Java tutorial

Stuff I forgotten

• ListIterator<E>

Dynamic Proxies

• Slide
  • with Guava

Guava

• old presentation

  • Immutable collections, instead of unmodifirable
    • ImmuatableList, Set, SortedSet, Map, (SortedMap - oneday)
    • immutable vs unmodifiable
      • immutability guarantee, easier to use, faster, less memory
    • E.g.
      • constant set using JDK (11:55)
      • a little better Collections.unmodifiableSet( new LinkedHashSet<Integer>( Arrays.asList(...)));
      • ImmutableSet LUCKY_NUMBERS = ImmutableSet.of(4,8,15...);
        • of() <- java.util.EnumSet pattern (** check it out**)
      • constant map - ImmutableMap<String, Integer> ENG_TO_INT = ImmutableMap.with("four", 4)...build() (15:16)
      • Defensive copies
        • ImmutableSet.copyOf(numbers) (17:10)
      • factories
        • ImmutableSet.of() (== Collections.emptyset ?)
        • ImmutableSet.of(a) (== Collections.singleton?)
        • ImmutableSet.of(a, b, c)
        • ImmutableSet.copyOf(someIterator);
        • ImmutableSet.copyOf(someIterable);
      • static final ImmutableMap<Integer, String> MAP = ImmutableMap.of(1, "one", 2, "two");
      • there should be a builders pattern (check current imp)
    • Don't take nulls!!!

NIO

• Five ways to max NIO and NIO2
  1. File change notification (Watch Service API)
  2. Selectors and asynchronous I/O
  3. Channels
  4. Memory mapping
  5. Character encoding and searching
• Oracle tutorial
  • Watch Service

Concurrent maps

• Usage of ConcurrentHashMap within Spring service class SO