Java单例模式

单例模式：一个类只会生成唯一的一个对象

• 代码一 ：

public class SingpatternTest
{
  public static void main(String[] args)
  {
      Singpattern singpattern1 = singpattern.getInstance();
      Singpattern singpattern2 = singpattern.getInstance();
      system.out.println(singpattern1  == singpattern2);
  }

}

class Singpattern
{

  private  static Singpattern singpattern = new Singpattern();

  private Singpattern()
  {

  }

  public  static Singpattern getInstance()
  {
    return new Singleton();
  }

}

• 代码二 ：

public class SingpatternTest
{
  public static void main(String[] args)
  {
      Singpattern singpattern1 = singpattern.getInstance();
      Singpattern singpattern2 = singpattern.getInstance();
      system.out.println(singpattern1  == singpattern2);
  }

}
class Singpattern
{
  private  static Singpattern singpattern;

  private Singpattern()
  {

  }

  public  static Singpattern getInstance()
  {
    if(singpattern = null)
    {
       singpattern = new Singpattern();
     }

    return new Singleton();
  }

}