However, when you're dealing with old code and you're using synchronized blocks, you should call wait() on the object that's being synchronized on. Since you should never synchronize on this, but instead on a private field, your question becomes moot.
The "this" is implied in that case, just as it is when you call any other instance method without an explicit reference. That means that wait() is called on the current object.
raja singh kumar wrote: If you don't see an instance in the code, then it is likely in an instance method, and hence, the instance is referred to by the this reference.
No there is no "this" keyword used. It is just called as wait() in the try block