fastarraylist.java

初级java程序员如果想要更深一步提高自己的实力

                    List sub = get(temp);
                    boolean r = sub.removeAll(o);
                    if (r) last = first + sub.size();
                    list = temp;
                    expected = temp;
                    return r;
                }
            } else {
                synchronized (list) {
                    return get(expected).removeAll(o);
                }
            }
        }

        public boolean retainAll(Collection o) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    List sub = get(temp);
                    boolean r = sub.retainAll(o);
                    if (r) last = first + sub.size();
                    list = temp;
                    expected = temp;
                    return r;
                }
            } else {
                synchronized (list) {
                    return get(expected).retainAll(o);
                }
            }
        }

        public int size() {
            if (fast) {
                return get(expected).size();
            } else {
                synchronized (list) {
                    return get(expected).size();
                }
            }
        }


        public boolean isEmpty() {
            if (fast) {
                return get(expected).isEmpty();
            } else {
                synchronized (list) {
                    return get(expected).isEmpty();
                }
            }
        }

        public boolean contains(Object o) {
            if (fast) {
                return get(expected).contains(o);
            } else {
                synchronized (list) {
                    return get(expected).contains(o);
                }
            }
        }

        public boolean containsAll(Collection o) {
            if (fast) {
                return get(expected).containsAll(o);
            } else {
                synchronized (list) {
                    return get(expected).containsAll(o);
                }
            }
        }

        public Object[] toArray(Object[] o) {
            if (fast) {
                return get(expected).toArray(o);
            } else {
                synchronized (list) {
                    return get(expected).toArray(o);
                }
            }
        }

        public Object[] toArray() {
            if (fast) {
                return get(expected).toArray();
            } else {
                synchronized (list) {
                    return get(expected).toArray();
                }
            }
        }


        public boolean equals(Object o) {
            if (o == this) return true;
            if (fast) {
                return get(expected).equals(o);
            } else {
                synchronized (list) {
                    return get(expected).equals(o);
                }
            }
        }

        public int hashCode() {
            if (fast) {
                return get(expected).hashCode();
            } else {
                synchronized (list) {
                    return get(expected).hashCode();
                }
            }
        }

        public boolean add(Object o) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    boolean r = get(temp).add(o);
                    if (r) last++;
                    list = temp;
                    expected = temp;
                    return r;
                }
            } else {
                synchronized (list) {
                    return get(expected).add(o);
                }
            }
        }

        public boolean addAll(Collection o) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    boolean r = get(temp).addAll(o);
                    if (r) last += o.size();
                    list = temp;
                    expected = temp;
                    return r;
                }
            } else {
                synchronized (list) {
                    return get(expected).addAll(o);
                }
            }
        }

        public void add(int i, Object o) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    get(temp).add(i, o);
                    last++;
                    list = temp;
                    expected = temp;
                }
            } else {
                synchronized (list) {
                    get(expected).add(i, o);
                }
            }
        }

        public boolean addAll(int i, Collection o) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    boolean r = get(temp).addAll(i, o);
                    list = temp;
                    if (r) last += o.size();
                    expected = temp;
                    return r;
                }
            } else {
                synchronized (list) {
                    return get(expected).addAll(i, o);
                }
            }
        }

        public Object remove(int i) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    Object o = get(temp).remove(i);
                    last--;
                    list = temp;
                    expected = temp;
                    return o;
                }
            } else {
                synchronized (list) {
                    return get(expected).remove(i);
                }
            }
        }

        public Object set(int i, Object a) {
            if (fast) {
                synchronized (FastArrayList.this) {
                    ArrayList temp = (ArrayList) list.clone();
                    Object o = get(temp).set(i, a);
                    list = temp;
                    expected = temp;
                    return o;
                }
            } else {
                synchronized (list) {
                    return get(expected).set(i, a);
                }
            }
        }


        public Iterator iterator() {
            return new SubListIter(0);
        }

        public ListIterator listIterator() {
            return new SubListIter(0);
        }

        public ListIterator listIterator(int i) {
            return new SubListIter(i);
        }


        public Object get(int i) {
            if (fast) {
                return get(expected).get(i);
            } else {
                synchronized (list) {
                    return get(expected).get(i);
                }
            }
        }

        public int indexOf(Object o) {
            if (fast) {
                return get(expected).indexOf(o);
            } else {
                synchronized (list) {
                    return get(expected).indexOf(o);
                }
            }
        }


        public int lastIndexOf(Object o) {
            if (fast) {
                return get(expected).lastIndexOf(o);
            } else {
                synchronized (list) {
                    return get(expected).lastIndexOf(o);
                }
            }
        }


        public List subList(int f, int l) {
            if (list != expected) {
                throw new ConcurrentModificationException();
            }
            return new SubList(first + f, f + l);
        }


    private class SubListIter implements ListIterator {

        private List expected;
        private ListIterator iter;
        private int lastReturnedIndex = -1;


        public SubListIter(int i) {
            this.expected = list;
            this.iter = SubList.this.get(expected).listIterator(i);
        }

        private void checkMod() {
            if (list != expected) {
                throw new ConcurrentModificationException();
            }
        }

        List get() {
            return SubList.this.get(expected);
        }

        public boolean hasNext() {
            checkMod();
            return iter.hasNext();     
        }

        public Object next() {
            checkMod();
            lastReturnedIndex = iter.nextIndex();
            return iter.next();
        }

        public boolean hasPrevious() {
            checkMod();
            return iter.hasPrevious();
        }

        public Object previous() {
            checkMod();
            lastReturnedIndex = iter.previousIndex();
            return iter.previous();
        }

        public int previousIndex() {
            checkMod();
            return iter.previousIndex();
        }

        public int nextIndex() {
            checkMod();
            return iter.nextIndex();
        }

        public void remove() {
            checkMod();
            if (lastReturnedIndex < 0) {
                throw new IllegalStateException();
            }
            get().remove(lastReturnedIndex);
            last--;
            expected = list;
            iter = get().listIterator(lastReturnedIndex);
            lastReturnedIndex = -1;
        }

        public void set(Object o) {
            checkMod();
            if (lastReturnedIndex < 0) {
                throw new IllegalStateException();
            }
            get().set(lastReturnedIndex, o);
            expected = list;
            iter = get().listIterator(previousIndex() + 1);
        } 

        public void add(Object o) {
            checkMod();
            int i = nextIndex();
            get().add(i, o);
            last++;
            expected = list;
            iter = get().listIterator(i + 1);
            lastReturnedIndex = -1;
        }

   }


    }



    private class ListIter implements ListIterator {

        private List expected;
        private ListIterator iter;
        private int lastReturnedIndex = -1;


        public ListIter(int i) {
            this.expected = list;
            this.iter = get().listIterator(i);
        }

        private void checkMod() {
            if (list != expected) {
                throw new ConcurrentModificationException();
            }
        }

        List get() {
            return expected;
        }

        public boolean hasNext() {
            return iter.hasNext();     
        }

        public Object next() {
            lastReturnedIndex = iter.nextIndex();
            return iter.next();
        }

        public boolean hasPrevious() {
            return iter.hasPrevious();
        }

        public Object previous() {
            lastReturnedIndex = iter.previousIndex();
            return iter.previous();
        }

        public int previousIndex() {
            return iter.previousIndex();
        }

        public int nextIndex() {
            return iter.nextIndex();
        }

        public void remove() {
            checkMod();
            if (lastReturnedIndex < 0) {
                throw new IllegalStateException();
            }
            get().remove(lastReturnedIndex);
            expected = list;
            iter = get().listIterator(lastReturnedIndex);
            lastReturnedIndex = -1;
        }

        public void set(Object o) {
            checkMod();
            if (lastReturnedIndex < 0) {
                throw new IllegalStateException();
            }
            get().set(lastReturnedIndex, o);
            expected = list;
            iter = get().listIterator(previousIndex() + 1);
        } 

        public void add(Object o) {
            checkMod();
            int i = nextIndex();
            get().add(i, o);
            expected = list;
            iter = get().listIterator(i + 1);
            lastReturnedIndex = -1;
        }

   }
}