods to do the other work. Partially coded.
public static final int
static int getMenuChoice(): display the menu, get a valid user choice. Already coded.
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void readMovies(String filename): open the movie file, read each line and split it on \t, call toMovie( ) to parse the Strings, store the new movie in movieList. Partially coded.
Movie toMovie(String[]): get the movieID (convert to int), movieName (strip it and replace "\"" with ""), year (convert to int), country (strip it and replace "\"" with ""), and the genres (split again on ",", add the genre strings to an ArrayList). New up a new Movie object from these parts and return it.
Already coded.
private void displayMovies(ArrayList): display the parameter as a table. This is parameterized so it can be used with any ArrayList argument. Already coded.
void sortBy(String): use Collections.sort() to sort the movie on the appropriate field, as indicated by the parameter (Name, ID, Year, or ReverseYear). See the code above for ReverseYear.
Partially coded.
ArrrayList searchByName(String name): returns up to
5 moves whose name match the parameter, or null if not found.
Already coded.
ArrayList searchByYear(int year): returns up to 5 movies from that year. Use displayMovies() to display what it returns.
ArrayList searchByGenre(String genre): returns up to 5 movies matching that genre. Use displayMovies() to display what it returns.
ArrayList getList(): returns movieList, breaks
encapsulation, but okay for now. Partially coded.
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Movie implements Comparable
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• int movieID:
• String movieName
• int year
• String country
• ArrayList<String> genres
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Overloaded constructor, toString(), all getters. Already coded.
int compareTo(Movie): compares this movie to the parameter on the movieID field
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SortByYear implements
Comparator
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public static int compare(Movie, Movie): compares two movies on year
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