Method newStrongInterner

output/java_guava/1.4.17/Interners.java:45–54

Returns a new thread-safe interner which retains a strong reference to each instance it has interned, thus preventing these instances from being garbage-collected. If this retention is acceptable, this implementation may perform better than #newWeakInterner.

()

  public static <E> Interner<E> newStrongInterner() {
    final ConcurrentMap<E, E> map = new MapMaker().makeMap();
    return new Interner<E>() {
      @Override
      public E intern(E sample) {
        E canonical = map.putIfAbsent(checkNotNull(sample), sample);
        return (canonical == null) ? sample : canonical;
      }
    };
  }

  /**
   * Returns a new thread-safe interner which retains a weak reference to each instance it has