Iterator on JsonArray issue

[Scott Brown]

Good afternoon,

I got around this by using a for loop, but I'm confused as how the iterator is supposed to function?


This code with a JsonArray containing one JsonObject results in an infinite loop:

while(jsonArray.iterator().hasNext()) {
   JsonObject myObject = jsonArray.iterator().next();
}

This code with a JsonArray containing one JsonObject results in an exception on the call to remove:

while(jsonArray.iterator().hasNext()) {
   JsonObject myObject = jsonArray.iterator().next();
   jsonArray.iterator().remove();
}

Was I doing it wrong?

[Tim Yates]

Not sure why you are creating a new iterator every time you try to access it...

Have you tried:

Iterator i = jsonArray.iterator() ;

while( i.hasNext() ) {

    Object myObject = i.next() ;

}

Tim

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[Tim Fox]

On 11/06/13 20:15, Tim Yates wrote:
> Not sure why you are creating a new iterator every time you try to access
> it...
>
> Have you tried:
>
> Iterator i = jsonArray.iterator() ;
> while( i.hasNext() ) {
> Object myObject = i.next() ;
> }

+1

or even better

for (Object myObject: jsonArray) {

[Mariam Hakobyan]

Hi Tim,

I have exactly the same problem, and I am not sure iterator() method works correctly.

I am using JsonArray wich was constructed like this:

JsonArray array = new JsonArray(new String[] {"text1", "text2", "text3"});

and when I try to iterate through it:

Iterator iterator = array.iterator();

if(iterator.hasNext()) {

     nextAddress = (String)iterator.next();

     iterator.remove();

}

I get a java.lang.UnsupportedOperationException exception on remove() method. Am I doing anything wrong here? Is this supposed to work?

Thanks in advance,

Mariam

[Stream Liu]

Well, you create JsonArray with an Array which make list in
JsonArray as a fixed-size list, so iterator remove dosen't support this
operation.

You could create JsonArray with List<String> which would be work as you
wanna.

but i think this would be a little fault of vert.x

>> > On 11 June 2013 18:30, Scott Brown <scott...@gmail.com <javascript:>>

>> wrote:
>> >
>> >> Good afternoon,
>> >>
>> >> I got around this by using a for loop, but I'm confused as how the
>> >> iterator is supposed to function?
>> >>
>> >>
>> >> This code with a JsonArray containing one JsonObject results in an
>> >> infinite loop:
>> >>
>> >> while(jsonArray.iterator().hasNext()) {
>> >> JsonObject myObject = jsonArray.iterator().next();
>> >> }
>> >>
>> >>
>> >> This code with a JsonArray containing one JsonObject results in an
>> >> exception on the call to remove:
>> >>
>> >> while(jsonArray.iterator().hasNext()) {
>> >> JsonObject myObject = jsonArray.iterator().next();
>> >> jsonArray.iterator().remove();
>> >> }
>> >>
>> >> Was I doing it wrong?
>> >>
>> >> --
>> >> You received this message because you are subscribed to the Google
>> Groups
>> >> "vert.x" group.
>> >> To unsubscribe from this group and stop receiving emails from it, send
>> an

>> >> email to vertx+un...@googlegroups.com <javascript:>.

[Mariam Hakobyan]

Hi Stream.liu,

Thanks for the answer, that was the cause of the exception. When I use List<Object> (List<String> as an argument of JsonArray is not supported by vertx), it works fine.

Mariam