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Java Local Development Environments Exploring Your IDE Running Your Code

Brian Bartholomew
Brian Bartholomew
1,741 Points
Posted by Brian Bartholomew
Brian Bartholomew
1,741 Points

List.sort() does not exist in Java 7, what other methods could be used?

I am learning java for work. We have legacy software and use Java 7. List.sort() was introduced in Java 8. Hence, my compiling error: 

Error:(81, 10) java: cannot find symbol
  symbol:   method sort(<anonymous java.util.Comparator<com.teamtreehouse.model.Song>>)
  location: variable songs of type java.util.List<com.teamtreehouse.model.Song>

I was thinking that refactoring the List to be a Tree of some sort would help the alphabetizing.

Is there a simpler way?

2 Answers

Juan Chavez
Juan Chavez
2,995 Points
Juan Chavez
Juan Chavez
2,995 Points

I fixed this using

        List<Song> songs = byArtist().get(artistName);
        Collections.sort(songs,new Comparator<Song>() {


            @Override
            public int compare(Song song1, Song song2) {
                if (song1.equals(song2)) {
                    return 0;
                }
                return song1.mTitle.compareTo(song2.mTitle);
            }
        });

instead of

songs.sort(new Comparator<Song>() {


            @Override
            public int compare(Song song1, Song song2) {
                if (song1.equals(song2)) {
                    return 0;
                }
                return song1.mTitle.compareTo(song2.mTitle);
            }
        });
jesdavpet
jesdavpet
21,489 Points
jesdavpet
jesdavpet
21,489 Points

For earlier versions of Java I think you can use Collections in the java.util package instead.

Collections.sort( myComparableList );

http://docs.oracle.com/javase/7/docs/api/java/util/Collections.html