Java匿名对象和垃圾收集第-1部分

Question

public void function(){
   new Student().setName("john");
}

public void function(){
   Student student = new Student();
   student.setName("john");
}

Does GC behave differently for both of the snip?

I mean which case (CASE-1/CASE-2) is more GC efficient in terms of Time?

Answer 1

Does GC behave differently for both of the snip?

没有。调用 setName 方法后，使用 new Student 创建的 Student 对象将不再可访问，并且可以被垃圾回收。

I mean which case (CASE-1/CASE-2) is more GC efficient in terms of Time?

两者都没有更高效。第一种情况在字节码中会少一个赋值。这不会影响 GC。

来自JLS

A reachable object is any object that can be accessed in any potential continuing computation from any live thread.

在这两个片段中，调用 setName 后，Student 对象不再可访问(假设构造函数和 setName 方法不可用)不会泄漏对该对象的引用 - 但即使在这种情况下，两个片段的行为也是相同的)。