Example usage for java.util Iterator hasNext

Introduction

In this page you can find the example usage for java.util Iterator hasNext.

Prototype

boolean hasNext();

Source Link

Document

Returns true if the iteration has more elements.

Usage

From source file:Main.java

public static String getPrettyString(Collection<?> coll) {
    StringBuffer sb = new StringBuffer();
    Iterator<?> it = coll.iterator();

    while (it.hasNext()) {
        String s = it.next().toString();
        sb.append(s + "\n");
    }//from ww  w.j a v a  2  s .c  om

    return sb.toString().trim();
}

From source file:Main.java

public static void showList(List<? extends Object> lst) {
    Iterator<? extends Object> it = lst.iterator();
    while (it.hasNext()) {
        System.out.println(it.next());
    }//from w  w  w  .  j a  v a2 s. c  o m
}

From source file:Main.java

public static <T> Object getFirst(Iterable<T> c) {
    final Iterator<T> it = c.iterator();
    if (!it.hasNext()) {
        return null;
    } else {/*from w ww .  ja  v  a2  s  .  co m*/
        return it.next();
    }
}

From source file:Main.java

public static boolean isEmptyCollection(Collection<?> cols) {
    if (cols == null || cols.isEmpty()) {
        return true;
    }/*from  w ww  .  java  2 s  .  com*/
    Iterator<?> ite = cols.iterator();
    while (ite.hasNext()) {
        if (ite.next() == null) {
            return true;
        }
    }
    return false;
}

From source file:Main.java

public static <T, C extends Collection<? super T>> C addTo(final Iterator<T> iter, final C c) {
    while (iter.hasNext())
        c.add(iter.next());//w ww  .j a v a  2s  .  co  m
    return c;
}

From source file:Main.java

@SuppressWarnings("rawtypes")
public static List<String> keysToList(Map<?, ?> map) {
    List<String> list = new ArrayList<String>();
    Set<?> set = map.entrySet();
    Iterator<?> iter = set.iterator();
    while (iter.hasNext()) {
        Map.Entry m = (Map.Entry) iter.next();
        list.add("" + m.getKey());
    }//from ww w.j a va2 s.  c o  m
    return list;
}

From source file:Main.java

/**
 * Prints each object in the collection with commas between them.
 * Nulls will print as "null".  A null collection will cause NPE.
 *///from  w ww.  j  a v  a  2s.co m
public static String collectionToString(Collection col) {
    StringBuffer outputString = new StringBuffer(100);
    boolean firstItem = true;
    Iterator it = col.iterator();
    while (it.hasNext()) {
        if (!firstItem)
            outputString.append(", ");
        outputString.append(it.next());
        firstItem = false;
    }
    return outputString.toString();
}

From source file:Main.java

public static Object getFirstObject(Collection<?> collection) {
    Iterator<?> iterator = collection.iterator();

    if (iterator.hasNext()) {
        return iterator.next();
    } else {// w  ww  .  j  a  va2  s.c om
        return null;
    }
}

From source file:Main.java

/**
 * Compares two collections returning the number of elements they have in common
 * /*from  ww  w  . ja  va  2  s  .c o m*/
 * @param <T>
 * @param one
 * @param two
 * @return
 */
public static <T> int collectionCompare(Collection<T> one, Collection<T> two) {
    int count = 0;

    Iterator<T> e = one.iterator();
    while (e.hasNext()) {
        if (two.contains(e.next()))
            ++count;
    }

    return count;
}

From source file:Main.java

/**
 * Given an iterable A whose elements are iterables, this method will return the first
 * element of A.//from w  w w  .  j a va 2  s. c o m
 * If no such element exist, an empty iterable is returned rather than null.
 *
 *
 * @param iterable
 * @param <S>
 * @param <T>
 * @return
 */
public static <S, T extends Iterable<S>> Iterable<S> safeGetFirst(Iterable<T> iterable) {
    Iterator<T> it = iterable.iterator();

    return it.hasNext() ? it.next() : Collections.<S>emptySet();
}