jsoup在element.remove（）上抛出IndexOutOfBoundsException

Question

I am writing a script that cleans up web pages. This includes iterating through all the tags (elements) and checking against certain rules:

    for (Element element :  document.select("*") ) {
        if (element == null) { 
            continue;
        }


        if ( RULE1) ) {
            element.remove();
        }


        else if( RULE2){
            element.remove();
        }


        else if ( RULE3 ) {
            element.remove();
        }

        else if (  RULE4 ) {
            element.remove();
        }

    }   

I have tested this on tens of pages without a problem. Today I just hit a web page throws java.lang.IndexOutOfBoundsException :

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 3, Size: 1
    at java.util.ArrayList.rangeCheck(ArrayList.java:653)
    at java.util.ArrayList.remove(ArrayList.java:492)
    at org.jsoup.nodes.Node.removeChild(Node.java:423)
    at org.jsoup.nodes.Node.remove(Node.java:266)

My guess is that at some point the code tries to remove an element that's already removed. But can't tell how/why this should happen.

Any idea?

Thanks.

Edit 1: Rule causing break

I found out the rule that's causing the code to fail. One of the rules actually doesn't remove the element but resets its text:

        else if ( matches junk text ) {
            String match = getMatchingJunk ( element.ownText() );
            if ( match.length()  < JUNK_TEXT_ELEMENT_REMOVAL_THRESH ) {
                element.text( removeSmallest(element.ownText(), match) ); // <= causing error
                continue;
            }

            element.remove();

        }

If I remove the line element.text( removeSmallest(element.ownText(), match) ) the error disappears.

Answer 1

The code seems to work if I purge junk text in 2 phases. The code looks a bit repetitive and hackish. Probably there's a better way to do it:

1st Phase: Collect all junks

        Map <String, Element> junks = new HashMap <String, Element>();
        for (Element element :  document.select("*") ) {
            ...

            if () {
                ...
            }

            else if ( matches junk text ) {
                String match = getMatchingJunk ( element.ownText() );
                if ( match.length()  < JUNK_TEXT_ELEMENT_REMOVAL_THRESH ) {
                    //element.text( removeSmallest(element.ownText(), match) ); // <= causing error
                    junks.put(elOwnText,element);
                    continue;
                }

                element.remove();

            }
        }

2nd phase: Purge junk

    if ( size(junks) > 0 ) {
        for(Map.Entry<String,Element> ent : junks.entrySet()){

            String match = getMatchingJunk (ent.getKey()); // this looks repetitive. probably there's a better way to do it
            if ( match.length()  < JUNK_TEXT_ELEMENT_REMOVAL_THRESH ) {
                ent.getValue().text( removeSmallest(ent.getKey(), match) ); // purge junk

            }
        } // end for
    } // end if