war/src/main/java/net/wpitchoune/pnews/ArticleStore.java

   1 package net.wpitchoune.pnews;
   2
   3 import java.lang.ref.WeakReference;
   4 import java.util.ArrayList;
   5 import java.util.HashMap;
   6 import java.util.logging.Logger;
   7
   8 public class ArticleStore {
   9         public final static ArticleStore singleton = new ArticleStore();
  10         private final HashMap<String, WeakReference<Article>> articles = new HashMap<>();
  11         private final static Logger LOG = Logger.getLogger(ArticleStore.class.getName());
  12
  13         public Article get(String link) {
  14                 WeakReference<Article> ref;
  15                 Article result;
  16
  17                 synchronized (articles) {
  18                         ref = articles.get(link);
  19                         if (ref == null) {
  20                                 return null;
  21                         }
  22
  23                         result = ref.get();
  24                         if (result == null) {
  25                                 LOG.info("Article has been released from memory: " + link);
  26                                 articles.remove(link);
  27                         }
  28
  29                         return result;
  30                 }
  31         }
  32
  33         public Article getArticle(String link, ArticleFactory factory) {
  34                 Article result;
  35
  36                 synchronized (articles) {
  37                         result = get(link);
  38                         if (result == null) {
  39                                 result = factory.create();
  40                                 articles.put(link, new WeakReference<>(result));
  41                                 LOG.fine("Article has been added: " + result.getLink());
  42                         }
  43
  44                         return result;
  45                 }
  46         }
  47
  48         public long size() {
  49                 synchronized (this) {
  50                         return articles.size();
  51                 }
  52         }
  53
  54         public Article[] getArticles() {
  55                 ArrayList<Article> result;
  56                 Article a;
  57
  58                 synchronized (articles) {
  59                         result = new ArrayList<>(articles.size());
  60
  61                         for (WeakReference<Article> r: articles.values()) {
  62                                 a = r.get();
  63                                 if (a != null)
  64                                         result.add(a);
  65                         }
  66
  67                         return result.toArray(new Article[] {});
  68                 }
  69         }
  70 }