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 <T> T getFirstNonNull(Collection<T> c) {
    T ret = null;//  w  w  w .j  a v a 2s .c om
    Iterator<T> it = c.iterator();
    while (it.hasNext() && ret == null) {
        T t = it.next();
        if (t != null)
            ret = t;
    }
    return ret;
}

From source file:Main.java

public static <K> Object firstElementOrNull(Iterable iterable) {
    Iterator iterator = iterable.iterator();
    if (iterator.hasNext()) {
        return iterator.next();
    } else {//from  w  w w  . ja  v a2  s.c om
        return null;
    }
}

From source file:Main.java

public static boolean hasNotItems(Iterator<?> iters) {
    return (iters != null) && (iters.hasNext());
}

From source file:Main.java

public static <T> List<T> subtract(Collection<T> a, Collection<T> b) {
    ArrayList list = new ArrayList(a);
    Iterator i$ = b.iterator();

    while (i$.hasNext()) {
        Object element = i$.next();
        list.remove(element);/*from  w w w . j a v  a  2 s  . c o  m*/
    }

    return list;
}

From source file:Main.java

/**
 * Add all items in iterator to target collection
 * @param <T>/*  w ww .jav  a 2s  .  com*/
 * @param <U>
 * @param source
 * @param target
 * @return
 */
public static <T, U extends Collection<T>> U addAll(Iterator<T> source, U target) {
    while (source.hasNext()) {
        target.add(source.next());
    }
    return target; // for chaining
}

From source file:Main.java

public static <T> T getSingleElement(Collection<T> collection) {
    Iterator<T> iterator = collection.iterator();
    return iterator.hasNext() ? iterator.next() : null;
}

From source file:Main.java

public static ArrayList<String> getHashMap(HashMap<String, String> hm) {
    ArrayList<String> a = new ArrayList<String>();
    Set s = hm.entrySet();// ww w . j a va 2  s .co m
    Iterator it = s.iterator();
    while (it.hasNext()) {
        Map.Entry m = (Map.Entry) it.next();
        a.add(m.getKey() + "\t" + m.getValue());
    }
    return a;
}

From source file:Main.java

/**
 * Adds all elements in the iteration to the given collection.
 * //from   ww  w  . j  a va2 s  .  co  m
 * @param collection  the collection to add to, must not be null
 * @param iterator  the iterator of elements to add, must not be null
 * @throws NullPointerException if the collection or iterator is null
 */
public static <T> void addAll(Collection<T> collection, Iterator<T> iterator) {
    while (iterator.hasNext()) {
        collection.add(iterator.next());
    }
}

From source file:Main.java

public static String getClasspathString(List<File> c) {
    StringBuilder sb = new StringBuilder();
    Iterator<File> i = c.iterator();
    if (i.hasNext()) {
        sb.append(i.next().getAbsolutePath());
        while (i.hasNext()) {
            sb.append(File.pathSeparatorChar);
            sb.append(i.next().getAbsolutePath());
        }//from ww  w  .  j  a va2  s  .c o  m
    }
    return sb.toString();
}

From source file:Main.java

@SuppressWarnings("rawtypes")
public static String getKeyByValue(Map<?, String> hm, String value) {
    Set<?> s = hm.entrySet();
    Iterator<?> it = s.iterator();
    while (it.hasNext()) {
        Map.Entry m = (Map.Entry) it.next();
        if (m.getValue().equals(value))
            return m.getKey() + "";
    }/*w  w  w. j a va2 s  .c om*/
    return null;
}