使用静态变量来计算实例

public class CountTestApp

{/** from nowjava.com - 时代Java**/

    public static void main(String[] args)

    {

    printCount();

    for (int i = 0; i < 10; i++)

    {

      CountTest c1 = new CountTest();

      printCount();

    }


    }
//来 自 nowjava.com

    private static void printCount()

    {

    System.out.println("There are now "

        + CountTest.getInstanceCount()

        + " instances of the CountTest class.");

  }

}


class CountTest

{

    private static int instanceCount = 0;


    public CountTest()

    {

        instanceCount++;

    }