Question

My directory structure is as follows:

/WorkingDirectory
    MyCollection.java
    /au/edu/au
        /UserInterface
            UserInterface.java
        /Collection
            Album.java
            CDAlbum.java
            DVDAlbum.java
            CollectionFactory.java

Where Album.java is an interface implemented by CDAlbum.java and DVDAlbum.java. Each .java file has the appropriate

package au.edu.uow.UserInterface;

or

package au.edu.uow.Collection;

line.

In UserInterface.java I declare an ArrayList of type Album, which gives me compile errors of

.\au\edu\uow\UserInterface\UserInterface.java:9: error: cannot find symbol
    private ArrayList<Album> myCollection;
                      ^
symbol:   class Album
location: class UserInterface

I am compiling from MyCollection.java, which has import statements for both packages.

what is causing this error? I tried adding

import au.edu.uow.Collection

to UserInterface.java, but to no avail.

Answer 1

You need either:

import au.edu.uow.Collection.*;

or:

import au.edu.uow.Collection.Album;

Using wildcard imports is more convenient but some consider this a bad practice. This is a matter of style; decide for yourself.

It is also considered good style for package names to be in all-lower-case, although this is not enforced by the compiler.