Creates a new subarray from a larger array. : Array Insert Remove « Collections Data Structure « Java

1. Java
2. Collections Data Structure
3. Array Insert Remove

Creates a new subarray from a larger array.

     

import java.lang.reflect.Array;
import java.util.Enumeration;
import java.util.Hashtable;


     /*********************************************************************
     * Array manipulation for Java 1.1+.
     *
     * <p>
     * Java 1.1 compatible.
     * </p>
     *
     * @see
     *   ArrayLib2
     *
     * @version
     *   2003-04-07
     * @since
     *   2001-04-06
     * @author
     *   <a href="http://croftsoft.com/">David Wallace Croft</a>*/
public class Util{


    /*********************************************************************
    * Creates a new subarray from a larger array.
    *
    * <p>
    * To avoid unnecessary object creation, this method returns the
    * original array argument if the requested subarray length is the same
    * and the startIndex is 0.  That is to say, if the method arguments
    * are such that the algorithm would have created a shallow clone, the
    * original array is returned instead.
    * </p>
    *
    * @throws NullArgumentException
    *
    *   If objectArray is null.
    *
    * @throws ArrayIndexOutOfBoundsException
    *
    *   If startIndex, length, or startIndex + length are out of range.
    *
    * @return
    *
    *   Returns an array with the same component type as the old array.
    *********************************************************************/
    public static Object [ ]  subArray (
      Object [ ]  objectArray,
      int         startIndex,
      int         length )
    //////////////////////////////////////////////////////////////////////
    {

      if ( ( startIndex == 0 )
        && ( length == objectArray.length ) )
      {
        return objectArray;
      }

      Object [ ]  newArray = ( Object [ ] ) Array.newInstance (
        objectArray.getClass ( ).getComponentType ( ), length );

      System.arraycopy ( objectArray, startIndex, newArray, 0, length );

      return newArray;
    }

}

   
    
    
    
    
  

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