How to replace text(tag) with HTML in docx using Apache POI?

1
votes

We are going to have some template docx file, where will be some tags like ${content}. I need to replace this tags with HTML.

For this purpose I want to use altChunk element in XWPFDocument. Following answer in How to add an altChunk element to a XWPFDocument using Apache POI, I could place altChunk in the end of docx.

How can I replace my tag with it? Or could I use any other libraries, may be docx4j?

UPD: Template docx files with tags are created by end users with MS Word and looks like: Sample docx template

1
javahtmlapache-poidocx
"How can I replace my tag with it?" Depends on where the tag is. According to Office Open XML specification, altChunk can only occur in IBody elements. So if your ${content} is in a text run, then this cannot be replaced with altChunk. Only if ${content} is a IBodyElement of it's own, then finding that IBodyElement, creating a XMLCursor, inserting the altChunk, then removing the IBodyElement would be possible. – Axel Richter
@AxelRichter, if this tag is written in MS Word, is it considered to be as IBodyElement? If not, do you know how to make it IBodyElement using MS Word? See my update, pls. May be I should not replace, may be I could place it just after tag, and then remove text with tag. Any ideas? – Max
Looks as if it is it's own paragraph, so it is a IBodyElement. Will try providing a solution this evening (Germany). – Axel Richter

1 Answers

5
votes

If "${content}" is in a IBodyElement of it's own, then solving that requirement by finding that IBodyElement, creating a XmlCursor, inserting the altChunk, then removing the IBodyElement would be possible.

The following code demonstrates this by extending the example in How to add an altChunk element to a XWPFDocument using Apache POI. It provides a method for replacing a found IBodyElement, which contains a special text, with a altChunk which references a MyXWPFHtmlDocument. It uses XmlCursor to get the needed position in the text body. The usage of XmlCursor is commented in the code.

template.docx:

enter image description here

Code:

import java.io.*;

import org.apache.poi.*;
import org.apache.poi.ooxml.*;
import org.apache.poi.openxml4j.opc.*;

import org.apache.poi.xwpf.usermodel.*;

import org.apache.xmlbeans.XmlCursor;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTAltChunk;

public class WordInsertHTMLaltChunkInDocument {

 //a method for creating the htmlDoc /word/htmlDoc#.html in the *.docx ZIP archive  
 //String id will be htmlDoc#.
 private static MyXWPFHtmlDocument createHtmlDoc(XWPFDocument document, String id) throws Exception {
  OPCPackage oPCPackage = document.getPackage();
  PackagePartName partName = PackagingURIHelper.createPartName("/word/" + id + ".html");
  PackagePart part = oPCPackage.createPart(partName, "text/html");
  MyXWPFHtmlDocument myXWPFHtmlDocument = new MyXWPFHtmlDocument(part, id);
  document.addRelation(myXWPFHtmlDocument.getId(), new XWPFHtmlRelation(), myXWPFHtmlDocument);
  return myXWPFHtmlDocument;
 }

 //a method for replacing a IBodyElement containing a special text with CTAltChunk which
 //references MyXWPFHtmlDocument
 private static void replaceIBodyElementWithAltChunk(XWPFDocument document, String textToFind, 
                                                     MyXWPFHtmlDocument myXWPFHtmlDocument) throws Exception {
  int pos = 0;
  for (IBodyElement bodyElement : document.getBodyElements()) {
   if (bodyElement instanceof XWPFParagraph) {
    XWPFParagraph paragraph = (XWPFParagraph)bodyElement;
    String text = paragraph.getText();
    if (text != null && text.contains(textToFind)) {
     //create XmlCursor at this paragraph
     XmlCursor cursor = paragraph.getCTP().newCursor();
     cursor.toEndToken(); //now we are at end of the paragraph
     //there always must be a next start token. Either a p or at least sectPr.
     while(cursor.toNextToken() != org.apache.xmlbeans.XmlCursor.TokenType.START);
     //now we can insert the CTAltChunk here
     String uri = CTAltChunk.type.getName().getNamespaceURI();
     cursor.beginElement("altChunk", uri);
     cursor.toParent();
     CTAltChunk cTAltChunk = (CTAltChunk)cursor.getObject();
     //set the altChunk's Id to reference the given MyXWPFHtmlDocument
     cTAltChunk.setId(myXWPFHtmlDocument.getId());

     //now remove the found IBodyElement
     document.removeBodyElement(pos);

     break; //break for each loop
    }
   }
   pos++;
  }
 }

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

  XWPFDocument document = new XWPFDocument(new FileInputStream("template.docx"));

  MyXWPFHtmlDocument myXWPFHtmlDocument = createHtmlDoc(document, "htmlDoc1");
  myXWPFHtmlDocument.setHtml(myXWPFHtmlDocument.getHtml().replace("<body></body>",
   "<body><p>Simple <b>HTML</b> <i>formatted</i> <u>text</u></p></body>"));

  replaceIBodyElementWithAltChunk(document, "${content}", myXWPFHtmlDocument);

  FileOutputStream out = new FileOutputStream("result.docx");
  document.write(out);
  out.close();
  document.close();

 }

 //a wrapper class for the  htmlDoc /word/htmlDoc#.html in the *.docx ZIP archive
 //provides methods for manipulating the HTML
 //TODO: We should *not* using String methods for manipulating HTML!
 private static class MyXWPFHtmlDocument extends POIXMLDocumentPart {

  private String html;
  private String id;

  private MyXWPFHtmlDocument(PackagePart part, String id) throws Exception {
   super(part);
   this.html = "<!DOCTYPE html><html><head><style></style><title>HTML import</title></head><body></body>";
   this.id = id;
  }

  private String getId() {
   return id;
  }

  private String getHtml() {
   return html;
  }

  private void setHtml(String html) {
   this.html = html;
  }

  @Override
  protected void commit() throws IOException {
   PackagePart part = getPackagePart();
   OutputStream out = part.getOutputStream();
   Writer writer = new OutputStreamWriter(out, "UTF-8");
   writer.write(html);
   writer.close();
   out.close();
  }

 }

 //the XWPFRelation for /word/htmlDoc#.html
 private final static class XWPFHtmlRelation extends POIXMLRelation {
  private XWPFHtmlRelation() {
   super(
    "text/html", 
    "http://schemas.openxmlformats.org/officeDocument/2006/relationships/aFChunk", 
    "/word/htmlDoc#.html");
  }
 }
}

result.docx:

enter image description here