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Thread: Design a class that acts as a library for the following kinds of media: book, video, and newspaper

  1. #1
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    Default Design a class that acts as a library for the following kinds of media: book, video, and newspaper

    import java.util.ArrayList;

    /*
    * example of using Generics
    */

    public class Library<T> {

    private ArrayList<T> mediaCollection = new ArrayList<T>();

    public Library() {
    Book b = new Book();
    storeMedia(b);
    Video v = new Video();
    storeMedia(v);
    Newspaper n = new Newspaper();
    storeMedia(n);
    showMedia();
    }

    public void showMedia() {
    System.out.println("These items are in the media collection:");
    for (Object resource : mediaCollection.toArray()) {
    System.out.print("\t" + resource.toString() + "\n");
    }
    }

    public void storeMedia(T item) {
    mediaCollection.add(item);
    }

    public class Book implements Media {

    String type = "book";
    String name = "Robinson Curuso";

    public Book(){
    System.out.println(this.getClass());
    }

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    class Video implements Media {

    String type = "video";
    String name = "Elvis Pressley in the Army";

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    class Newspaper {

    String type = "newspaper";
    String name = "News & Disturber";

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    interface Media {
    // String type;
    }

    public static void main(String[] args) {
    Library<Media> lib = new Library<Media>();
    }

    }

    --- Update ---

    Current error is on line 13 the "storeMedia(b);" and other two similar lines. Error message, "method storeMedia in class Library<T> cannot be applied to given types, required T, found Library<T>.Book.

    I have made many attempts trying to get clean compile. I think I am missing a basic concept so an explanation along with the code remedy would be appreciated. Thanks in advance


    Quote Originally Posted by vbala2k5 View Post
    import java.util.ArrayList;

    /*
    * example of using Generics
    */

    public class Library<T> {

    private ArrayList<T> mediaCollection = new ArrayList<T>();

    public Library() {
    Book b = new Book();
    storeMedia(b);
    Video v = new Video();
    storeMedia(v);
    Newspaper n = new Newspaper();
    storeMedia(n);
    showMedia();
    }

    public void showMedia() {
    System.out.println("These items are in the media collection:");
    for (Object resource : mediaCollection.toArray()) {
    System.out.print("\t" + resource.toString() + "\n");
    }
    }

    public void storeMedia(T item) {
    mediaCollection.add(item);
    }

    public class Book implements Media {

    String type = "book";
    String name = "Robinson Curuso";

    public Book(){
    System.out.println(this.getClass());
    }

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    class Video implements Media {

    String type = "video";
    String name = "Elvis Pressley in the Army";

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    class Newspaper {

    String type = "newspaper";
    String name = "News & Disturber";

    public String toString() {
    return "type is " + type + ", name is: " + name;
    }
    }

    interface Media {
    // String type;
    }

    public static void main(String[] args) {
    Library<Media> lib = new Library<Media>();
    }

    }

  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Design a class that acts as a library for the following kinds of media: book, video, and newspaper

    Current error is on line 13
    Which line is line 13? The posted code does not have line numbers. Add a comment on line 13 to make it easy to find.

    Please copy the full text of the error messages and paste it here. You have only posted a few lines.

    The storeMedia method takes a type T. The code is not passing a correct type to the method.

    Please edit your post and wrap your code with code tags:

    [code]
    **YOUR CODE GOES HERE**
    [/code]

    to get highlighting and preserve formatting.
    If you don't understand my answer, don't ignore it, ask a question.

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