Synchronized block in java

Question

I came across the code:

synchronized(Account.this)   
{}

where Account is a class.
Does Account.this mean any current instance of class Account?

Are you sure "Account" is a class and not a poorly named variable? — Jeanne Boyarsky, Oct 30 '13 at 00:33
`Account.this` is referring to an instance of `Account`, in particular, "this" instance of the `Account`. It may be that the reference is being made from within in an inner class where it's not possible to use `this` directly... — MadProgrammer, Oct 30 '13 at 00:35
I imagine the code is in an anonymous or otherwise inner class and this the lock is on the outer class. — Boris the Spider, Oct 30 '13 at 00:35
This explanation of the `Class.this` syntax might be relevant: http://stackoverflow.com/a/5530293/2288659 — Silvio Mayolo, Oct 30 '13 at 00:36
This is a question not about multithreading but rather about Java syntax. I don't think the latter two tags are appropriate. — arshajii, Oct 30 '13 at 00:36

OldCurmudgeon · Answer 1 · 2013-10-30T08:51:18.737

4

This would probably be from an inner class of Account.

class Account {
  class InnerAccount {
    ...
    synchronized(Account.this) {
    }
  }
}

edited Oct 30 '13 at 08:51

answered Oct 30 '13 at 00:36

OldCurmudgeon

score 1 · Accepted Answer · answered Oct 30 '13 at 00:36

1

Normally it is used inside of an inner class: It means the this instance of the outer Account class.

Writing this by itself will return the instance of the inner class, not the outer class.

answered Oct 30 '13 at 00:36

Samuel O'Malley

2 Answers2