SearchByArtistPrefix.java

package student;
import java.io.*;
import java.util.*;

import student.Song.CmpArtist;

/*
 * SearchByArtistPrefix.java
 * starting code
 * Boothe 2016
 */
public class SearchByArtistPrefix {

    private Song[] songs;  // The constructor fetches and saves a reference to the song array here

    public SearchByArtistPrefix(SongCollection sc) {
        songs = sc.getAllSongs();
    }

    private ArrayList<Song> foundSongs = new ArrayList<Song>();
    ArrayList<Song> tempSongs = new ArrayList<Song>();
    /**
     * find all songs matching artist prefix
     * uses binary search
     * should operate in time log n + k (# matches)
     */
    public Song[] search(String artistPrefix) {

        // write this method

        Song tempSong = new Song(artistPrefix, "thisIsTitle", "thisIsLyrics");
        CmpArtist cmp = new CmpArtist();

        int returnValue = 0;




        while(){


            //this should return an int value either ; negative - if the element being searched for
            //is not found.. or a positive int representing at what element in the array the searched element is
            returnValue = Arrays.binarySearch(songs, tempSong, cmp);


            //if the item is not found
            if (returnValue < 0) {
                break;
            }



            //add the found song to foundSongs array
            foundSongs.add(songs[returnValue]);

            //remove the found song from original array, so not to re-copy
            songs[returnValue] = null;
        }

        //debug
        System.out.println("out of forever loop");

        songs = foundSongs.toArray(new Song[songs.length]);

        //preserve ordering
        Arrays.sort(songs);
        return songs;
    }


    public static void main(String[] args) {



        if (args.length == 0) {
            System.err.println("usage: prog songfile [search string]");
            return;
        }

        SongCollection sc = new SongCollection(args[0]);

        SearchByArtistPrefix sbap = new SearchByArtistPrefix(sc);

        if (args.length > 1){
            System.out.println("searching for: "+args[1]);
            Song[] byArtistResult = sbap.search(args[1]);

            // to do: show first 10 matches
            for (int i = 0; i <= 10; i++) {
                System.out.println("First 10 matches " + sbap.search("Be")[i].getArtist());
            }

        }
    }
}