treemap.java

This is a resource based on j2me embedded,if you dont understand,you can connection with me .

     */
    private Entry getPrecedingEntry(Object key) {
        Entry p = root;
        if (p==null)
            return null;

        while (true) {
            int cmp = compare(key, p.key);
            if (cmp > 0) {
                if (p.right != null)
                    p = p.right;
                else
                    return p;
            } else {
                if (p.left != null) {
                    p = p.left;
                } else {
                    Entry parent = p.parent;
                    Entry ch = p;
                    while (parent != null && ch == parent.left) {
                        ch = parent;
                        parent = parent.parent;
                    }
                    return parent;
                }
            }
        }
    }

    /**
     * Returns the key corresonding to the specified Entry.  Throw 
     * NoSuchElementException if the Entry is <tt>null</tt>.
     */
    private static Object key(Entry e) {
        if (e==null)
            throw new NoSuchElementException();
        return e.key;
    }

    /**
     * Associates the specified value with the specified key in this map.
     * If the map previously contained a mapping for this key, the old
     * value is replaced.
     *
     * @param key key with which the specified value is to be associated.
     * @param value value to be associated with the specified key.
     * 
     * @return previous value associated with specified key, or <tt>null</tt>
     *         if there was no mapping for key.  A <tt>null</tt> return can
     *         also indicate that the map previously associated <tt>null</tt>
     *         with the specified key.
     * @throws    ClassCastException key cannot be compared with the keys
     *            currently in the map.
     * @throws NullPointerException key is <tt>null</tt> and this map uses
     *         natural order, or its comparator does not tolerate
     *         <tt>null</tt> keys.
     */
    public Object put(Object key, Object value) {
        Entry t = root;

        if (t == null) {
            incrementSize();
            root = new Entry(key, value, null);
            return null;
       }

        while (true) {
            int cmp = compare(key, t.key);
            if (cmp == 0) {
                return t.setValue(value);
            } else if (cmp < 0) {
                if (t.left != null) {
                    t = t.left;
                } else {
                    incrementSize();
                    t.left = new Entry(key, value, t);
                    fixAfterInsertion(t.left);
                    return null;
                }
            } else { // cmp > 0
                if (t.right != null) {
                    t = t.right;
                } else {
                    incrementSize();
                    t.right = new Entry(key, value, t);
                    fixAfterInsertion(t.right);
                    return null;
                }
            }
        }
    }

    /**
     * Removes the mapping for this key from this TreeMap if present.
     *
     * @param  key key for which mapping should be removed
     * @return previous value associated with specified key, or <tt>null</tt>
     *         if there was no mapping for key.  A <tt>null</tt> return can
     *         also indicate that the map previously associated
     *         <tt>null</tt> with the specified key.
     * 
     * @throws    ClassCastException key cannot be compared with the keys
     *            currently in the map.
     * @throws NullPointerException key is <tt>null</tt> and this map uses
     *         natural order, or its comparator does not tolerate
     *         <tt>null</tt> keys.
     */
    public Object remove(Object key) {
        Entry p = getEntry(key);
        if (p == null)
            return null;

        Object oldValue = p.value;
        deleteEntry(p);
        return oldValue;
    }

    /**
     * Removes all mappings from this TreeMap.
     */
    public void clear() {
        modCount++;
        size = 0;
        root = null;
    }

    /**
     * Returns a shallow copy of this <tt>TreeMap</tt> instance. (The keys and
     * values themselves are not cloned.)
     *
     * @return a shallow copy of this Map.
     */
    public Object clone() {
        TreeMap clone = null;
        try { 
            clone = (TreeMap)super.clone();
        } catch (CloneNotSupportedException e) { 
            throw new InternalError();
        }

        // Put clone into "virgin" state (except for comparator)
        clone.root = null;
        clone.size = 0;
        clone.modCount = 0;
        clone.entrySet = null;

        // Initialize clone with our mappings
        try {
            clone.buildFromSorted(size, entrySet().iterator(), null, null);
        } catch (java.io.IOException cannotHappen) {
        } catch (ClassNotFoundException cannotHappen) {
        }

        return clone;
    }


    // Views

    /**
     * This field is initialized to contain an instance of the entry set
     * view the first time this view is requested.  The view is stateless,
     * so there's no reason to create more than one.
     */
    private transient volatile Set entrySet = null;

    /**
     * Returns a Set view of the keys contained in this map.  The set's
     * iterator will return the keys in ascending order.  The map is backed by
     * this <tt>TreeMap</tt> instance, so changes to this map are reflected in
     * the Set, and vice-versa.  The Set supports element removal, which
     * removes the corresponding mapping from the map, via the
     * <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, <tt>removeAll</tt>,
     * <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not support
     * the <tt>add</tt> or <tt>addAll</tt> operations.
     *
     * @return a set view of the keys contained in this TreeMap.
     */
    public Set keySet() {
        if (keySet == null) {
            keySet = new AbstractSet() {
                public Iterator iterator() {
                    return new KeyIterator();
                }

                public int size() {
                    return TreeMap.this.size();
                }

                public boolean contains(Object o) {
                    return containsKey(o);
                }

                public boolean remove(Object o) {
                    int oldSize = size;
                    TreeMap.this.remove(o);
                    return size != oldSize;
                }

                public void clear() {
                    TreeMap.this.clear();
                }
            };
        }
        return keySet;
    }

    /**
     * Returns a collection view of the values contained in this map.  The
     * collection's iterator will return the values in the order that their
     * corresponding keys appear in the tree.  The collection is backed by
     * this <tt>TreeMap</tt> instance, so changes to this map are reflected in
     * the collection, and vice-versa.  The collection supports element
     * removal, which removes the corresponding mapping from the map through
     * the <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
     * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
     * It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
     *
     * @return a collection view of the values contained in this map.
     */
    public Collection values() {
        if (values == null) {
            values = new AbstractCollection() {
                public Iterator iterator() {
                    return new ValueIterator();
                }

                public int size() {
                    return TreeMap.this.size();
                }

                public boolean contains(Object o) {
                    for (Entry e = firstEntry(); e != null; e = successor(e))
                        if (valEquals(e.getValue(), o))
                            return true;
                    return false;
                }

                public boolean remove(Object o) {
                    for (Entry e = firstEntry(); e != null; e = successor(e)) {
                        if (valEquals(e.getValue(), o)) {
                            deleteEntry(e);
                            return true;
                        }
                    }
                    return false;
                }

                public void clear() {
                    TreeMap.this.clear();
                }
            };
        }
        return values;
    }

    /**
     * Returns a set view of the mappings contained in this map.  The set's
     * iterator returns the mappings in ascending key order.  Each element in
     * the returned set is a <tt>Map.Entry</tt>.  The set is backed by this
     * map, so changes to this map are reflected in the set, and vice-versa.
     * The set supports element removal, which removes the corresponding
     * mapping from the TreeMap, through the <tt>Iterator.remove</tt>,
     * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt> and
     * <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
     * <tt>addAll</tt> operations.
     *
     * @return a set view of the mappings contained in this map.
     * @see Map.Entry
     */
    public Set entrySet() {
        if (entrySet == null) {
            entrySet = new AbstractSet() {
                public Iterator iterator() {
                    return new EntryIterator();
                }

                public boolean contains(Object o) {
                    if (!(o instanceof Map.Entry))
                        return false;
                    Map.Entry entry = (Map.Entry)o;
                    Object value = entry.getValue();
                    Entry p = getEntry(entry.getKey());
                    return p != null && valEquals(p.getValue(), value);
                }

                public boolean remove(Object o) {
                    if (!(o instanceof Map.Entry))
                        return false;
                    Map.Entry entry = (Map.Entry)o;
                    Object value = entry.getValue();
                    Entry p = getEntry(entry.getKey());
                    if (p != null && valEquals(p.getValue(), value)) {
                        deleteEntry(p);
                        return true;
                    }
                    return false;
                }

                public int size() {
                    return TreeMap.this.size();
                }

                public void clear() {
                    TreeMap.this.clear();
                }
            };
        }
        return entrySet;
    }

    /**
     * Returns a view of the portion of this map whose keys range from
     * <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive.  (If
     * <tt>fromKey</tt> and <tt>toKey</tt> are equal, the returned sorted map
     * is empty.)  The returned sorted map is backed by this map, so changes
     * in the returned sorted map are reflected in this map, and vice-versa.
     * The returned sorted map supports all optional map operations.<p>
     *
     * The sorted map returned by this method will throw an
     * <tt>IllegalArgumentException</tt> if the user attempts to insert a key
     * less than <tt>fromKey</tt> or greater than or equal to
     * <tt>toKey</tt>.<p>
     *
     * Note: this method always returns a <i>half-open range</i> (which
     * includes its low endpoint but not its high endpoint).  If you need a
     * <i>closed range</i> (which includes both endpoints), and the key type
     * allows for calculation of the successor a given key, merely request the
     * subrange from <tt>lowEndpoint</tt> to <tt>successor(highEndpoint)</tt>.
     * For example, suppose that <tt>m</tt> is a sorted map whose keys are
     * strings.  The following idiom obtains a view containing all of the
     * key-value mappings in <tt>m</tt> whose keys are between <tt>low</tt>
     * and <tt>high</tt>, inclusive:
     *             <pre>    SortedMap sub = m.submap(low, high+"\0");</pre>
     * A similar technique can be used to generate an <i>open range</i> (which
     * contains neither endpoint).  The following idiom obtains a view
     * containing all of the key-value mappings in <tt>m</tt> whose keys are
     * between <tt>low</tt> and <tt>high</tt>, exclusive:
     *             <pre>    SortedMap sub = m.subMap(low+"\0", high);</pre>
     *
     * @param fromKey low endpoint (inclusive) of the subMap.
     * @param toKey high endpoint (exclusive) of the subMap.
     * 
     * @return a view of the portion of this map whose keys range from
     *                <tt>fromKey</tt>, inclusive, to <tt>toKey</tt>, exclusive.
     * 
     * @throws ClassCastException if <tt>fromKey</tt> and <tt>toKey</tt>
     *         cannot be compared to one another using this map's comparator
     *         (or, if the map has no comparator, using natural ordering).
     * @throws IllegalArgumentException if <tt>fromKey</tt> is greater than
     *         <tt>toKey</tt>.
     * @throws NullPointerException if <tt>fromKey</tt> or <tt>toKey</tt> is
     *               <tt>null</tt> and this map uses natural order, or its
     *               comparator does not tolerate <tt>null</tt> keys.
     */
    public SortedMap subMap(Object fromKey, Object toKey) {
        return new SubMap(fromKey, toKey);
    }

    /**
     * Returns a view of the portion of this map whose keys are strictly less
     * than <tt>toKey</tt>.  The returned sorted map is backed by this map, so
     * changes in the returned sorted map are reflected in this map, and
     * vice-versa.  The returned sorted map supports all optional map
     * operations.<p>
     *
     * The sorted map returned by this method will throw an
     * <tt>IllegalArgumentException</tt> if the user attempts to insert a key
     * greater than or equal to <tt>toKey</tt>.<p>
     *
     * Note: this method always returns a view that does not contain its
     * (high) endpoint.  If you need a view that does contain this endpoint,
     * and the key type allows for calculation of the successor a given key,
     * merely request a headMap bounded by <tt>successor(highEndpoint)</tt>.
     * For example, suppose that suppose that <tt>m</tt> is a sorted map whose
     * keys are strings.  The following idiom obtains a view containing all of
     * the key-value mappings in <tt>m</tt> whose keys are less than or equal
     * to <tt>high</tt>:
     * <pre>
     *     SortedMap head = m.headMap(high+"\0");
     * </pre>
     *
     * @param toKey high endpoint (exclusive) of the headMap.
     * @return a view of the portion of this map whose keys are strictly
     *                less than <tt>toKey</tt>.
     *
     * @throws ClassCastException if <tt>toKey</tt> is not compatible
     *         with this map's comparator (or, if the map has no comparator,
     *         if <tt>toKey</tt> does not implement <tt>Comparable</tt>).
     * @throws IllegalArgumentException if this map is itself a subMap,
     *         headMap, or tailMap, and <tt>toKey</tt> is not within the
     *         specified range of the subMap, headMap, or tailMap.
     * @throws NullPointerException if <tt>toKey</tt> is <tt>null</tt> and
     *               this map uses natural order, or its comparator does not
     *               tolerate <tt>null</tt> keys.
     */
    public SortedMap headMap(Object toKey) {
        return new SubMap(toKey, true);
    }

    /**
     * Returns a view of the portion of this map whose keys are greater than
     * or equal to <tt>fromKey</tt>.  The returned sorted map is backed by
     * this map, so changes in the returned sorted map are reflected in this
     * map, and vice-versa.  The returned sorted map supports all optional map
     * operations.<p>
     *
     * The sorted map returned by this method will throw an
     * <tt>IllegalArgumentException</tt> if the user attempts to insert a key
     * less than <tt>fromKey</tt>.<p>
     *
     * Note: this method always returns a view that contains its (low)
     * endpoint.  If you need a view that does not contain this endpoint, and
     * the element type allows for calculation of the successor a given value,
     * merely request a tailMap bounded by <tt>successor(lowEndpoint)</tt>.