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Garbage Collection

 
Greenhorn
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37. Which of the following statements about Java's garbage collection are true?
a) The garbage collector can be invoked explicitly using a Runtime object.
b) The finalize method is always called before an object is garbage collected.
c) Any class that includes a finalize method should invoke its superclass' finalize method.
d) Garbage collection behavior is very predictable.
Which statement is true:
my anwser is a.), b.) (incorrect)
 
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The correct answers are a, b, c.
The subclass finalize() method should invoke the superclass finalize() method to ensure that all parts of an object are finalized properly.
 
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I don't understand how a can be correct. It is my understanding that we can request garbage collection but we can't explicitly force it to happen.
 
Author and all-around good cowpoke
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Interpreting a is perhaps a little tricky.

a) The garbage collector can be invoked explicitly using a Runtime object.


You can certainly execute the Runtime gc() method but that "suggests that the Java Virutal Machine expend effort"... etc. If that counts as invoking than a is true.
Bill
 
meng zhou
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Yes, anwser a,b,c are proven correct. Thanks.
 
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It's possible that finalize won't be called before an object is GCed.
If an object is about to get GCed, the finalize method is called. If finalize "saves" the object (say by giving out a reference to it), the object's death has been postponed. If later on that same object is eligible for GC, finalize WON'T be called again!
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