Java Code Examples for com.google.common.collect.Iterables#frequency()

/**
 * Frequency of objects
 */
@Test
public void frequency_of_object_in_iterable () {
	
	String jingleChorus = "Oh, jingle bells, jingle bells "
			+ "Jingle all the way "
			+ "Oh, what fun it is to ride "
			+ "In a one horse open sleigh "
			+ "Jingle bells, jingle bells "
			+ "Jingle all the way "
			+ "Oh, what fun it is to ride "
			+ "In a one horse open sleigh";
	
	List<String> words = Splitter.on(CharMatcher.anyOf(" ."))
			.trimResults(CharMatcher.is('.'))
			.omitEmptyStrings()
			.splitToList(jingleChorus.toLowerCase());
	
	int numberOfOccurences = Iterables.frequency(words, "jingle");

	assertEquals(6, numberOfOccurences);
}
 

@ExpectWarning(value="GC", num=5)
public static void testIterables(Iterable<String> i, Collection<Integer> c) {
    Iterables.contains(i, 1);
    Iterables.removeAll(i, c);
    Iterables.retainAll(i, c);
    Iterables.elementsEqual(i, c);
    Iterables.frequency(i, 1);
}
 

@NoWarning("GC")
public static void testIterablesOK(Iterable<String> i, Collection<String> c) {
    Iterables.contains(i, "x");
    Iterables.removeAll(i, c);
    Iterables.retainAll(i, c);
    Iterables.elementsEqual(i, c);
    Iterables.frequency(i, "x");
}
 

private static void testCount() {
    Collection<String> collection = Lists.newArrayList("a1", "a2", "a3", "a1");
    Iterable<String> iterable = collection;
    MutableCollection<String> collectionGS = FastList.newListWith("a1", "a2", "a3", "a1");

    // Get frequency element in collection
    int i1 = Iterables.frequency(iterable, "a1"); // using guava
    int i2 = Collections.frequency(collection, "a1"); // using JDK
    int i3 = CollectionUtils.cardinality("a1", iterable); // using Apache
    int i4 = collectionGS.count("a1"::equals);
    long i5 = collection.stream().filter("a1"::equals).count(); // using stream JDK

    System.out.println("count = " + i1 + ":" + i2 + ":" + i3 + ":" + i4 + ":" + i5); // print count = 2:2:2:2:2
}
 

private static void testCount() {
    Collection<String> collection = Lists.newArrayList("a1", "a2", "a3", "a1");
    Iterable<String> iterable = collection;
    MutableCollection<String> collectionGS = FastList.newListWith("a1", "a2", "a3", "a1");

    // Вернуть количество вхождений объекта
    int i1 = Iterables.frequency(iterable, "a1"); // с помощью guava
    int i2 = Collections.frequency(collection, "a1"); // c помощью JDK
    int i3 = CollectionUtils.cardinality("a1", iterable); // c помощью Apache
    int i4 = collectionGS.count("a1"::equals);
    long i5 = collection.stream().filter("a1"::equals).count(); // c помощью stream JDK

    System.out.println("count = " + i1 + ":" + i2 + ":" + i3 + ":" + i4 + ":" + i5); // напечатает count = 2:2:2:2:2
}
 

/**
 * Format query using list substitution
 *
 * @param pattern Query that contains one or more %Ss
 * @param formatArgs Replacement strings for each %Ss occurrence, if there is just on replacement
 *     then all %sS instance would be replaced with it. If there is another mismatch between
 *     number of %Ss and replacement strings then the error is raised
 */
public static String normalizePattern(String pattern, List<String> formatArgs)
    throws QueryException {
  int numberOfSetsProvided =
      formatArgs.isEmpty() ? 0 : Iterables.frequency(formatArgs, SET_SEPARATOR) + 1;
  int numberOfSetsRequested = countMatches(pattern, SET_SUBSTITUTOR);

  // If they only provided one list as args, use that for every instance of `%Ss`
  if (numberOfSetsProvided == 1) {
    return pattern.replace(SET_SUBSTITUTOR, getSetRepresentation(formatArgs));
  }

  if (numberOfSetsProvided != numberOfSetsRequested) {
    String message =
        String.format(
            "Incorrect number of sets. Query uses `%s` %d times but %d sets were given",
            SET_SUBSTITUTOR, numberOfSetsRequested, numberOfSetsProvided);
    throw new QueryException(message);
  }

  List<String> unusedFormatArgs = formatArgs;
  String formattedQuery = pattern;
  while (formattedQuery.contains(SET_SUBSTITUTOR)) {
    int nextSeparatorIndex = unusedFormatArgs.indexOf(SET_SEPARATOR);
    List<String> currentSet =
        nextSeparatorIndex == -1
            ? unusedFormatArgs
            : unusedFormatArgs.subList(0, nextSeparatorIndex);
    // +1 so we don't include the separator in the next list
    unusedFormatArgs = unusedFormatArgs.subList(nextSeparatorIndex + 1, unusedFormatArgs.size());
    formattedQuery =
        formattedQuery.replaceFirst(SET_SUBSTITUTOR, getSetRepresentation(currentSet));
  }
  return formattedQuery;
}
 

@Test
public void frequency_of_object_in_collection_guava () {

	int numberOfOccurences = Iterables.frequency(words, "me");
	
	assertEquals(2, numberOfOccurences);
}