Java数据结构Vetor
Java数据结构Vector
/** * <html> * <body> * <P> Copyright JasonInternational</p> * <p> All rights reserved.</p> * <p> Created on 2018年6月29日 上午9:00:48</p> * <p> Created by Jason </p> * </body> * </html> */ package cn.ucaner.sourceanalysis.list; import java.util.AbstractList; import java.util.Arrays; import java.util.BitSet; import java.util.Collection; import java.util.Comparator; import java.util.ConcurrentModificationException; import java.util.Enumeration; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import java.util.NoSuchElementException; import java.util.Objects; import java.util.RandomAccess; import java.util.Spliterator; import java.util.function.Consumer; import java.util.function.Predicate; import java.util.function.UnaryOperator; /** * @Package:cn.ucaner.sourceanalysis * @ClassName:Vector * @Description: <p> Vector Vector 可实现自动增长的对象数组</p> * @Author: - Jason * @CreatTime:2018年6月29日 上午9:00:48 * @Modify By: * @ModifyTime: 2018年6月29日 * @Modify marker: * @version V1.0 */ /****************Notice****************** [参考]{@link https://www.cnblogs.com/zheting/p/7708366.html} {@link https://www.cnblogs.com/skywang12345/p/3308833.html} Vector 是矢量队列,它是JDK1.0版本添加的类。继承于AbstractList,实现了List, RandomAccess, Cloneable这些接口 Vector 继承了AbstractList,实现了List;所以,它是一个队列,支持相关的添加、删除、修改、遍历等功能. Vector 实现了RandmoAccess接口,即提供了随机访问功能. RandmoAccess是Java中用来被List实现,为List提供快速访问功能的. 在Vector中,我们即可以通过元素的序号快速获取元素对象;这就是快速随机访问。 Vector 实现了Cloneable接口,即实现clone()函数,它能被克隆,与ArrayList不同,Vector中的操作是线程安全的. Vector共有4个构造函数 Vector()// 默认构造函数 Vector(int capacity)// capacity是Vector的默认容量大小。当由于增加数据导致容量增加时,每次容量会增加一倍。 Vector(int capacity, int capacityIncrement)// capacity是Vector的默认容量大小,capacityIncrement是每次Vector容量增加时的增量值。 Vector(Collection<? extends E> collection)// 创建一个包含collection的Vector *******************End**************************/ public class Vector<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, java.io.Serializable{ private static final long serialVersionUID = 2411957469099220630L; /** * 元素数据 - elementData是个动态数组,如果初始化Vector时,没指定动态数组的>大小,则使用默认大小10 */ protected Object[] elementData; /** * 元素个数 - elementCount 是动态数组的实际大小 */ protected int elementCount; /** * 容量增长 - 每次Vector容量增加时的增量值 - 如果在创建Vector时,指定了capacityIncrement的大小;则,每次当Vector中动态数组容量增加时>,增加的大小都是capacityIncrement */ protected int capacityIncrement; /** * Vector. 构造函数 * @param initialCapacity 容量大小 * @param capacityIncrement 扩容因子 */ public Vector(int initialCapacity, int capacityIncrement) { super(); if (initialCapacity < 0) throw new IllegalArgumentException("[Java-Core-Advanced]Illegal Capacity: "+initialCapacity); this.elementData = new Object[initialCapacity]; this.capacityIncrement = capacityIncrement; } /** * Vector. * @param initialCapacity 容量大小 */ public Vector(int initialCapacity) { this(initialCapacity, 0);//扩容因子为0 } /** * Vector. 默认为10 */ public Vector() { this(10); } /** * Vector. * @param c Collection */ public Vector(Collection<? extends E> c) { elementData = c.toArray(); elementCount = elementData.length; // c.toArray might (incorrectly) not return Object[] (see 6260652) if (elementData.getClass() != Object[].class) { elementData = Arrays.copyOf(elementData, elementCount, Object[].class); } } /** * @Description: copyInto * @param anArray void * @Autor: Jason */ public synchronized void copyInto(Object[] anArray) { System.arraycopy(elementData, 0, anArray, 0, elementCount); } /** * @Description: trimToSize * @Autor: Jason */ public synchronized void trimToSize() { modCount++; int oldCapacity = elementData.length; if (elementCount < oldCapacity) { elementData = Arrays.copyOf(elementData, elementCount); } } /** * @Description: ensureCapacity * @param minCapacity * @Autor: Jason */ public synchronized void ensureCapacity(int minCapacity) { if (minCapacity > 0) { modCount++; ensureCapacityHelper(minCapacity); } } /** * @Description: ensureCapacityHelper * @param minCapacity * @Autor: Jason */ private void ensureCapacityHelper(int minCapacity) { // overflow-conscious code if (minCapacity - elementData.length > 0) grow(minCapacity); } /** * 最大数组大小 */ private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; /** * @Description: grow * @param minCapacity * @Autor: Jason */ private void grow(int minCapacity) { // overflow-conscious code int oldCapacity = elementData.length; int newCapacity = oldCapacity + ((capacityIncrement > 0) ?capacityIncrement : oldCapacity); if (newCapacity - minCapacity < 0) newCapacity = minCapacity; if (newCapacity - MAX_ARRAY_SIZE > 0) newCapacity = hugeCapacity(minCapacity); elementData = Arrays.copyOf(elementData, newCapacity); } /** * @Description: hugeCapacity * @param minCapacity * @return int * @Autor: Jason */ private static int hugeCapacity(int minCapacity) { if (minCapacity < 0) // overflow throw new OutOfMemoryError(); return (minCapacity > MAX_ARRAY_SIZE) ? Integer.MAX_VALUE : MAX_ARRAY_SIZE; } /** * @Description: setSize * @param newSize void * @Autor: Jason */ public synchronized void setSize(int newSize) { modCount++; if (newSize > elementCount) { ensureCapacityHelper(newSize); } else { for (int i = newSize ; i < elementCount ; i++) { elementData[i] = null; } } elementCount = newSize; } /** * @Description: 返回当前容器的大小 * @return int * @Autor: Jason */ public synchronized int capacity() { return elementData.length; } /** * 返回当前数据统计 */ public synchronized int size() { return elementCount; } /** * 是否为空 */ public synchronized boolean isEmpty() { return elementCount == 0; } /** * @Description: 元素枚举 * @return Enumeration<E> * @Autor: Jason */ public Enumeration<E> elements() { return new Enumeration<E>() { int count = 0; public boolean hasMoreElements() { return count < elementCount; } public E nextElement() { synchronized (Vector.this) { if (count < elementCount) { return elementData(count++); } } throw new NoSuchElementException("Vector Enumeration"); } }; } /** * 是否包含 */ public boolean contains(Object o) { return indexOf(o, 0) >= 0; } /** * 元素的索引位置 */ public int indexOf(Object o) { return indexOf(o, 0); } /** * @Description: indexOf * @param o * @param index * @return int * @Autor: Jason */ public synchronized int indexOf(Object o, int index) { if (o == null) { for (int i = index ; i < elementCount ; i++) if (elementData[i]==null) return i; } else { for (int i = index ; i < elementCount ; i++) if (o.equals(elementData[i])) return i; } return -1; } /** * lastIndexOf */ public synchronized int lastIndexOf(Object o) { return lastIndexOf(o, elementCount-1); } /** * @Description: lastIndexOf * @param o * @param index * @return int * @Autor: Jason */ public synchronized int lastIndexOf(Object o, int index) { if (index >= elementCount) throw new IndexOutOfBoundsException(index + " >= "+ elementCount); if (o == null) { for (int i = index; i >= 0; i--) if (elementData[i]==null) return i; } else { for (int i = index; i >= 0; i--) if (o.equals(elementData[i])) return i; } return -1; } /** * @Description: elementAt * @param index * @return E * @Autor: Jason */ public synchronized E elementAt(int index) { if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); } return elementData(index); } /** * @Description: Returns the first component * @return E * @Autor: Jason */ public synchronized E firstElement() { if (elementCount == 0) { throw new NoSuchElementException(); } return elementData(0); } /** * @Description: 返回容器里最后一个元素 * @return E * @Autor: Jason */ public synchronized E lastElement() { if (elementCount == 0) { throw new NoSuchElementException(); } return elementData(elementCount - 1); } /** * @Description: 设置元素 * @param obj * @param index void * @Autor: Jason */ public synchronized void setElementAt(E obj, int index) { if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); } elementData[index] = obj; } /** * @Description: 移除指定位置的元素 * @param index 索引位置 * @Autor: Jason */ public synchronized void removeElementAt(int index) { modCount++; if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); } else if (index < 0) { throw new ArrayIndexOutOfBoundsException(index); } int j = elementCount - index - 1; if (j > 0) { System.arraycopy(elementData, index + 1, elementData, index, j); } elementCount--; elementData[elementCount] = null; /* to let gc do its work */ } /** * @Description: 插入数据到具体的索引位置 * @param obj * @param index 索引位置 * @Autor: Jason */ public synchronized void insertElementAt(E obj, int index) { modCount++; if (index > elementCount) { throw new ArrayIndexOutOfBoundsException(index + " > " + elementCount); } ensureCapacityHelper(elementCount + 1); System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); elementData[index] = obj; elementCount++; } /** * @Description: 添加元素 - Core 基本可以看出来Vector的数结构 * @param obj 元素 * @Autor: Jason */ public synchronized void addElement(E obj) { modCount++; ensureCapacityHelper(elementCount + 1); elementData[elementCount++] = obj; } /** * @Description: 移除指定Object元素的数据 * @param obj * @return boolean * @Autor: Jason */ public synchronized boolean removeElement(Object obj) { modCount++; int i = indexOf(obj); if (i >= 0) { removeElementAt(i); return true; } return false; } /** * @Description:移除所有的元素 * @Autor: Jason */ public synchronized void removeAllElements() { modCount++; // Let gc do its work for (int i = 0; i < elementCount; i++) elementData[i] = null; //循环置空 gc垃圾回收机制处理 elementCount = 0; } /** * 克隆接口 实现克隆 */ public synchronized Object clone() { try { @SuppressWarnings("unchecked") Vector<E> v = (Vector<E>) super.clone(); v.elementData = Arrays.copyOf(elementData, elementCount); v.modCount = 0; return v; } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable throw new InternalError(e); } } /** * toArray */ public synchronized Object[] toArray() { return Arrays.copyOf(elementData, elementCount); } /** * toArray */ @SuppressWarnings("unchecked") public synchronized <T> T[] toArray(T[] a) { if (a.length < elementCount) return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); System.arraycopy(elementData, 0, a, 0, elementCount); if (a.length > elementCount) { a[elementCount] = null; } return a; } // Positional Access Operations /** * @Description: elementData * @param index * @return E * @Autor: Jason */ @SuppressWarnings("unchecked") E elementData(int index) { return (E) elementData[index]; } /** * get by Index */ public synchronized E get(int index) { if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index); return elementData(index); } /** * set data into Index Vector */ public synchronized E set(int index, E element) { if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index); E oldValue = elementData(index); elementData[index] = element; return oldValue; } /** * 添加数据到后面 */ public synchronized boolean add(E e) { modCount++; ensureCapacityHelper(elementCount + 1); elementData[elementCount++] = e; return true; } /** * 移除元素 */ public boolean remove(Object o) { return removeElement(o); } /** * 添加元素 */ public void add(int index, E element) { insertElementAt(element, index); } /** * 移除置空 垃圾回收机制做处理 */ public synchronized E remove(int index) { modCount++; if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index); E oldValue = elementData(index); int numMoved = elementCount - index - 1; if (numMoved > 0) System.arraycopy(elementData, index+1, elementData, index,numMoved); elementData[--elementCount] = null; // Let gc do its work return oldValue; } /** * 清空 */ public void clear() { removeAllElements(); } // Bulk Operations /** * Collection 循环比较所有是不是 contains(e) */ public synchronized boolean containsAll(Collection<?> c) { return super.containsAll(c); } /** * 添加整个集合 */ public synchronized boolean addAll(Collection<? extends E> c) { modCount++; Object[] a = c.toArray(); int numNew = a.length; ensureCapacityHelper(elementCount + numNew); System.arraycopy(a, 0, elementData, elementCount, numNew); elementCount += numNew; return numNew != 0; } /** * 移除所有 */ public synchronized boolean removeAll(Collection<?> c) { return super.removeAll(c); } /** * retainAll 包含所有 */ public synchronized boolean retainAll(Collection<?> c) { return super.retainAll(c); } /** * addAll Collection */ public synchronized boolean addAll(int index, Collection<? extends E> c) { modCount++; if (index < 0 || index > elementCount) {//索引越界异常 throw new ArrayIndexOutOfBoundsException(index); } Object[] a = c.toArray(); int numNew = a.length; ensureCapacityHelper(elementCount + numNew); int numMoved = elementCount - index; if (numMoved > 0) System.arraycopy(elementData, index, elementData, index + numNew,numMoved); System.arraycopy(a, 0, elementData, index, numNew); elementCount += numNew; return numNew != 0; } /** * equals */ public synchronized boolean equals(Object o) { return super.equals(o); } /** * hashCode = 31*hashCode + (e==null ? 0 : e.hashCode()); 抽象类的HashCode方法 没有重写 */ public synchronized int hashCode() { return super.hashCode(); } /** * 抽象集合的toString方法 */ public synchronized String toString() { return super.toString(); } /** * Returns a view of the portion of this List between fromIndex, * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are * equal, the returned List is empty.) The returned List is backed by this * List, so changes in the returned List are reflected in this List, and * vice-versa. The returned List supports all of the optional List * operations supported by this List. * * <p>This method eliminates the need for explicit range operations (of * the sort that commonly exist for arrays). Any operation that expects * a List can be used as a range operation by operating on a subList view * instead of a whole List. For example, the following idiom * removes a range of elements from a List: * <pre> * list.subList(from, to).clear(); * </pre> * Similar idioms may be constructed for indexOf and lastIndexOf, * and all of the algorithms in the Collections class can be applied to * a subList. * * <p>The semantics of the List returned by this method become undefined if * the backing list (i.e., this List) is <i>structurally modified</i> in * any way other than via the returned List. (Structural modifications are * those that change the size of the List, or otherwise perturb it in such * a fashion that iterations in progress may yield incorrect results.) * * @param fromIndex low endpoint (inclusive) of the subList * @param toIndex high endpoint (exclusive) of the subList * @return a view of the specified range within this List * @throws IndexOutOfBoundsException if an endpoint index value is out of range * {@code (fromIndex < 0 || toIndex > size)} * @throws IllegalArgumentException if the endpoint indices are out of order * {@code (fromIndex > toIndex)} */ /*public synchronized List<E> subList(int fromIndex, int toIndex) { return Collections.synchronizedList(super.subList(fromIndex, toIndex),this); }*/ /** * 移除范围 */ protected synchronized void removeRange(int fromIndex, int toIndex) { modCount++; int numMoved = elementCount - toIndex; System.arraycopy(elementData, toIndex, elementData, fromIndex,numMoved); // Let gc do its work int newElementCount = elementCount - (toIndex-fromIndex); while (elementCount != newElementCount) elementData[--elementCount] = null; } /** * Save the state of the {@code Vector} instance to a stream (that * is, serialize it). * This method performs synchronization to ensure the consistency * of the serialized data. */ /** * @Description: writeObject * @param s * @throws java.io.IOException * @Autor: Jason */ private void writeObject(java.io.ObjectOutputStream s)throws java.io.IOException { final java.io.ObjectOutputStream.PutField fields = s.putFields(); final Object[] data; synchronized (this) { fields.put("capacityIncrement", capacityIncrement); fields.put("elementCount", elementCount); data = elementData.clone(); } fields.put("elementData", data); s.writeFields(); } /** * List 迭代器 */ public synchronized ListIterator<E> listIterator(int index) { if (index < 0 || index > elementCount) throw new IndexOutOfBoundsException("Index: "+index); return new ListItr(index); } /** * Returns a list iterator over the elements in this list (in proper sequence). */ public synchronized ListIterator<E> listIterator() { return new ListItr(0); } /** * Returns an iterator over the elements in this list in proper sequence. */ public synchronized Iterator<E> iterator() { return new Itr(); } /** * @Package:cn.ucaner.sourceanalysis * @ClassName:Itr * @Description: <p> An optimized version of AbstractList.Itr 实现迭代器</p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ private class Itr implements Iterator<E> { int cursor; // index of next element to return int lastRet = -1; // index of last element returned; -1 if no such int expectedModCount = modCount; public boolean hasNext() { // Racy but within spec, since modifications are checked // within or after synchronization in next/previous return cursor != elementCount; } public E next() { synchronized (Vector.this) { checkForComodification(); int i = cursor; if (i >= elementCount) throw new NoSuchElementException(); cursor = i + 1; return elementData(lastRet = i); } } public void remove() { if (lastRet == -1) throw new IllegalStateException(); synchronized (Vector.this) { checkForComodification(); Vector.this.remove(lastRet); expectedModCount = modCount; } cursor = lastRet; lastRet = -1; } @Override public void forEachRemaining(Consumer<? super E> action) { Objects.requireNonNull(action); synchronized (Vector.this) { final int size = elementCount; int i = cursor; if (i >= size) { return; } @SuppressWarnings("unchecked") final E[] elementData = (E[]) Vector.this.elementData; if (i >= elementData.length) { throw new ConcurrentModificationException(); } while (i != size && modCount == expectedModCount) { action.accept(elementData[i++]); } // update once at end of iteration to reduce heap write traffic cursor = i; lastRet = i - 1; checkForComodification(); } } final void checkForComodification() { if (modCount != expectedModCount) throw new ConcurrentModificationException(); } } /** * @Package:cn.ucaner.sourceanalysis * @ClassName:ListItr * @Description: <p> An optimized version of AbstractList.ListItr </p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ final class ListItr extends Itr implements ListIterator<E> { ListItr(int index) { super(); cursor = index; } public boolean hasPrevious() { return cursor != 0; } public int nextIndex() { return cursor; } public int previousIndex() { return cursor - 1; } public E previous() { synchronized (Vector.this) { checkForComodification(); int i = cursor - 1; if (i < 0) throw new NoSuchElementException(); cursor = i; return elementData(lastRet = i); } } public void set(E e) { if (lastRet == -1) throw new IllegalStateException(); synchronized (Vector.this) { checkForComodification(); Vector.this.set(lastRet, e); } } public void add(E e) { int i = cursor; synchronized (Vector.this) { checkForComodification(); Vector.this.add(i, e); expectedModCount = modCount; } cursor = i + 1; lastRet = -1; } } /** * forEach 增强for循环 */ @Override public synchronized void forEach(Consumer<? super E> action) { Objects.requireNonNull(action); final int expectedModCount = modCount; @SuppressWarnings("unchecked") final E[] elementData = (E[]) this.elementData; final int elementCount = this.elementCount; for (int i=0; modCount == expectedModCount && i < elementCount; i++) { action.accept(elementData[i]); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } } /** * removeIf */ @Override @SuppressWarnings("unchecked") public synchronized boolean removeIf(Predicate<? super E> filter) { Objects.requireNonNull(filter); // figure out which elements are to be removed // any exception thrown from the filter predicate at this stage // will leave the collection unmodified int removeCount = 0; final int size = elementCount; final BitSet removeSet = new BitSet(size); final int expectedModCount = modCount; for (int i=0; modCount == expectedModCount && i < size; i++) { final E element = (E) elementData[i]; if (filter.test(element)) { removeSet.set(i); removeCount++; } } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } // shift surviving elements left over the spaces left by removed elements final boolean anyToRemove = removeCount > 0; if (anyToRemove) { final int newSize = size - removeCount; for (int i=0, j=0; (i < size) && (j < newSize); i++, j++) { i = removeSet.nextClearBit(i); elementData[j] = elementData[i]; } for (int k=newSize; k < size; k++) { elementData[k] = null; // Let gc do its work } elementCount = newSize; if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; } return anyToRemove; } /** * 替换 */ @Override @SuppressWarnings("unchecked") public synchronized void replaceAll(UnaryOperator<E> operator) { Objects.requireNonNull(operator); final int expectedModCount = modCount; final int size = elementCount; for (int i=0; modCount == expectedModCount && i < size; i++) { elementData[i] = operator.apply((E) elementData[i]); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; } /** * 排序 */ @SuppressWarnings("unchecked") @Override public synchronized void sort(Comparator<? super E> c) { final int expectedModCount = modCount; Arrays.sort((E[]) elementData, 0, elementCount, c); if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; } /** * 分隔符 */ @Override public Spliterator<E> spliterator() { return new VectorSpliterator<>(this, null, 0, -1, 0); } /** * @Package:cn.ucaner.sourceanalysis * @ClassName:VectorSpliterator * @Description: <p> Similar to ArrayList Spliterator </p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ static final class VectorSpliterator<E> implements Spliterator<E> { private final Vector<E> list; private Object[] array; private int index; // current index, modified on advance/split private int fence; // -1 until used; then one past last index private int expectedModCount; // initialized when fence set /** * VectorSpliterator. Create new spliterator covering the given range * @param list * @param array * @param origin * @param fence * @param expectedModCount */ VectorSpliterator(Vector<E> list, Object[] array, int origin, int fence, int expectedModCount) { this.list = list; this.array = array; this.index = origin; this.fence = fence; this.expectedModCount = expectedModCount; } private int getFence() { // initialize on first use int hi; if ((hi = fence) < 0) { synchronized(list) { array = list.elementData; expectedModCount = list.modCount; hi = fence = list.elementCount; } } return hi; } public Spliterator<E> trySplit() { int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; return (lo >= mid) ? null : new VectorSpliterator<E>(list, array, lo, index = mid, expectedModCount); } @SuppressWarnings("unchecked") public boolean tryAdvance(Consumer<? super E> action) { int i; if (action == null) throw new NullPointerException(); if (getFence() > (i = index)) { index = i + 1; action.accept((E)array[i]); if (list.modCount != expectedModCount) throw new ConcurrentModificationException(); return true; } return false; } @SuppressWarnings("unchecked") public void forEachRemaining(Consumer<? super E> action) { int i, hi; // hoist accesses and checks from loop Vector<E> lst; Object[] a; if (action == null) throw new NullPointerException(); if ((lst = list) != null) { if ((hi = fence) < 0) { synchronized(lst) { expectedModCount = lst.modCount; a = array = lst.elementData; hi = fence = lst.elementCount; } } else a = array; if (a != null && (i = index) >= 0 && (index = hi) <= a.length) { while (i < hi) action.accept((E) a[i++]); if (lst.modCount == expectedModCount) return; } } throw new ConcurrentModificationException(); } public long estimateSize() { return (long) (getFence() - index); } public int characteristics() { return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; } } }
/** * <html> * <body> * <P> Copyright JasonInternational</p> * <p> All rights reserved.</p> * <p> Created on 2018年6月29日 上午9:00:48</p> * <p> Created by Jason </p> * </body> * </html> */package cn.ucaner.sourceanalysis.list;
import java.util.AbstractList;import java.util.Arrays;import java.util.BitSet;import java.util.Collection;import java.util.Comparator;import java.util.ConcurrentModificationException;import java.util.Enumeration;import java.util.Iterator;import java.util.List;import java.util.ListIterator;import java.util.NoSuchElementException;import java.util.Objects;import java.util.RandomAccess;import java.util.Spliterator;import java.util.function.Consumer;import java.util.function.Predicate;import java.util.function.UnaryOperator;
/** * @Package:cn.ucaner.sourceanalysis * @ClassName:Vector * @Description: <p> Vector Vector 可实现自动增长的对象数组</p>* @Author: - Jason * @CreatTime:2018年6月29日 上午9:00:48 * @Modify By: * @ModifyTime: 2018年6月29日* @Modify marker: * @version V1.0*/
/****************Notice******************[参考]{@link https://www.cnblogs.com/zheting/p/7708366.html} {@link https://www.cnblogs.com/skywang12345/p/3308833.html}
Vector 是矢量队列,它是JDK1.0版本添加的类。继承于AbstractList,实现了List, RandomAccess, Cloneable这些接口
Vector 继承了AbstractList,实现了List;所以,它是一个队列,支持相关的添加、删除、修改、遍历等功能.Vector 实现了RandmoAccess接口,即提供了随机访问功能.RandmoAccess是Java中用来被List实现,为List提供快速访问功能的.在Vector中,我们即可以通过元素的序号快速获取元素对象;这就是快速随机访问。
Vector 实现了Cloneable接口,即实现clone()函数,它能被克隆,与ArrayList不同,Vector中的操作是线程安全的.
Vector共有4个构造函数Vector()// 默认构造函数Vector(int capacity)// capacity是Vector的默认容量大小。当由于增加数据导致容量增加时,每次容量会增加一倍。Vector(int capacity, int capacityIncrement)// capacity是Vector的默认容量大小,capacityIncrement是每次Vector容量增加时的增量值。Vector(Collection<? extends E> collection)// 创建一个包含collection的Vector
*******************End**************************/public class Vector<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, java.io.Serializable{
private static final long serialVersionUID = 2411957469099220630L;/** * 元素数据 - elementData是个动态数组,如果初始化Vector时,没指定动态数组的>大小,则使用默认大小10 */protected Object[] elementData;/** * 元素个数 - elementCount 是动态数组的实际大小 */protected int elementCount;
/** * 容量增长 - 每次Vector容量增加时的增量值 - 如果在创建Vector时,指定了capacityIncrement的大小;则,每次当Vector中动态数组容量增加时>,增加的大小都是capacityIncrement */protected int capacityIncrement;/*** Vector. 构造函数* @param initialCapacity 容量大小* @param capacityIncrement 扩容因子 */public Vector(int initialCapacity, int capacityIncrement) { super(); if (initialCapacity < 0) throw new IllegalArgumentException("[Java-Core-Advanced]Illegal Capacity: "+initialCapacity); this.elementData = new Object[initialCapacity]; this.capacityIncrement = capacityIncrement; }/*** Vector. * @param initialCapacity 容量大小 */public Vector(int initialCapacity) { this(initialCapacity, 0);//扩容因子为0 }/*** Vector. 默认为10 */public Vector() { this(10); }/*** Vector. * @param c Collection */public Vector(Collection<? extends E> c) { elementData = c.toArray(); elementCount = elementData.length; // c.toArray might (incorrectly) not return Object[] (see 6260652) if (elementData.getClass() != Object[].class) { elementData = Arrays.copyOf(elementData, elementCount, Object[].class); } }/** * @Description: copyInto * @param anArray void * @Autor: Jason */public synchronized void copyInto(Object[] anArray) { System.arraycopy(elementData, 0, anArray, 0, elementCount); }/** * @Description: trimToSize * @Autor: Jason */public synchronized void trimToSize() { modCount++; int oldCapacity = elementData.length; if (elementCount < oldCapacity) { elementData = Arrays.copyOf(elementData, elementCount); } }/** * @Description: ensureCapacity * @param minCapacity * @Autor: Jason */public synchronized void ensureCapacity(int minCapacity) { if (minCapacity > 0) { modCount++; ensureCapacityHelper(minCapacity); } }/** * @Description: ensureCapacityHelper * @param minCapacity * @Autor: Jason */private void ensureCapacityHelper(int minCapacity) { // overflow-conscious code if (minCapacity - elementData.length > 0) grow(minCapacity); }
/** * 最大数组大小 */ private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
/** * @Description: grow * @param minCapacity * @Autor: Jason */private void grow(int minCapacity) {// overflow-conscious codeint oldCapacity = elementData.length;int newCapacity = oldCapacity + ((capacityIncrement > 0) ?capacityIncrement : oldCapacity);if (newCapacity - minCapacity < 0) newCapacity = minCapacity;if (newCapacity - MAX_ARRAY_SIZE > 0) newCapacity = hugeCapacity(minCapacity);elementData = Arrays.copyOf(elementData, newCapacity);}
/** * @Description: hugeCapacity * @param minCapacity * @return int * @Autor: Jason */private static int hugeCapacity(int minCapacity) { if (minCapacity < 0) // overflow throw new OutOfMemoryError(); return (minCapacity > MAX_ARRAY_SIZE) ? Integer.MAX_VALUE : MAX_ARRAY_SIZE;}
/** * @Description: setSize * @param newSize void * @Autor: Jason */public synchronized void setSize(int newSize) { modCount++; if (newSize > elementCount) { ensureCapacityHelper(newSize); } else { for (int i = newSize ; i < elementCount ; i++) { elementData[i] = null; } } elementCount = newSize;}
/** * @Description: 返回当前容器的大小 * @return int * @Autor: Jason */ public synchronized int capacity() { return elementData.length; }
/** * 返回当前数据统计 */ public synchronized int size() { return elementCount; }
/** * 是否为空 */public synchronized boolean isEmpty() { return elementCount == 0;}
/** * @Description: 元素枚举 * @return Enumeration<E> * @Autor: Jason */public Enumeration<E> elements() { return new Enumeration<E>() { int count = 0; public boolean hasMoreElements() { return count < elementCount; } public E nextElement() { synchronized (Vector.this) { if (count < elementCount) { return elementData(count++); } } throw new NoSuchElementException("Vector Enumeration"); } };}
/** * 是否包含 */public boolean contains(Object o) { return indexOf(o, 0) >= 0;}
/** * 元素的索引位置 */ public int indexOf(Object o) { return indexOf(o, 0); }
/** * @Description: indexOf * @param o * @param index * @return int * @Autor: Jason */public synchronized int indexOf(Object o, int index) { if (o == null) { for (int i = index ; i < elementCount ; i++) if (elementData[i]==null) return i; } else { for (int i = index ; i < elementCount ; i++) if (o.equals(elementData[i])) return i; } return -1;}
/** * lastIndexOf */ public synchronized int lastIndexOf(Object o) { return lastIndexOf(o, elementCount-1); }
/** * @Description: lastIndexOf * @param o * @param index * @return int * @Autor: Jason */ public synchronized int lastIndexOf(Object o, int index) { if (index >= elementCount) throw new IndexOutOfBoundsException(index + " >= "+ elementCount);
if (o == null) { for (int i = index; i >= 0; i--) if (elementData[i]==null) return i; } else { for (int i = index; i >= 0; i--) if (o.equals(elementData[i])) return i; } return -1; }
/** * @Description: elementAt * @param index * @return E * @Autor: Jason */ public synchronized E elementAt(int index) { if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); }
return elementData(index); }
/** * @Description: Returns the first component * @return E * @Autor: Jason */public synchronized E firstElement() { if (elementCount == 0) { throw new NoSuchElementException(); } return elementData(0);}
/** * @Description: 返回容器里最后一个元素 * @return E * @Autor: Jason */ public synchronized E lastElement() { if (elementCount == 0) { throw new NoSuchElementException(); } return elementData(elementCount - 1); }
/** * @Description: 设置元素 * @param obj * @param index void * @Autor: Jason */ public synchronized void setElementAt(E obj, int index) { if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); } elementData[index] = obj; }
/** * @Description: 移除指定位置的元素 * @param index 索引位置 * @Autor: Jason */ public synchronized void removeElementAt(int index) { modCount++; if (index >= elementCount) { throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); } else if (index < 0) { throw new ArrayIndexOutOfBoundsException(index); } int j = elementCount - index - 1; if (j > 0) { System.arraycopy(elementData, index + 1, elementData, index, j); } elementCount--; elementData[elementCount] = null; /* to let gc do its work */ }
/** * @Description: 插入数据到具体的索引位置 * @param obj * @param index 索引位置 * @Autor: Jason */ public synchronized void insertElementAt(E obj, int index) { modCount++; if (index > elementCount) { throw new ArrayIndexOutOfBoundsException(index + " > " + elementCount); } ensureCapacityHelper(elementCount + 1); System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); elementData[index] = obj; elementCount++; }
/** * @Description: 添加元素 - Core 基本可以看出来Vector的数结构 * @param obj 元素 * @Autor: Jason */ public synchronized void addElement(E obj) { modCount++; ensureCapacityHelper(elementCount + 1); elementData[elementCount++] = obj; }
/** * @Description: 移除指定Object元素的数据 * @param obj * @return boolean * @Autor: Jason */public synchronized boolean removeElement(Object obj) { modCount++; int i = indexOf(obj); if (i >= 0) { removeElementAt(i); return true; } return false;}
/** * @Description:移除所有的元素 * @Autor: Jason */public synchronized void removeAllElements() { modCount++; // Let gc do its work for (int i = 0; i < elementCount; i++) elementData[i] = null; //循环置空 gc垃圾回收机制处理 elementCount = 0;}
/** * 克隆接口 实现克隆 */ public synchronized Object clone() { try { @SuppressWarnings("unchecked") Vector<E> v = (Vector<E>) super.clone(); v.elementData = Arrays.copyOf(elementData, elementCount); v.modCount = 0; return v; } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable throw new InternalError(e); } }
/** * toArray */ public synchronized Object[] toArray() { return Arrays.copyOf(elementData, elementCount); }
/** * toArray */@SuppressWarnings("unchecked")public synchronized <T> T[] toArray(T[] a) { if (a.length < elementCount) return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); System.arraycopy(elementData, 0, a, 0, elementCount); if (a.length > elementCount) { a[elementCount] = null; } return a;}
// Positional Access Operations/** * @Description: elementData * @param index * @return E * @Autor: Jason */ @SuppressWarnings("unchecked") E elementData(int index) { return (E) elementData[index]; }
/** * get by Index */ public synchronized E get(int index) { if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index); return elementData(index); }
/** * set data into Index Vector */ public synchronized E set(int index, E element) { if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index);
E oldValue = elementData(index); elementData[index] = element; return oldValue; } /** * 添加数据到后面 */ public synchronized boolean add(E e) { modCount++; ensureCapacityHelper(elementCount + 1); elementData[elementCount++] = e; return true; }
/** * 移除元素 */ public boolean remove(Object o) { return removeElement(o); }
/** * 添加元素 */ public void add(int index, E element) { insertElementAt(element, index); }
/** * 移除置空 垃圾回收机制做处理 */ public synchronized E remove(int index) { modCount++; if (index >= elementCount) throw new ArrayIndexOutOfBoundsException(index); E oldValue = elementData(index);
int numMoved = elementCount - index - 1; if (numMoved > 0) System.arraycopy(elementData, index+1, elementData, index,numMoved); elementData[--elementCount] = null; // Let gc do its work
return oldValue; }
/** * 清空 */ public void clear() { removeAllElements(); }
// Bulk Operations /** * Collection 循环比较所有是不是 contains(e) */ public synchronized boolean containsAll(Collection<?> c) { return super.containsAll(c); }
/** * 添加整个集合 */ public synchronized boolean addAll(Collection<? extends E> c) { modCount++; Object[] a = c.toArray(); int numNew = a.length; ensureCapacityHelper(elementCount + numNew); System.arraycopy(a, 0, elementData, elementCount, numNew); elementCount += numNew; return numNew != 0; }
/** * 移除所有 */ public synchronized boolean removeAll(Collection<?> c) { return super.removeAll(c); }
/** * retainAll 包含所有 */ public synchronized boolean retainAll(Collection<?> c) { return super.retainAll(c); }
/** * addAll Collection */ public synchronized boolean addAll(int index, Collection<? extends E> c) { modCount++; if (index < 0 || index > elementCount) {//索引越界异常 throw new ArrayIndexOutOfBoundsException(index); } Object[] a = c.toArray(); int numNew = a.length; ensureCapacityHelper(elementCount + numNew); int numMoved = elementCount - index; if (numMoved > 0) System.arraycopy(elementData, index, elementData, index + numNew,numMoved);
System.arraycopy(a, 0, elementData, index, numNew); elementCount += numNew; return numNew != 0; }
/** * equals */ public synchronized boolean equals(Object o) { return super.equals(o); }
/** * hashCode = 31*hashCode + (e==null ? 0 : e.hashCode()); 抽象类的HashCode方法 没有重写 */ public synchronized int hashCode() { return super.hashCode(); }
/** * 抽象集合的toString方法 */ public synchronized String toString() { return super.toString(); }
/** * Returns a view of the portion of this List between fromIndex, * inclusive, and toIndex, exclusive. (If fromIndex and toIndex are * equal, the returned List is empty.) The returned List is backed by this * List, so changes in the returned List are reflected in this List, and * vice-versa. The returned List supports all of the optional List * operations supported by this List. * * <p>This method eliminates the need for explicit range operations (of * the sort that commonly exist for arrays). Any operation that expects * a List can be used as a range operation by operating on a subList view * instead of a whole List. For example, the following idiom * removes a range of elements from a List: * <pre> * list.subList(from, to).clear(); * </pre> * Similar idioms may be constructed for indexOf and lastIndexOf, * and all of the algorithms in the Collections class can be applied to * a subList. * * <p>The semantics of the List returned by this method become undefined if * the backing list (i.e., this List) is <i>structurally modified</i> in * any way other than via the returned List. (Structural modifications are * those that change the size of the List, or otherwise perturb it in such * a fashion that iterations in progress may yield incorrect results.) * * @param fromIndex low endpoint (inclusive) of the subList * @param toIndex high endpoint (exclusive) of the subList * @return a view of the specified range within this List * @throws IndexOutOfBoundsException if an endpoint index value is out of range * {@code (fromIndex < 0 || toIndex > size)} * @throws IllegalArgumentException if the endpoint indices are out of order * {@code (fromIndex > toIndex)} */ /*public synchronized List<E> subList(int fromIndex, int toIndex) { return Collections.synchronizedList(super.subList(fromIndex, toIndex),this); }*/
/** * 移除范围 */ protected synchronized void removeRange(int fromIndex, int toIndex) { modCount++; int numMoved = elementCount - toIndex; System.arraycopy(elementData, toIndex, elementData, fromIndex,numMoved); // Let gc do its work int newElementCount = elementCount - (toIndex-fromIndex); while (elementCount != newElementCount) elementData[--elementCount] = null; }
/** * Save the state of the {@code Vector} instance to a stream (that * is, serialize it). * This method performs synchronization to ensure the consistency * of the serialized data. */ /** * @Description: writeObject * @param s * @throws java.io.IOException * @Autor: Jason */ private void writeObject(java.io.ObjectOutputStream s)throws java.io.IOException { final java.io.ObjectOutputStream.PutField fields = s.putFields(); final Object[] data; synchronized (this) { fields.put("capacityIncrement", capacityIncrement); fields.put("elementCount", elementCount); data = elementData.clone(); } fields.put("elementData", data); s.writeFields(); }
/** * List 迭代器 */ public synchronized ListIterator<E> listIterator(int index) { if (index < 0 || index > elementCount) throw new IndexOutOfBoundsException("Index: "+index); return new ListItr(index); }
/** * Returns a list iterator over the elements in this list (in proper sequence). */ public synchronized ListIterator<E> listIterator() { return new ListItr(0); }
/** * Returns an iterator over the elements in this list in proper sequence. */ public synchronized Iterator<E> iterator() { return new Itr(); }
/** * @Package:cn.ucaner.sourceanalysis * @ClassName:Itr * @Description: <p> An optimized version of AbstractList.Itr 实现迭代器</p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ private class Itr implements Iterator<E> { int cursor; // index of next element to return int lastRet = -1; // index of last element returned; -1 if no such int expectedModCount = modCount;
public boolean hasNext() { // Racy but within spec, since modifications are checked // within or after synchronization in next/previous return cursor != elementCount; }
public E next() { synchronized (Vector.this) { checkForComodification(); int i = cursor; if (i >= elementCount) throw new NoSuchElementException(); cursor = i + 1; return elementData(lastRet = i); } }
public void remove() { if (lastRet == -1) throw new IllegalStateException(); synchronized (Vector.this) { checkForComodification(); Vector.this.remove(lastRet); expectedModCount = modCount; } cursor = lastRet; lastRet = -1; }
@Override public void forEachRemaining(Consumer<? super E> action) { Objects.requireNonNull(action); synchronized (Vector.this) { final int size = elementCount; int i = cursor; if (i >= size) { return; } @SuppressWarnings("unchecked") final E[] elementData = (E[]) Vector.this.elementData; if (i >= elementData.length) { throw new ConcurrentModificationException(); } while (i != size && modCount == expectedModCount) { action.accept(elementData[i++]); } // update once at end of iteration to reduce heap write traffic cursor = i; lastRet = i - 1; checkForComodification(); } }
final void checkForComodification() { if (modCount != expectedModCount) throw new ConcurrentModificationException(); } }
/** * @Package:cn.ucaner.sourceanalysis * @ClassName:ListItr * @Description: <p> An optimized version of AbstractList.ListItr </p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ final class ListItr extends Itr implements ListIterator<E> { ListItr(int index) { super(); cursor = index; }
public boolean hasPrevious() { return cursor != 0; }
public int nextIndex() { return cursor; }
public int previousIndex() { return cursor - 1; }
public E previous() { synchronized (Vector.this) { checkForComodification(); int i = cursor - 1; if (i < 0) throw new NoSuchElementException(); cursor = i; return elementData(lastRet = i); } }
public void set(E e) { if (lastRet == -1) throw new IllegalStateException(); synchronized (Vector.this) { checkForComodification(); Vector.this.set(lastRet, e); } }
public void add(E e) { int i = cursor; synchronized (Vector.this) { checkForComodification(); Vector.this.add(i, e); expectedModCount = modCount; } cursor = i + 1; lastRet = -1; } }
/** * forEach 增强for循环 */ @Override public synchronized void forEach(Consumer<? super E> action) { Objects.requireNonNull(action); final int expectedModCount = modCount; @SuppressWarnings("unchecked") final E[] elementData = (E[]) this.elementData; final int elementCount = this.elementCount; for (int i=0; modCount == expectedModCount && i < elementCount; i++) { action.accept(elementData[i]); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } }
/** * removeIf */ @Override @SuppressWarnings("unchecked") public synchronized boolean removeIf(Predicate<? super E> filter) { Objects.requireNonNull(filter); // figure out which elements are to be removed // any exception thrown from the filter predicate at this stage // will leave the collection unmodified int removeCount = 0; final int size = elementCount; final BitSet removeSet = new BitSet(size); final int expectedModCount = modCount; for (int i=0; modCount == expectedModCount && i < size; i++) { final E element = (E) elementData[i]; if (filter.test(element)) { removeSet.set(i); removeCount++; } } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); }
// shift surviving elements left over the spaces left by removed elements final boolean anyToRemove = removeCount > 0; if (anyToRemove) { final int newSize = size - removeCount; for (int i=0, j=0; (i < size) && (j < newSize); i++, j++) { i = removeSet.nextClearBit(i); elementData[j] = elementData[i]; } for (int k=newSize; k < size; k++) { elementData[k] = null; // Let gc do its work } elementCount = newSize; if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; }
return anyToRemove; }
/** * 替换 */ @Override @SuppressWarnings("unchecked") public synchronized void replaceAll(UnaryOperator<E> operator) { Objects.requireNonNull(operator); final int expectedModCount = modCount; final int size = elementCount; for (int i=0; modCount == expectedModCount && i < size; i++) { elementData[i] = operator.apply((E) elementData[i]); } if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; }
/** * 排序 */ @SuppressWarnings("unchecked") @Override public synchronized void sort(Comparator<? super E> c) { final int expectedModCount = modCount; Arrays.sort((E[]) elementData, 0, elementCount, c); if (modCount != expectedModCount) { throw new ConcurrentModificationException(); } modCount++; }
/** * 分隔符 */ @Override public Spliterator<E> spliterator() { return new VectorSpliterator<>(this, null, 0, -1, 0); }
/** * @Package:cn.ucaner.sourceanalysis * @ClassName:VectorSpliterator * @Description: <p> Similar to ArrayList Spliterator </p> * @Author: - Jason * @Modify By: * @Modify marker: * @version V1.0 */ static final class VectorSpliterator<E> implements Spliterator<E> { private final Vector<E> list; private Object[] array; private int index; // current index, modified on advance/split private int fence; // -1 until used; then one past last index private int expectedModCount; // initialized when fence set
/** * VectorSpliterator. Create new spliterator covering the given range * @param list * @param array * @param origin * @param fence * @param expectedModCount */ VectorSpliterator(Vector<E> list, Object[] array, int origin, int fence, int expectedModCount) { this.list = list; this.array = array; this.index = origin; this.fence = fence; this.expectedModCount = expectedModCount; }
private int getFence() { // initialize on first use int hi; if ((hi = fence) < 0) { synchronized(list) { array = list.elementData; expectedModCount = list.modCount; hi = fence = list.elementCount; } } return hi; }
public Spliterator<E> trySplit() { int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; return (lo >= mid) ? null : new VectorSpliterator<E>(list, array, lo, index = mid, expectedModCount); }
@SuppressWarnings("unchecked") public boolean tryAdvance(Consumer<? super E> action) { int i; if (action == null) throw new NullPointerException(); if (getFence() > (i = index)) { index = i + 1; action.accept((E)array[i]); if (list.modCount != expectedModCount) throw new ConcurrentModificationException(); return true; } return false; }
@SuppressWarnings("unchecked") public void forEachRemaining(Consumer<? super E> action) { int i, hi; // hoist accesses and checks from loop Vector<E> lst; Object[] a; if (action == null) throw new NullPointerException(); if ((lst = list) != null) { if ((hi = fence) < 0) { synchronized(lst) { expectedModCount = lst.modCount; a = array = lst.elementData; hi = fence = lst.elementCount; } } else a = array; if (a != null && (i = index) >= 0 && (index = hi) <= a.length) { while (i < hi) action.accept((E) a[i++]); if (lst.modCount == expectedModCount) return; } } throw new ConcurrentModificationException(); }
public long estimateSize() { return (long) (getFence() - index); }
public int characteristics() { return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; } }}