Java Language Comparer les opérations avec les collections - Créer des collections


Exemple

Comparer les opérations avec les collections - Créer des collections

1. Créer une liste
La description JDK goyave gs-collections
Créer une liste vide new ArrayList<> () Lists.newArrayList() FastList.newList()
Créer une liste à partir de valeurs Arrays.asList("1", "2", "3") Lists.newArrayList("1", "2", "3") FastList.newListWith("1", "2", "3")
Créer une liste avec une capacité = 100 new ArrayList<>(100) Lists.newArrayListWithCapacity(100) FastList.newList(100)
Créer une liste à partir de n'importe quelle collection new ArrayList<>(collection) Lists.newArrayList(collection) FastList.newList(collection)
Créer une liste à partir de tout Iterable - Lists.newArrayList(iterable) FastList.newList(iterable)
Créer une liste depuis Iterator - Lists.newArrayList(iterator) -
Créer une liste à partir d'un tableau Arrays.asList(array) Lists.newArrayList(array) FastList.newListWith(array)
Créer une liste en utilisant l'usine - - FastList.newWithNValues(10, () -> "1")

Exemples:

    System.out.println("createArrayList start");
    // Create empty list
    List<String> emptyGuava = Lists.newArrayList(); // using guava
    List<String> emptyJDK = new ArrayList<>(); // using JDK
    MutableList<String>  emptyGS = FastList.newList(); // using gs

    // Create list with 100 element
    List < String > exactly100 = Lists.newArrayListWithCapacity(100); // using guava
    List<String> exactly100JDK = new ArrayList<>(100); // using JDK
    MutableList<String>  empty100GS = FastList.newList(100); // using gs

    // Create list with about 100 element
    List<String> approx100 = Lists.newArrayListWithExpectedSize(100); // using guava
    List<String> approx100JDK = new ArrayList<>(115); // using JDK
    MutableList<String>  approx100GS = FastList.newList(115); // using gs

    // Create list with some elements
    List<String> withElements = Lists.newArrayList("alpha", "beta", "gamma"); // using guava
    List<String> withElementsJDK = Arrays.asList("alpha", "beta", "gamma"); // using JDK
    MutableList<String>  withElementsGS = FastList.newListWith("alpha", "beta", "gamma"); // using gs

    System.out.println(withElements);
    System.out.println(withElementsJDK);
    System.out.println(withElementsGS);

    // Create list from any Iterable interface (any collection)
    Collection<String> collection = new HashSet<>(3);
    collection.add("1");
    collection.add("2");
    collection.add("3");

    List<String> fromIterable = Lists.newArrayList(collection); // using guava
    List<String> fromIterableJDK = new ArrayList<>(collection); // using JDK
    MutableList<String>  fromIterableGS = FastList.newList(collection); // using gs

    System.out.println(fromIterable);
    System.out.println(fromIterableJDK);
    System.out.println(fromIterableGS);
    /* Attention: JDK create list only from Collection, but guava and gs can create list from Iterable and Collection */

    // Create list from any Iterator
    Iterator<String> iterator = collection.iterator();
    List<String> fromIterator = Lists.newArrayList(iterator); // using guava
    System.out.println(fromIterator);

    // Create list from any array
    String[] array = {"4", "5", "6"};
    List<String> fromArray = Lists.newArrayList(array); // using guava
    List<String> fromArrayJDK = Arrays.asList(array); // using JDK
    MutableList<String>  fromArrayGS = FastList.newListWith(array); // using gs
    System.out.println(fromArray);
    System.out.println(fromArrayJDK);
    System.out.println(fromArrayGS);

    // Create list using fabric
    MutableList<String>  fromFabricGS = FastList.newWithNValues(10, () -> String.valueOf(Math.random())); // using gs
    System.out.println(fromFabricGS);

    System.out.println("createArrayList end");
2 Créer un ensemble
La description JDK goyave gs-collections
Créer un ensemble vide new HashSet<>() Sets.newHashSet() UnifiedSet.newSet()
Créatrice définie à partir de valeurs new HashSet<>(Arrays.asList("alpha", "beta", "gamma") ) Sets.newHashSet("alpha", "beta", "gamma") UnifiedSet.newSetWith("alpha", "beta", "gamma")
Créer un ensemble à partir de n'importe quelle collection new HashSet<>(collection) Sets.newHashSet(collection) UnifiedSet.newSet(collection)
Créer un ensemble à partir de n'importe quelle Iterable - Sets.newHashSet(iterable) UnifiedSet.newSet(iterable)
Créer un ensemble à partir de n'importe quel itérateur - Sets.newHashSet(iterator) -
Créer un ensemble depuis Array new HashSet<>(Arrays.asList(array)) Sets.newHashSet(array) UnifiedSet.newSetWith(array)

Exemples:

    System.out.println("createHashSet start");
    // Create empty set
    Set<String> emptyGuava = Sets.newHashSet(); // using guava
    Set<String> emptyJDK = new HashSet<>(); // using JDK
    Set<String> emptyGS = UnifiedSet.newSet(); // using gs

    // Create set with 100 element
    Set<String> approx100 = Sets.newHashSetWithExpectedSize(100); // using guava
    Set<String> approx100JDK = new HashSet<>(130); // using JDK
    Set<String> approx100GS = UnifiedSet.newSet(130); // using gs

    // Create set from some elements
    Set<String> withElements =  Sets.newHashSet("alpha", "beta", "gamma"); // using guava
    Set<String> withElementsJDK = new HashSet<>(Arrays.asList("alpha", "beta", "gamma")); // using JDK
    Set<String> withElementsGS  = UnifiedSet.newSetWith("alpha", "beta", "gamma"); // using gs

    System.out.println(withElements);
    System.out.println(withElementsJDK);
    System.out.println(withElementsGS);

    // Create set from any Iterable interface (any collection)
    Collection<String> collection = new ArrayList<>(3);
    collection.add("1");
    collection.add("2");
    collection.add("3");

    Set<String> fromIterable = Sets.newHashSet(collection); // using guava
    Set<String> fromIterableJDK = new HashSet<>(collection); // using JDK
    Set<String> fromIterableGS  = UnifiedSet.newSet(collection); // using gs

    System.out.println(fromIterable);
    System.out.println(fromIterableJDK);
    System.out.println(fromIterableGS);
    /* Attention: JDK create set only from Collection, but guava and gs can create set from Iterable and Collection */

    // Create set from any Iterator
    Iterator<String> iterator = collection.iterator();
    Set<String> fromIterator = Sets.newHashSet(iterator); // using guava
    System.out.println(fromIterator);

    // Create set from any array
    String[] array = {"4", "5", "6"};
    Set<String> fromArray = Sets.newHashSet(array); // using guava
    Set<String> fromArrayJDK = new HashSet<>(Arrays.asList(array)); // using JDK
    Set<String> fromArrayGS  = UnifiedSet.newSetWith(array); // using gs
    System.out.println(fromArray);
    System.out.println(fromArrayJDK);
    System.out.println(fromArrayGS);

    System.out.println("createHashSet end");
3 Créer une carte
La description JDK goyave gs-collections
Créer une carte vide new HashMap<>() Maps.newHashMap() UnifiedMap.newMap()
Créer une carte avec une capacité = 130 new HashMap<>(130) Maps.newHashMapWithExpectedSize(100) UnifiedMap.newMap(130)
Créer une carte à partir d'une autre carte new HashMap<>(map) Maps.newHashMap(map) UnifiedMap.newMap(map)
Créer une carte à partir des clés - - UnifiedMap.newWithKeysValues("1", "a", "2", "b")

Exemples:

    System.out.println("createHashMap start");
    // Create empty map
    Map<String, String> emptyGuava = Maps.newHashMap(); // using guava
    Map<String, String> emptyJDK = new HashMap<>(); // using JDK
    Map<String, String> emptyGS = UnifiedMap.newMap(); // using gs

    // Create map with about 100 element
    Map<String, String> approx100 = Maps.newHashMapWithExpectedSize(100); // using guava
    Map<String, String> approx100JDK = new HashMap<>(130); // using JDK
    Map<String, String> approx100GS = UnifiedMap.newMap(130); // using gs

    // Create map from another map
    Map<String, String> map = new HashMap<>(3);
    map.put("k1","v1");
    map.put("k2","v2");
    Map<String, String> withMap =  Maps.newHashMap(map); // using guava
    Map<String, String> withMapJDK = new HashMap<>(map); // using JDK
    Map<String, String> withMapGS = UnifiedMap.newMap(map); // using gs

    System.out.println(withMap);
    System.out.println(withMapJDK);
    System.out.println(withMapGS);

    // Create map from keys
    Map<String, String> withKeys =  UnifiedMap.newWithKeysValues("1", "a", "2", "b");
    System.out.println(withKeys);

    System.out.println("createHashMap end");

Plus d'exemples: CreateCollectionTest

  1. CollectionCompare
  2. CollectionSearch
  3. JavaTransform