在java中，什么时候一个对象变得无法访问？ [英] In java when does an object become unreachable?

问题描述

在java中，什么是不可达对象？什么时候该对象变得无法访问？在学习垃圾收集的时候，我无法理解这个概念。

任何人都可以用例子给出任何想法吗？

解决方案

当不再有任何引用变量引用它时，或者当它在孤岛中孤儿。

一个具有指向它的引用变量的对象，但该对象没有指向它的引用变量。

  class A {int我= 5; } 
 class B {A a = new A（）; } 
 class C {
 B b; 
 public static void main（String args []）{
 C c = new C（）; 
 c.b = new B（）; 
 // A，B和C的实例创建
 c.b = null; 
 // B和A的实例可以被垃圾收集。 
 
 
 
 $ b编辑：只想指出，现在它在一个岛上，因为B的实例没有提及它。 A实例有资格进行垃圾回收。
 
In java, what is an unreachable object? When does the object become unreachable? While studying garbage collection i was not able to understand this concept.

Can anyone give any ideas with examples?
解决方案
When there are no longer any reference variables referring to it, OR when it is orphaned in an island.

An island being an object that has a reference variable pointing to it, however that object has no reference variables pointing to it.
class A { int i = 5; }
class B { A a = new A(); }
class C {
   B b;
   public static void main(String args[]) {
      C c = new C();
      c.b = new B();
      // instance of A, B, and C created
      c.b = null;
      // instance of B and A eligible to be garbage collected.
   }
EDIT: Just want to point out that even though the instance of A has a reference, it is on an island now because the instance of B does not have a reference to it.  The A instance is eligible for garbage collection.

                        
这篇关于在java中，什么时候一个对象变得无法访问？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！