Remove key when the HashMap still is used

Question

I try to remove some value when the HashMap still is use, but I get compile error:
java.util.ConcurrentModificationException
     at java.util.HashMap$HashIterator.next(HashMap.java:749)
     at PoliceDatabase.listUnlawfulDrivers(PoliceDatabase.java:228)
part of code as follow:
do {
while (de.hasNext()) {
p=(Driver)de.next();
maxt=((ArrayList)tempInfractions.get(p)).size();
if (maxt==0) {tempInfractions.remove(p);}
else if (maxt>max) {
max=maxt;p1=p;
atemp1.addAll((ArrayList)tempInfractions.get(p));}
newInfractions.put(p1,atemp1);
atemp1.clear();
tempInfractions.remove(p1);     } while (tempInfractions.isEmpty());
what should I do?
Thank you first!!

Answer 1

I try to remove some value when the HashMap still is
use, but I get compile error:That's a run time error, not a compiler error.
>
java.util.ConcurrentModificationException
at
java.util.HashMap$HashIterator.next(HashMap.java:749)
at
PoliceDatabase.listUnlawfulDrivers(PoliceDatabase.java:
28)
part of code as follow:
do {
while (de.hasNext()) {
p=(Driver)de.next();
maxt=((ArrayList)tempInfractions.get(p)).size();
if (maxt==0) {tempInfractions.remove(p);}I assume "de" is some kind of iterator. You'll have to remove "p" via the iterator so it will know that element is gone. Look in the API docs for whichever iterator you're using for a remove() method.