--- title: 'Thema der Woche: Collection-API' url: 'https://tutego.de/blog/javainsel/2008/06/thema-der-woche-collection-api' markdown: 'https://tutego.de/blog/javainsel/2008/06/thema-der-woche-collection-api.md' date: '2008-06-16' description: 'Die Collection-API enthält grundlegende Sammlungen für Listen, Kellerspeicher, Assoziativspeicher. Gehe über alle Operationen der folgenden Schnittstellen: http://java.sun.com/javase/6/docs/api/java/util/Collection.html http://java.sun.com/javase/6/docs/api/java/util/List.html http://java.sun.com/…' taxonomy: category: - 'Die wöchentliche Dosis Java' --- # Thema der Woche: Collection-API ![Illustration einer tropischen Insel mit Palmen und einem hohen Berg](https://tutego.de/blog/javainsel/user/themes/tutego/images/insel-cover.jpg)# Java Blog für Programmierer [Java Blog für Programmierer](https://tutego.de/blog/javainsel/) ## Thema der Woche: Collection-API 16.06.2008 · [Christian Ullenboom](https://tutego.de/blog/javainsel/author/admin/) Die `Collection`-API enthält grundlegende Sammlungen für Listen, Kellerspeicher, Assoziativspeicher. Gehe über alle Operationen der folgenden Schnittstellen: - [http://java.sun.com/javase/6/docs/api/java/util/Collection.html](http://java.sun.com/javase/6/docs/api/java/util/Collection.html "http://java.sun.com/javase/6/docs/api/java/util/Collection.html") - [http://java.sun.com/javase/6/docs/api/java/util/List.html](http://java.sun.com/javase/6/docs/api/java/util/List.html "http://java.sun.com/javase/6/docs/api/java/util/List.html") - [http://java.sun.com/javase/6/docs/api/java/util/Queue.html](http://java.sun.com/javase/6/docs/api/java/util/Queue.html "http://java.sun.com/javase/6/docs/api/java/util/Queue.html") - [http://java.sun.com/javase/6/docs/api/java/util/Set.html](http://java.sun.com/javase/6/docs/api/java/util/Set.html "http://java.sun.com/javase/6/docs/api/java/util/Set.html") - [http://java.sun.com/javase/6/docs/api/java/util/Map.html](http://java.sun.com/javase/6/docs/api/java/util/Map.html "http://java.sun.com/javase/6/docs/api/java/util/Map.html") Finde je ein Beispiel für `keySet()`, `retainAll()`, `toArray()`, `headSet()`. Welche Implementierungseigenschaften haben die folgenden Klassen: - [http://java.sun.com/javase/6/docs/api/java/util/HashSet.html](http://java.sun.com/javase/6/docs/api/java/util/HashSet.html "http://java.sun.com/javase/6/docs/api/java/util/HashSet.html") - [http://java.sun.com/javase/6/docs/api/java/util/TreeSet.html](http://java.sun.com/javase/6/docs/api/java/util/TreeSet.html "http://java.sun.com/javase/6/docs/api/java/util/TreeSet.html") - [http://java.sun.com/javase/6/docs/api/java/util/ArrayList.html](http://java.sun.com/javase/6/docs/api/java/util/ArrayList.html "http://java.sun.com/javase/6/docs/api/java/util/ArrayList.html") - [http://java.sun.com/javase/6/docs/api/java/util/LinkedList.html](http://java.sun.com/javase/6/docs/api/java/util/LinkedList.html "http://java.sun.com/javase/6/docs/api/java/util/LinkedList.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/PriorityBlockingQueue.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/PriorityBlockingQueue.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/PriorityBlockingQueue.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentLinkedQueue.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArraySet.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArraySet.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArraySet.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArrayList.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArrayList.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArrayList.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentSkipListSet.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentSkipListSet.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentSkipListSet.html") - [http://java.sun.com/javase/6/docs/api/java/util/EnumMap.html](http://java.sun.com/javase/6/docs/api/java/util/EnumMap.html "http://java.sun.com/javase/6/docs/api/java/util/EnumMap.html") - [http://java.sun.com/javase/6/docs/api/java/util/HashMap.html](http://java.sun.com/javase/6/docs/api/java/util/HashMap.html "http://java.sun.com/javase/6/docs/api/java/util/HashMap.html") - [http://java.sun.com/javase/6/docs/api/java/util/IdentityHashMap.html](http://java.sun.com/javase/6/docs/api/java/util/IdentityHashMap.html "http://java.sun.com/javase/6/docs/api/java/util/IdentityHashMap.html") - [http://java.sun.com/javase/6/docs/api/java/util/LinkedHashMap.html](http://java.sun.com/javase/6/docs/api/java/util/LinkedHashMap.html "http://java.sun.com/javase/6/docs/api/java/util/LinkedHashMap.html") - [http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentHashMap.html](http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentHashMap.html "http://java.sun.com/javase/6/docs/api/java/util/concurrent/ConcurrentHashMap.html") - [http://java.sun.com/javase/6/docs/api/java/util/WeakHashMap.html](http://java.sun.com/javase/6/docs/api/java/util/WeakHashMap.html "http://java.sun.com/javase/6/docs/api/java/util/WeakHashMap.html") Fülle eine WeakHashMap mit sovielen neuen `java.awt.Point`-Objekten, bis es einen `OutOfMemoryError` gibt. Fange diesen ab und gib die Größe der WeakHashMap aus. Laufe zum Verständnis der Implementierung folgende Szenerien im Debugger ab: - Ein Element wird in die `HashMap` eingefügt, dann erfragt. - In eine `LinkedList` bzw. `ArrayList` werden einige Elemente eingefügt, dann nach ihrer Position erfragt und gelöscht. Kategorien: [Die wöchentliche Dosis Java](https://tutego.de/blog/javainsel/category/die-woechentliche-dosis-java/) [← Alle Beiträge](https://tutego.de/blog/javainsel/) --- ## Navigation - Previous: [Buchkritik: Hardcore Java](https://tutego.de/blog/javainsel/2008/06/buchkritik-hardcore-java.md) - Next: [Open Source Docking Frameworks](https://tutego.de/blog/javainsel/2008/06/open-source-docking-frameworks.md)