Example usage for java.util Iterator hasNext

List of usage examples for java.util Iterator hasNext

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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:DiameterMap.java

public static void main(String args[]) {
    String names[] = { "Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune", "Pluto" };
    float diameters[] = { 4800f, 12103.6f, 12756.3f, 6794f, 142984f, 120536f, 51118f, 49532f, 2274f };
    Map map = new TreeMap();
    for (int i = 0, n = names.length; i < n; i++) {
        map.put(names[i], new Float(diameters[i]));
    }//from  w w w. j av  a 2 s  .  com
    Iterator it = map.keySet().iterator();
    Object obj;
    while (it.hasNext()) {
        obj = it.next();
        System.out.println(obj + ": " + map.get(obj));
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Object keyObject = "";
    Object valueObject = "";
    Map<Object, Object> weakMap = new WeakHashMap<Object, Object>();

    weakMap.put(keyObject, valueObject);
    WeakReference weakValue = new WeakReference<Object>(valueObject);

    weakMap.put(keyObject, weakValue);/*  w ww  .  j a v  a  2 s  .  c om*/

    Iterator it = weakMap.keySet().iterator();
    while (it.hasNext()) {
        Object key = it.next();
        weakValue = (WeakReference) weakMap.get(key);
        if (weakValue == null) {
            System.out.println("Value has been garbage-collected");
        } else {
            System.out.println("Get value");
            valueObject = weakValue.get();
        }
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Map<String, Integer> map = new HashMap<String, Integer>();
    map = new TreeMap();

    map.put("a", new Integer(1));
    map.put("b", new Integer(2));
    map.put("c", new Integer(3));

    int size = map.size(); // 2

    Object oldValue = map.put("a", new Integer(9)); // 1

    oldValue = map.remove("c"); // 3

    Iterator it = map.keySet().iterator();
    while (it.hasNext()) {
        Object key = it.next();/*  w w w  . j a  v  a 2 s . c o  m*/
    }

    it = map.values().iterator();
    while (it.hasNext()) {
        Object value = it.next();
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Object keyObject = "";
    Object valueObject = "";
    Map weakMap = new WeakHashMap();

    weakMap.put(keyObject, valueObject);
    WeakReference weakValue = new WeakReference(valueObject);

    weakMap.put(keyObject, weakValue);/*w  w  w  .j  av a  2  s.c om*/

    Iterator it = weakMap.keySet().iterator();
    while (it.hasNext()) {
        Object key = it.next();
        weakValue = (WeakReference) weakMap.get(key);
        if (weakValue == null) {
            System.out.println("Value has been garbage-collected");
        } else {
            System.out.println("Get value");
            valueObject = weakValue.get();
        }
    }
}

From source file:Main.java

public static void main(String[] a) {
    Map<String, String> yourMap = new HashMap<String, String>();
    yourMap.put("1", "one");
    yourMap.put("2", "two");
    yourMap.put("3", "three");

    Map<String, Object> map = new LinkedHashMap<String, Object>();

    List<String> keyList = new ArrayList<String>(yourMap.keySet());
    List<String> valueList = new ArrayList<String>(yourMap.values());
    Set<String> sortedSet = new TreeSet<String>(valueList);

    Object[] sortedArray = sortedSet.toArray();
    int size = sortedArray.length;

    for (int i = 0; i < size; i++) {
        map.put(keyList.get(valueList.indexOf(sortedArray[i])), sortedArray[i]);
    }//from ww  w  . j  av a 2  s. c om

    Set ref = map.keySet();
    Iterator it = ref.iterator();

    while (it.hasNext()) {
        String i = (String) it.next();
        System.out.println(i);
    }
}

From source file:SetDemo.java

public static void main(String[] args) {
    String[] letters = { "A", "B", "C", "D", "E" };

    Set s = new HashSet();

    for (int i = 0; i < letters.length; i++)
        s.add(letters[i]);/* ww w . j  ava  2  s  . com*/

    if (!s.add(letters[0]))
        System.out.println("Cannot add a duplicate.\n");

    Iterator iter = s.iterator();
    while (iter.hasNext())
        System.out.println(iter.next());

    System.out.println("");

    SortedSet ss = new TreeSet();

    for (int i = 0; i < letters.length; i++)
        ss.add(letters[i]);

    if (!ss.add(letters[0]))
        System.out.println("Cannot add a duplicate.\n");

    iter = ss.iterator();
    while (iter.hasNext())
        System.out.println(iter.next());
}

From source file:HTDemo2.java

public static void main(String args[]) {
    Hashtable<String, Double> balance = new Hashtable<String, Double>();

    String str;// w ww  .j a va2  s.  co  m
    double bal;

    balance.put("A", 3434.34);
    balance.put("B", 123.22);
    balance.put("C", 1378.00);
    balance.put("D", 99.22);
    balance.put("E", -19.08);

    Set<String> set = balance.keySet();

    Iterator<String> itr = set.iterator();
    while (itr.hasNext()) {
        str = itr.next();
        System.out.println(str + ": " + balance.get(str));
    }

    System.out.println();

    bal = balance.get("A");
    balance.put("A", bal + 1000);
    System.out.println("A's new balance: " + balance.get("A"));
}

From source file:Main.java

public static void main(String[] args) {
    Map<String, int[]> map = new TreeMap<String, int[]>();

    int[] array = new int[3];
    array[0] = 0;/*from  w  w  w.java  2  s. c om*/
    array[1] = 1;
    array[2] = 2;
    map.put("array", array);

    Iterator<String> iter = map.keySet().iterator();

    while (iter.hasNext()) {
        String arrayName = iter.next();
        array = map.get(arrayName);
        System.out.print(arrayName + ":");
        for (int i = 0; i < array.length; i++) {
            System.out.print(array[i]);
        }
    }
}

From source file:Main.java

public static void main(String[] args) {

    TreeSet<Integer> treeadd = new TreeSet<Integer>();

    treeadd.add(1);/*from   w w w .  j  ava2  s.  co  m*/
    treeadd.add(13);
    treeadd.add(17);
    treeadd.add(2);

    // create descending iterator
    Iterator<Integer> iterator = treeadd.descendingIterator();

    while (iterator.hasNext()) {
        System.out.println(iterator.next());
    }
}

From source file:Main.java

public static void main(String[] args) {
    Map charsets = Charset.availableCharsets();
    Iterator iterator = charsets.values().iterator();
    while (iterator.hasNext()) {
        Charset cs = (Charset) iterator.next();
        System.out.print(cs.displayName());
        if (cs.isRegistered()) {
            System.out.print(" (registered): ");
        } else {//from  ww w .ja v  a2  s.  c om
            System.out.print(" (unregistered): ");
        }
        System.out.print(cs.name());
        Iterator names = cs.aliases().iterator();
        while (names.hasNext()) {
            System.out.print(", ");
            System.out.print(names.next());
        }
        System.out.println();
    }
}