Java Singleton模式 [英] Java Singleton Pattern

问题描述

编辑：已回答 - 错误是方法不是静态

我使用了 Singleton Design Pattern

  public class Singleton {
 private static Singleton INSTANCE = new Singleton（）; 
 
 //私有构造函数阻止从其他类实例化
 private Singleton（）{} 
 
 public static Singleton getInstance（）{
 return INSTANCE; 
} 
} 
  

我的问题是如何创建类的对象单击另一个类？

我尝试过：

  Singleton singleton = new Singleton（）; 
 // error  -  constructor is private 
 Singleton singleton = Singleton.getInstance（）; 
 //错误 - 非静态方法无法从静态上下文中引用
  

什么是正确的代码？

谢谢，
Spencer

解决方案

<$ Singleton singleton = Singleton.getInstance（）; p $ p>


是正确的方法。确保您的 getInstance（）方法确实是 static 。

由于您的 Singleton 实现远未安全 - 您的对象可以通过反射进行实例化，您可能需要基于 枚举

Edit: Answered - error was method wasn't static

I'm used the Singleton Design Pattern

 public class Singleton {
   private static final Singleton INSTANCE = new Singleton();

   // Private constructor prevents instantiation from other classes
   private Singleton() {}

   public static Singleton getInstance() {
      return INSTANCE;
   }
 }

My question is how do I create an object of class Singleton in another class?

I've tried:

Singleton singleton = new Singleton(); 
// error - constructor is private
Singleton singleton = Singleton.getInstance();
// error - non-static method cannot be referenced from a static context

What is the correct code?

Thanks, Spencer

解决方案

Singleton singleton = Singleton.getInstance();

is the correct way. Make sure your getInstance() method is indeed static.

Since your Singleton implementation is far from being safe - your object can be instantiated via reflection, you may want to create a singleton based on enum

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