How to remove elements from a queue in Java with a loop -

How to remove elements from a queue in Java with a loop -

i have info construction this:

blockingqueue mailbox = new linkedblockingqueue();

i'm trying this:

for(mail mail: mailbox) { if(badnews(mail)) { mailbox.remove(mail); } }

obviously contents of loop interfere bounds , error triggered, this:

for(int = 0; < mailbox.size(); i++) { if(badnews(mailbox.get(i))) { mailbox.remove(i); i--; } }

but sadly blockingqueue's don't have function or remove element index, i'm stuck. ideas?

edit - few clarifications: 1 of goals maintain same ordering popping head , putting tail no good. also, although no other threads remove mail service mailbox, add together it, don't want in middle of removal algorithm, have send me mail, , have exception occur.

thanks in advance!

you may p̶o̶p̶ poll , p̶u̶s̶h̶ offer elements in queue until create finish loop on queue. here's example:

mail firstmail = mailbox.peek(); mail service currentmail = mailbox.pop(); while (true) { //a base of operations status stop loop mail service tempmail = mailbox.peek(); if (tempmail == null || tempmail.equals(firstmail)) { mailbox.offer(currentmail); break; } //if there's nil wrong current mail, re add together mailbox if (!badnews(currentmail)) { mailbox.offer(currentmail); } currentmail = mailbox.poll(); }

note approach work if code executed in single thread , there's no other thread removes items queue.

maybe need check if want poll or take elements blockingqueue. similar offer , put.

more info:

java blockingqueue take() vs poll() linkedblockingqueue set vs offer

another less buggy approach using temporary collection, not concurrent, , store elements still need in queue. here's kickoff example:

list<mail> maillisttemp = new arraylist<>(); while (mailbox.peek() != null) { mail service mail = mailbox.take(); if (!badnews(mail)) { maillisttemp.add(mail); } } (mail mail service : maillisttemp) { mailbox.offer(mail); }

java loops blockingqueue