Simple object pool : Auto Growth Array « Collections Data Structure « Java

Simple object pool

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 *  distributed under the License is distributed on an "AS IS" BASIS,
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 * Simple object pool. Based on ThreadPool and few other classes
 * The pool will ignore overflow and return null if empty.
 * @author Gal Shachor
 * @author Costin Manolache
public final class SimplePool {
   * Where the threads are held.
  private Object pool[];

  private int max;

  private int last;

  private int current = -1;

  private Object lock;

  public static final int DEFAULT_SIZE = 32;

  static final int debug = 0;

  public SimplePool() {

  public SimplePool(int size) {
    this(size, size);

  public SimplePool(int size, int max) {
    this.max = max;
    pool = new Object[size];
    this.last = size - 1;
    lock = new Object();

  public void set(Object o) {

   * Add the object to the pool, silent nothing if the pool is full
  public void put(Object o) {
    synchronized (lock) {
      if (current < last) {
        pool[current] = o;
      } else if (current < max) {
        // realocate
        int newSize = pool.length * 2;
        if (newSize > max)
          newSize = max + 1;
        Object tmp[] = new Object[newSize];
        last = newSize - 1;
        System.arraycopy(pool, 0, tmp, 0, pool.length);
        pool = tmp;
        pool[current] = o;

   * Get an object from the pool, null if the pool is empty.
  public Object get() {
    Object item = null;
    synchronized (lock) {
      if (current >= 0) {
        item = pool[current];
        pool[current] = null;
        current -= 1;
    return item;

   * Return the size of the pool
  public int getMax() {
    return max;

   * Number of object in the pool
  public int getCount() {
    return current + 1;

  public void shutdown() {



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