import java.util.Random;
public class Test
{
public static void main( String[] args )
{
Random random = new Random();
int[] array = new int[5000000];
for( int i = 0 ; i < array.length ; i ++ )
array[i] = random.nextInt();

int loop = 10;
int[] buf = new int[ array.length ];
System.out.println("array copy");
long start;
for( int i = 0 ; i < loop ; i ++ )
{
start = System.currentTimeMillis();
System.arraycopy( array , 0 , buf , 0 , array.length );
System.out.println( System.currentTimeMillis() - start );
}

System.out.println( "assignment copy" );

for( int i = 0 ; i < loop ; i ++ )
{
start = System.currentTimeMillis();
for( int j = 0 ; j < array.length ; j ++ )
buf[j] = array[j];
System.out.println( System.currentTimeMillis() - start );
}
}
}