What is escaping reference?

What is escaping reference?

If the reference escapes, something can use the object before its constructor has completed the initialization and see it in an inconsistent (partly initialized) state. Even if the object escapes after initialization has completed, declaring a subclass can cause this to be violated.

What is leaking in a constructor?

Leaking this from the constructor thus means that the external world gets access to an object which is not yet fully constructed. This may not necessarily lead to problems in a a single-threaded program (although it is possible, but the problem is much more obvious in this case).

Can a reference escape during object construction?

Consequently, programs must not allow the this reference to escape during object construction. In general, it is important to detect cases in which the this reference can leak out beyond the scope of the current context. In particular, public variables and methods should be carefully scrutinized.

When is a reference said to have escaped?

The this reference is said to have escaped when it is made available beyond its current scope. Following are common ways by which the this reference can escape: constructed. (For more information, see rule MET05-J. Ensure that constructors do not call overridable methods.)

How can this reference escape from a class?

Following are common ways by which the this reference can escape: constructed. (For more information, see rule MET05-J. Ensure that constructors do not call overridable methods.) Returning this from a nonprivate method of a mutable class, which allows the caller to manipulate the object’s state indirectly.

What does escape mean when building an object?

“Escape” means that a reference to the partially-constructed this object might be passed to some other object in the system. Consider this scenario: The problem is that the new Bar object is being registered with otherObject before its construction is completed.