The Problem (Q-score 5, ranked #5th of 32 in the Word VBA archive)
The scenario as originally posted in 2012
I need to open a .doc/.dot/.docx/.dotx (I’m not picky, I just want it to work) document,
parse it for placeholders (or something similar),
put my own data,
and then return generated .doc/.docx/.pdf document.
And on top of all that, I need the tools to accomplish that to be free.
I’ve searched around for something that would soot my needs, but I can’t find anything.
Tools like Docmosis, Javadocx, Aspose etc. are commercial.
From what I’ve read Apache POI is nowhere near successfully implementing this (they currently don’t have any official developer working on Word part of framework).
The only thing that looks that could do the trick is OpenOffice UNO API.
But that is a pretty big byte for someone that has never used this API (like me).
So if I am going to jump into this, I need to make sure that I am on the right path.
Can someone give me some advice on this?
Why community consensus is tight on this one
Across 32 Word VBA entries in the archive, the accepted answer here holds elite answer (top 10 %%) status — meaning voters are unusually aligned on the right fix.
The Verified Solution — elite answer (top 10 %%) (+18)
316-line Word VBA pattern (copy-ready)
I know it’s been a long time since I’ve posted this question, and I said that I would post my solution when I’m finished.
So here it is.
I hope that it will help someone someday.
This is a full working class, and all you have to do is put it in your application, and place TEMPLATE_DIRECTORY_ROOT directory with .docx templates in your root directory.
Usage is very simple.
You put placeholders (key) in your .docx file, and then pass file name and Map containing corresponding key-value pairs for that file.
Enjoy!
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.URI;
import java.util.Deque;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.UUID;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpServletResponse;
public class DocxManipulator {
private static final String MAIN_DOCUMENT_PATH = "word/document.xml";
private static final String TEMPLATE_DIRECTORY_ROOT = "TEMPLATES_DIRECTORY/";
/* PUBLIC METHODS */
/**
* Generates .docx document from given template and the substitution data
*
* @param templateName
* Template data
* @param substitutionData
* Hash map with the set of key-value pairs that represent
* substitution data
* @return
*/
public static Boolean generateAndSendDocx(String templateName, Map<String,String> substitutionData) {
String templateLocation = TEMPLATE_DIRECTORY_ROOT + templateName;
String userTempDir = UUID.randomUUID().toString();
userTempDir = TEMPLATE_DIRECTORY_ROOT + userTempDir + "/";
try {
// Unzip .docx file
unzip(new File(templateLocation), new File(userTempDir));
// Change data
changeData(new File(userTempDir + MAIN_DOCUMENT_PATH), substitutionData);
// Rezip .docx file
zip(new File(userTempDir), new File(userTempDir + templateName));
// Send HTTP response
sendDOCXResponse(new File(userTempDir + templateName), templateName);
// Clean temp data
deleteTempData(new File(userTempDir));
}
catch (IOException ioe) {
System.out.println(ioe.getMessage());
return false;
}
return true;
}
/* PRIVATE METHODS */
/**
* Unzipps specified ZIP file to specified directory
*
* @param zipfile
* Source ZIP file
* @param directory
* Destination directory
* @throws IOException
*/
private static void unzip(File zipfile, File directory) throws IOException {
ZipFile zfile = new ZipFile(zipfile);
Enumeration<? extends ZipEntry> entries = zfile.entries();
while (entries.hasMoreElements()) {
ZipEntry entry = entries.nextElement();
File file = new File(directory, entry.getName());
if (entry.isDirectory()) {
file.mkdirs();
}
else {
file.getParentFile().mkdirs();
InputStream in = zfile.getInputStream(entry);
try {
copy(in, file);
}
finally {
in.close();
}
}
}
}
/**
* Substitutes keys found in target file with corresponding data
*
* @param targetFile
* Target file
* @param substitutionData
* Map of key-value pairs of data
* @throws IOException
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
private static void changeData(File targetFile, Map<String,String> substitutionData) throws IOException{
BufferedReader br = null;
String docxTemplate = "";
try {
br = new BufferedReader(new InputStreamReader(new FileInputStream(targetFile), "UTF-8"));
String temp;
while( (temp = br.readLine()) != null)
docxTemplate = docxTemplate + temp;
br.close();
targetFile.delete();
}
catch (IOException e) {
br.close();
throw e;
}
Iterator substitutionDataIterator = substitutionData.entrySet().iterator();
while(substitutionDataIterator.hasNext()){
Map.Entry<String,String> pair = (Map.Entry<String,String>)substitutionDataIterator.next();
if(docxTemplate.contains(pair.getKey())){
if(pair.getValue() != null)
docxTemplate = docxTemplate.replace(pair.getKey(), pair.getValue());
else
docxTemplate = docxTemplate.replace(pair.getKey(), "NEDOSTAJE");
}
}
FileOutputStream fos = null;
try{
fos = new FileOutputStream(targetFile);
fos.write(docxTemplate.getBytes("UTF-8"));
fos.close();
}
catch (IOException e) {
fos.close();
throw e;
}
}
/**
* Zipps specified directory and all its subdirectories
*
* @param directory
* Specified directory
* @param zipfile
* Output ZIP file name
* @throws IOException
*/
private static void zip(File directory, File zipfile) throws IOException {
URI base = directory.toURI();
Deque<File> queue = new LinkedList<File>();
queue.push(directory);
OutputStream out = new FileOutputStream(zipfile);
Closeable res = out;
try {
ZipOutputStream zout = new ZipOutputStream(out);
res = zout;
while (!queue.isEmpty()) {
directory = queue.pop();
for (File kid : directory.listFiles()) {
String name = base.relativize(kid.toURI()).getPath();
if (kid.isDirectory()) {
queue.push(kid);
name = name.endsWith("/") ? name : name + "/";
zout.putNextEntry(new ZipEntry(name));
}
else {
if(kid.getName().contains(".docx"))
continue;
zout.putNextEntry(new ZipEntry(name));
copy(kid, zout);
zout.closeEntry();
}
}
}
}
finally {
res.close();
}
}
/**
* Sends HTTP Response containing .docx file to Client
*
* @param generatedFile
* Path to generated .docx file
* @param fileName
* File name of generated file that is being presented to user
* @throws IOException
*/
private static void sendDOCXResponse(File generatedFile, String fileName) throws IOException {
FacesContext facesContext = FacesContext.getCurrentInstance();
ExternalContext externalContext = facesContext.getExternalContext();
HttpServletResponse response = (HttpServletResponse) externalContext
.getResponse();
BufferedInputStream input = null;
BufferedOutputStream output = null;
response.reset();
response.setHeader("Content-Type", "application/msword");
response.setHeader("Content-Disposition", "attachment; filename="" + fileName + """);
response.setHeader("Content-Length",String.valueOf(generatedFile.length()));
input = new BufferedInputStream(new FileInputStream(generatedFile), 10240);
output = new BufferedOutputStream(response.getOutputStream(), 10240);
byte[] buffer = new byte[10240];
for (int length; (length = input.read(buffer)) > 0;) {
output.write(buffer, 0, length);
}
output.flush();
input.close();
output.close();
// Inform JSF not to proceed with rest of life cycle
facesContext.responseComplete();
}
/**
* Deletes directory and all its subdirectories
*
* @param file
* Specified directory
* @throws IOException
*/
public static void deleteTempData(File file) throws IOException {
if (file.isDirectory()) {
// directory is empty, then delete it
if (file.list().length == 0)
file.delete();
else {
// list all the directory contents
String files[] = file.list();
for (String temp : files) {
// construct the file structure
File fileDelete = new File(file, temp);
// recursive delete
deleteTempData(fileDelete);
}
// check the directory again, if empty then delete it
if (file.list().length == 0)
file.delete();
}
} else {
// if file, then delete it
file.delete();
}
}
private static void copy(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
while (true) {
int readCount = in.read(buffer);
if (readCount < 0) {
break;
}
out.write(buffer, 0, readCount);
}
}
private static void copy(File file, OutputStream out) throws IOException {
InputStream in = new FileInputStream(file);
try {
copy(in, out);
} finally {
in.close();
}
}
private static void copy(InputStream in, File file) throws IOException {
OutputStream out = new FileOutputStream(file);
try {
copy(in, out);
} finally {
out.close();
}
}
}
Loop-performance notes specific to this pattern
The loop in the answer iterates in process. On a 2026 Office build, setting Application.ScreenUpdating = False and Application.Calculation = xlCalculationManual around a loop of this size typically cuts runtime by 40–70%. Re-enable both in the Exit handler.
When to Use It — vintage (14+ years old, pre-2013)
A top-10 Word VBA pattern — why it still holds up
Ranks #5th of 32 in the Word VBA archive. The only pattern ranked immediately above it is “How can Sweave users collaborate with Word users?” — compare both if you’re choosing between approaches.
What changed between 2012 and 2026
The answer is 14 years old. The Word VBA object model has been stable across Office 2013, 2016, 2019, 2021, 365, and 2024/2026 LTSC, so the pattern still compiles. Changes that might affect you: 64-bit API declarations (use PtrSafe), blocked macros in downloaded files (Mark-of-the-Web), and the shift toward Office Scripts for web-first workflows.