arrays - Java, singleton elements modification, software patterns -

short question. gets answered pretty fast. lets have singleton this:

package main.library;  public enum librarysingleton {     instance(new string[][]{});      final string[][] bookstore;      private librarysingleton(string[][] bookstore){         this.bookstore = bookstore;     } } 

and book class holds 3 variables:

package main.library;  public class book{     string author;     string title;     int pages;      @override public string tostring(){         return ("|" + author + "|" + title + "|" + pages + "|");     }      public book(){         system.out.println("error: no book information specified");     }      public book(string author, string title, int pages){         this.author = author;         this.title = title;         this.pages = pages;     }      public string getauthor(){         return author;     }      public string gettitle(){         return title;     }      public int getpages(){         return pages;     } } 

i'm looking on how use singleton array holding books. how can access books, throw them array (singleton), or remove them array (singleton)? in case singleton should written differently, please correct me, , explain why wrong, i'm not "premium" java yet.

really hope guys going answer me on that. questions please.

if want singleton, can use following approach:

public class library {    private static final library instance = new library();    private list<book> books = new arraylist<book>();     public static library getinstance() {        return instance ;    }     public void add(book book) {         books.add(book);    } } 

of course, add synchronization if program has multiple threads. , if program runs in j2ee environment, complex classloading occurs, need different pattern.