Pfthb

I am trying to replace a string pattern for another one with hyperlink, but I am getting java.util.ConcurrentModificationException. The lines of code which the error is pointing don't make sense, so I wasn't able to find out what happened.

 // Replace occurrences in all paragraphs
 for (XWPFParagraph p : doc_buffer.getParagraphs()) 
 List<XWPFRun> p_runs = p.getRuns();
 if (p_runs != null) 
 for (XWPFRun r : p_runs) 
 String text = r.getText(0);
 if ((text != null) && (text.contains(pattern))) 
 if (pattern.equals("LINK_TO_DOCS")) 
 //TODO
 String h_url = "http://example.com/linktodocs/";
 String h_text = replacement;

 // Creates the link as an external relationship
 XWPFParagraph temp_p = doc_buffer.createParagraph();
 String id = temp_p.getDocument().getPackagePart().addExternalRelationship(h_url, XWPFRelation.HYPERLINK.getRelation()).getId();

 // Binds the link to the relationship
 CTHyperlink link = temp_p.getCTP().addNewHyperlink();
 link.setId(id);

 // Creates the linked text
 CTText linked_text = CTText.Factory.newInstance();
 linked_text.setStringValue(h_text);

 // Creates a wordprocessing Run wrapper
 CTR ctr = CTR.Factory.newInstance();
 ctr.setTArray(new CTText linked_text);
 link.setRArray(new CTR ctr);

 r = new XWPFHyperlinkRun(link, r.getCTR(), r.getParent());
 
 else 
 text = text.replaceAll(pattern, replacement);
 r.setText(text, 0);
 

 
 
 
 

Console error:

Exception in thread "main" java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
at java.util.ArrayList$Itr.next(ArrayList.java:859)
at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1042)
at releasenotes.ReleaseNotesUpdater.replaceAllOccurrences(ReleaseNotesUpdater.java:263)
at releasenotes.ReleaseNotesUpdater.main(ReleaseNotesUpdater.java:85)

Also, besides this error, I also would like some advice about how can I replace a string pattern for another one with hyperlink. I have searched but I am a bit confused about how it works.

Edit.:
at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1042)

 public Iterator<E> iterator() 
 return new Iterator<E>() 
 private final Iterator<? extends E> i = c.iterator();

 public boolean hasNext() return i.hasNext();
 public E next() return i.next();
 public void remove() 
 throw new UnsupportedOperationException();
 
 @Override
 public void forEachRemaining(Consumer<? super E> action) 
 // Use backing collection version
 i.forEachRemaining(action);
 
 ;
 

at java.util.ArrayList$Itr.next(ArrayList.java:859)

 @SuppressWarnings("unchecked")
 public E next() 
 checkForComodification();
 int i = cursor;
 if (i >= size)
 throw new NoSuchElementException();
 Object elementData = ArrayList.this.elementData;
 if (i >= elementData.length)
 throw new ConcurrentModificationException();
 cursor = i + 1;
 return (E) elementData[lastRet = i];
 

at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)

 final void checkForComodification() 
 if (modCount != expectedModCount)
 throw new ConcurrentModificationException();
 

I have found the solution so I am sharing if anyone has the same trouble.

To replace a common run with a Hyperlink run, simply do the following:

 String h_url = "http://example.com/index.html";
 String h_text = replacement;

 // Creates the link as an external relationship
 String id = r.getDocument().getPackagePart()
 .addExternalRelationship(h_url, XWPFRelation.HYPERLINK.getRelation()).getId();

 // Binds the link to the relationship
 CTHyperlink link = r.getParagraph().getCTP().addNewHyperlink();
 link.setId(id);

 // Creates the linked text
 CTText linked_text = CTText.Factory.newInstance();
 linked_text.setStringValue(h_text);

 // Creates a XML wordprocessing wrapper for Run
 // The magic is here
 CTR ctr = r.getCTR();
 ctr.setTArray(new CTText linked_text );

 // Stylizing
 CTRPr rpr_c = ctr.addNewRPr();
 CTColor color = CTColor.Factory.newInstance();
 color.setVal("0000FF");
 rpr_c.setColor(color);

 CTRPr rpr_u = ctr.addNewRPr();
 rpr_u.addNewU().setVal(STUnderline.SINGLE);

The code above is inside a loop which is iterating over all runs in a paragraph (r is the current run). So you just have to call r.getCTR() to be able to edit the run.

The reason why the exception was happening, was because I was trying to modify the document structure while going through it in this line:

 XWPFParagraph temp_p = doc_buffer.createParagraph();

If anyone has questions, feel free to ask in the comments.