Example usage for java.util Collection iterator

Introduction

In this page you can find the example usage for java.util Collection iterator.

Prototype

Iterator<E> iterator();

Source Link

Document

Returns an iterator over the elements in this collection.

Usage

From source file:Main.java

public static <T> void move(Collection<T> fromCollection, Collection<T> toCollection) {
    for (Iterator<T> i = fromCollection.iterator(); i.hasNext();) {
        T element = i.next();/*from  ww w .j  a  v a  2 s  . c  o  m*/
        i.remove();

        toCollection.add(element);
    }
}

From source file:Main.java

public static String dumpToString(Collection c, String separator) {
    String retval = "";
    for (Iterator it = c.iterator(); it.hasNext();) {
        retval += it.next().toString();//from   w  w  w . j av a  2s .c  om
        retval += separator;
    }
    return retval;
}

From source file:Main.java

/**
 * Brute force, for when HashSet and TreeSet won't work (e.g. #hashCode
 * implementation isn't appropriate). The original Collection is not
 * modified./*from  www  . j av a  2  s .c  om*/
 */
public static Collection removeDuplicates(Collection original) {
    ArrayList result = new ArrayList();
    for (Iterator i = original.iterator(); i.hasNext();) {
        Object item = i.next();
        if (!result.contains(item)) {
            result.add(item);
        }
    }

    return result;
}

From source file:Main.java

/**
 *  Get the first item in a list.  If there is no such item, return
 *  null./* w  w  w .ja v  a  2  s.  c  om*/
 */
public static <T> T first(Collection<T> list) {
    if (list == null || list.isEmpty())
        return null;

    return list.iterator().next();
}

From source file:Main.java

public static String join(Collection<String> strings, String separator) {
    Iterator<String> iter = strings.iterator();
    StringBuilder sb = new StringBuilder();
    if (iter.hasNext()) {
        sb.append(iter.next());//from  www . j  a v a 2 s.c om
        while (iter.hasNext()) {
            sb.append(separator).append(iter.next());
        }
    }
    return sb.toString();
}

From source file:Main.java

static String getContents(Collection c) {
    StringBuilder sb = new StringBuilder();
    for (Iterator it = c.iterator(); it.hasNext();) {
        sb.append(it.next());//from   www . ja  v  a2s  .  c  o  m
        if (it.hasNext()) {
            sb.append(", ");
        }
    }
    return sb.toString();
}

From source file:Main.java

public static <T> List<T> ToList2(Collection<T> values) {
    List<T> alllist = new ArrayList<T>();
    Iterator<T> iterator = values.iterator();
    T obj = null;/*from  w ww  .j  av  a 2s .  c o  m*/
    while (iterator.hasNext()) {
        obj = iterator.next();
        alllist.add(obj);
    }
    return alllist;
}

From source file:Main.java

public static <T extends Comparable<T>> int compare(Collection<T> lhs, Collection<T> rhs) {
    int cmp;// www  .ja  va2 s.  co m
    Iterator<T> lit = lhs.iterator();
    Iterator<T> rit = rhs.iterator();
    while (lit.hasNext() && rit.hasNext()) {
        cmp = lit.next().compareTo(rit.next());
        if (cmp != 0) {
            return cmp;
        }
    }
    return lhs.size() - rhs.size();
}

From source file:Main.java

/**
 * Creates new collection that does not contain nulls. Does not change input
 * collection. It uses raw collection - not parameterized.
 * {@link SuppressWarnings} annotation is added to avoid IDE to report
 * rawtypes and unchecked warnings.//from w  ww  .j a  v a  2 s.  com
 * 
 * @param c
 *            raw collection to create cleaned collection from.
 * @return collection without nulls
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public static Collection toCleanedRaw(Collection c) {
    ArrayList cleaned = new ArrayList();
    Iterator iterator = c.iterator();
    while (iterator.hasNext()) {
        Object e = iterator.next();
        if (e != null) {
            cleaned.add(e);
        }
    }
    return cleaned;
}

From source file:Main.java

public static <T extends Object> boolean isEqual(Collection<? extends T> coll, Comparator<? super T> comp) {

    Iterator<? extends T> i = coll.iterator();
    T first = i.next();//www . j  av a2  s.  co  m
    while (i.hasNext()) {
        T next = i.next();
        if (comp.compare(first, next) < 0) {
            return false;
        }
    }
    return true;
}