Apache POI XWPF does not replace but concatenates

Question

I'm new with Apache POI and I'm having trouble replacing text.

I copied my code here Replacing a text in Apache POI XWPF not working

It works but it does not replace the text but concatenates it. So if I have "Quick brown fox jumps over" and replace "over" with "under". I get "Quick brown fox jumps overQuick brown fox jumps under".

What is wrong?

So here's the code:

public class testPOI {

    public static void main(String[] args) throws Exception{

        String filepath = "F:\\MASTER_DOC.docx";
        String outpath = "F:\\Test.docx";

        XWPFDocument doc = new XWPFDocument(new FileInputStream(filepath));
        for (XWPFParagraph p : doc.getParagraphs()){

            int numberOfRuns = p.getRuns().size();

            // Collate text of all runs
            StringBuilder sb = new StringBuilder();
            for (XWPFRun r : p.getRuns()){
                int pos = r.getTextPosition();
                if(r.getText(pos) != null) {
                    sb.append(r.getText(pos));
                }
            }

            // Continue if there is text and contains "test"
            if(sb.length() > 0 && sb.toString().contains("test")) {
                // Remove all existing runs
                for(int i = 0; i < numberOfRuns; i++) {
                    p.removeRun(i);
                }
                String text = sb.toString().replace("test", "DOG");
                // Add new run with updated text
                XWPFRun run = p.createRun();
                run.setText(text);
                p.addRun(run);
            }
        }
       doc.write(new FileOutputStream(outpath));
    }
}

EDIT 1: THIS IS WEIRD! I tried replacing on 2nd run works fine. Something is wrong with 1st run. Can anyone point it out?

What happens if you try to remove the runs from end to beginning for(int i = numberOfRuns-1; i >=0; i--) { p.removeRun(i); } — Clemens Klein-Robbenhaar
@ClemensKlein-Robbenhaar It worked! Is there an explanation on why? — Audix
You modify (shorten) a list while iterating over it. Iterating in "forward"-direction causes you to hop over every second item in the list. (If wanted I can provide a separate answer for details.) It seems that p.removeRun(i); does not throw IndexOutOfBoundsException if i is larger then the size of the list or the problem would have been obvious. — Clemens Klein-Robbenhaar

Audix Audix · Accepted Answer · 2015-03-09T02:16:06

I tried this. It works.

    public class testPOI {

public static void main(String[] args) throws Exception{

    String filepath = "F:\\MASTER_DOC.docx";
    String outpath = "F:\\Test.docx";

    XWPFDocument doc = new XWPFDocument(new FileInputStream(filepath));
    for (XWPFParagraph p : doc.getParagraphs()){

        int numberOfRuns = p.getRuns().size();

        // Collate text of all runs
        StringBuilder sb = new StringBuilder();
        for (XWPFRun r : p.getRuns()){
            int pos = r.getTextPosition();
            if(r.getText(pos) != null) {
                sb.append(r.getText(pos));
            }
        }

        // Continue if there is text and contains "test"
        if(sb.length() > 0 && sb.toString().contains("test")) {
            // Remove all existing runs
            for(int i = numberOfRuns; i >=0 ; i--) {
                p.removeRun(i);
            }
            String text = sb.toString().replace("test", "DOG");
            // Add new run with updated text
            XWPFRun run = p.createRun();
            run.setText(text);
            p.addRun(run);
        }
    }
   doc.write(new FileOutputStream(outpath));
}
}

Apache POI XWPF does not replace but concatenates

1 Answers