Create a Byte Array List in Java

/*from ww  w. j  av  a 2 s . co  m*/
// Copyright (c) 2003-2009, Jodd Team (jodd.org). All Rights Reserved.


import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.io.IOException;

/**
 * ArrayList of byte primitives.
 */
public class ByteArrayList implements Serializable {

  private byte[] array;
  private int size;

  public static int initialCapacity = 10;

  /**
   * Constructs an empty list with an initial capacity.
   */
  public ByteArrayList() {
    this(initialCapacity);
  }

  /**
   * Constructs an empty list with the specified initial capacity.
   */
  public ByteArrayList(int initialCapacity) {
    if (initialCapacity < 0) {
      throw new IllegalArgumentException("Capacity can't be negative: " + initialCapacity);
    }
    array = new byte[initialCapacity];
    size = 0;
  }

  /**
   * Constructs a list containing the elements of the specified array.
   * The list instance has an initial capacity of 110% the size of the specified array.
   */
  public ByteArrayList(byte[] data) {
    array = new byte[(int) (data.length * 1.1) + 1];
    size = data.length;
    System.arraycopy(data, 0, array, 0, size);
  }

  // ---------------------------------------------------------------- conversion

  /**
   * Returns an array containing all of the elements in this list in the correct order.
   */
  public byte[] toArray() {
    byte[] result = new byte[size];
    System.arraycopy(array, 0, result, 0, size);
    return result;
  }

  // ---------------------------------------------------------------- methods

  /**
   * Returns the element at the specified position in this list.
   */
  public byte get(int index) {
    checkRange(index);
    return array[index];
  }

  /**
   * Returns the number of elements in this list.
   */
  public int size() {
    return size;
  }

  /**
   * Removes the element at the specified position in this list.
   * Shifts any subsequent elements to the left (subtracts
   * one from their indices).
   *
   * @param index the index of the element to remove
   * @return the value of the element that was removed
   * @throws UnsupportedOperationException when this operation is not
   *                                       supported
   * @throws IndexOutOfBoundsException   if the specified index is out of range
   */
  public byte remove(int index) {
    checkRange(index);
    byte oldval = array[index];
    int numtomove = size - index - 1;
    if (numtomove > 0) {
      System.arraycopy(array, index + 1, array, index, numtomove);
    }
    size--;
    return oldval;
  }
  /**
   * Removes from this list all of the elements whose index is between fromIndex,
   * inclusive and toIndex, exclusive. Shifts any succeeding elements to the left (reduces their index).
   */
  public void removeRange(int fromIndex, int toIndex) {
    checkRange(fromIndex);
    checkRange(toIndex);
    if (fromIndex >= toIndex) {
      return;
    }
    int numtomove = size - toIndex;
    if (numtomove > 0) {
      System.arraycopy(array, toIndex, array, fromIndex, numtomove);
    }
    size -= (toIndex - fromIndex);
  }

  /**
   * Replaces the element at the specified position in this list with the specified element.
   *
   * @param index   the index of the element to change
   * @param element the value to be stored at the specified position
   * @return the value previously stored at the specified position
   */
  public byte set(int index, byte element) {
    checkRange(index);
    byte oldval = array[index];
    array[index] = element;
    return oldval;
  }

  /**
   * Appends the specified element to the end of this list.
   */
  public void add(byte element) {
    ensureCapacity(size + 1);
    array[size++] = element;
  }

  /**
   * Inserts the specified element at the specified position in this list.
   * Shifts the element currently at that position (if any) and any subsequent
   * elements to the right (adds one to their indices).
   *
   * @param index   the index at which to insert the element
   * @param element the value to insert
   */
  public void add(int index, byte element) {
    checkRangeIncludingEndpoint(index);
    ensureCapacity(size + 1);
    int numtomove = size - index;
    System.arraycopy(array, index, array, index + 1, numtomove);
    array[index] = element;
    size++;
  }

  /**
   * Appends all of the elements in the specified array to the end of this list.
   */
  public void addAll(byte[] data) {
    int dataLen = data.length;
    if (dataLen == 0) {
      return;
    }
    int newcap = size + (int) (dataLen * 1.1) + 1;
    ensureCapacity(newcap);
    System.arraycopy(data, 0, array, size, dataLen);
    size += dataLen;
  }

  /**
   * Appends all of the elements in the specified array at the specified position in this list.
   */
  public void addAll(int index, byte[] data) {
    int dataLen = data.length;
    if (dataLen == 0) {
      return;
    }
    int newcap = size + (int) (dataLen * 1.1) + 1;
    ensureCapacity(newcap);
    System.arraycopy(array, index, array, index + dataLen, size - index);
    System.arraycopy(data, 0, array, index, dataLen);
    size += dataLen;
  }

  /**
   * Removes all of the elements from this list.
   * The list will be empty after this call returns.
   */
  public void clear() {
    size = 0;
  }

  // ---------------------------------------------------------------- search

  /**
   * Returns true if this list contains the specified element.
   */
  public boolean contains(byte data) {
    for (int i = 0; i < size; i++) {
      if (array[i] == data) {
        return true;
      }
    }
    return false;
  }


  /**
   * Searches for the first occurence of the given argument.
   */
  public int indexOf(byte data) {
    for (int i = 0; i < size; i++) {
      if (array[i] == data) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Returns the index of the last occurrence of the specified object in this list.
   */
  public int lastIndexOf(byte data) {
    for (int i = size - 1; i >= 0; i--) {
      if (array[i] == data) {
        return i;
      }
    }
    return -1;
  }

  /**
   * Tests if this list has no elements.
   */
  public boolean isEmpty() {
    return size == 0;
  }



  // ---------------------------------------------------------------- capacity

  /**
   * Increases the capacity of this ArrayList instance, if necessary,
   * to ensure that it can hold at least the number of elements specified by
   * the minimum capacity argument.
   */
  public void ensureCapacity(int mincap) {
    if (mincap > array.length) {
      int newcap = ((array.length * 3) >> 1) + 1;
      byte[] olddata = array;
      array = new byte[newcap < mincap ? mincap : newcap];
      System.arraycopy(olddata, 0, array, 0, size);
    }
  }

  /**
   * Trims the capacity of this instance to be the list's current size.
   * An application can use this operation to minimize the storage of some instance.
   */
  public void trimToSize() {
    if (size < array.length) {
      byte[] olddata = array;
      array = new byte[size];
      System.arraycopy(olddata, 0, array, 0, size);
    }
  }

  // ---------------------------------------------------------------- serializable

  private void writeObject(ObjectOutputStream out) throws IOException {
    out.defaultWriteObject();
    out.writeInt(array.length);
    for (int i = 0; i < size; i++) {
      out.writeByte(array[i]);
    }
  }

  private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
    in.defaultReadObject();
    array = new byte[in.readInt()];
    for (int i = 0; i < size; i++) {
      array[i] = in.readByte();
    }
  }

  // ---------------------------------------------------------------- privates

  private void checkRange(int index) {
    if (index < 0 || index >= size) {
      throw new IndexOutOfBoundsException("Index should be at least 0 and less than " + size + ", found " + index);
    }
  }

  private void checkRangeIncludingEndpoint(int index) {
    if (index < 0 || index > size) {
      throw new IndexOutOfBoundsException("Index should be at least 0 and at most " + size + ", found " + index);
    }
  }

}