2 small examples of [Java] memory leaks __java

Public Object pop () { 
if (size==0) throw new Emptystackexception (); 
return element[--size]; Transient memory leak 
} 

Each time the above code pops (), stack pops up an element, and there is actually a reference element[x to the object that has popped up before the new element is added, so the GC is not garbage collected. Only the push () of the new element makes the Element[x]=newobject, which makes the previously created object likely to be reclaimed. It is much safer to change the above pop () method to the following code:

Public Object pop () {  
       if (element.length==size) throws Emptystackexception ();  
       Object O=element[--size];  
       Elements[size]=null;  Gives GC a chance to recycle this object return   
       o;  
}  

B.getinstance (). SetA (this);

private static B Instance=new B (); 

public static B getinstance () { 

Obviously B uses singleton mode, he holds a reference to a object, and the object of Class A cannot be reclaimed. Imagine what happens if a is a larger object or a collection type.

Vector v = new vector (a);
for (int i = 1; i<100; i++)
{object o = new Object ();
V.add (o);
o = null;
}