Example usage for java.util Map keySet

Introduction

In this page you can find the example usage for java.util Map keySet.

Prototype

Set<K> keySet();

Source Link

Document

Returns a Set view of the keys contained in this map.

Usage

From source file:Main.java

public static <V> void appendMaps(Map<Integer, V> A, Map<Integer, V> B) {
    int index = A.size();
    for (int i : B.keySet()) {
        A.put(index, B.get(i));/*from   w  w  w .ja  v  a2  s.  co m*/
        index++;
    }
}

From source file:Main.java

/**
 * Make a list map immutable./* www .ja  v  a 2s . com*/
 *
 * @param listMap
 *            the list map in input.
 * @return the immutable list map.
 */
public static <C, E> Map<C, List<E>> makeListMapImmutable(Map<C, List<E>> listMap) {
    for (C key : listMap.keySet()) {
        listMap.put(key, Collections.unmodifiableList(listMap.get(key)));
    }

    return Collections.unmodifiableMap(listMap);
}

From source file:Main.java

public static void listKeys(Map<String, String> map) {
    System.out.println("Key Set:");
    Set<String> keys = map.keySet();
    keys.forEach(System.out::println);
    System.out.println();/* w w  w.ja  v a 2s .c  om*/
}

From source file:Main.java

public static void dumpCurrentSharedPrerence(SharedPreferences pref) {
    Map<String, ?> map = pref.getAll();
    Iterator<String> ite = map.keySet().iterator();
    while (ite.hasNext()) {
        String key = ite.next();/*from  w  w w  .ja va 2 s  .  c om*/
        Log.d(TAG, "dump " + key + " : " + String.valueOf(map.get(key)));
    }
}

From source file:Main.java

/**
 * Returns map keys list./*from   www.  j  a  v  a 2s  .com*/
 *
 * @param map
 *            map to process
 * @param <K>
 *            key object type
 * @param <V>
 *            value object type
 * @return map keys list
 */
public static <K, V> ArrayList<K> keysList(final Map<K, V> map) {
    return new ArrayList<K>(map.keySet());
}

From source file:Main.java

private static void print(String text, Map<String, Double> map) {
    System.out.println(text);/*ww  w.java 2s  .com*/

    for (String key : map.keySet()) {
        System.out.println("key/value: " + key + "/" + map.get(key));
    }
}

From source file:Main.java

/**
 * Applies a function to the keys of the map. Note: Uses a for-each loop.
 *
 * @param map      The map with the keys the function will be applied to.
 * @param function The function to apply.
 *//*from www  . j a  v  a  2 s  .c o m*/
public static <I, K extends I> void applyToKeys(Map<K, ?> map, Function<I, ?> function) {
    for (K key : map.keySet())
        function.apply(key);
}

From source file:Main.java

/** Take key and value pairs from source and create map from value to key in target. */
public static <K, V> void reverse(Map<K, V> source, Map<V, K> target) {
    Iterator<K> i = source.keySet().iterator();
    while (i.hasNext()) {
        K key = i.next();// w  w w  .  j  av  a2 s .  c  o  m
        V value = source.get(key);
        target.put(value, key);
    }
}

From source file:Main.java

public static void clearNullElement(Map map) {
    if (map == null)
        return;/*from  ww  w.j  ava  2 s .c  om*/
    Object[] vs = map.keySet().toArray();
    for (Object o : vs) {
        if (null == map.get(o))
            map.remove(o);
    }
}

From source file:Main.java

public static void clearNullElement(Map<?, ?> map) {
    if (map == null)
        return;/*from ww  w  .j  a v a2  s. c om*/
    Object[] vs = map.keySet().toArray();
    for (Object o : vs) {
        if (null == map.get(o))
            map.remove(o);
    }
}