Update PDF using pdfBox - pdf

Question

I would like to ask if having a PDF it is possible, using pdfbox libraries, to update it at a specific point.
I am trying to use a solution already online but seems the gettoken() method does not enter code heresection the words properly to allow me to find the part I would like to modify.
This is the code(Groovy):
for( int i = 0; i < dataContext.getDataCount(); i++ ) {
InputStream is = dataContext.getStream(i);
Properties props = dataContext.getProperties(i);
String searchString= "Hours worked";
String replacement = "Hours worked: 2";
File file = new File("\\\\****\\UKDC\\GFS\\PRE\\PREPROD\\Alchemer\\Template\\***.pdf");
PDDocument doc = PDDocument.load(file);
for ( PDPage page : doc.getPages() )
{
PDFStreamParser parser = new PDFStreamParser(page);
parser.parse();
List tokens = parser.getTokens();
logger.info("in Page");
for (int j = 0; j < tokens.size(); j++)
{
logger.info("tokens:"+tokens[j]);
Object next = tokens.get(j);
//logger.info("in Object");
if (next instanceof Operator)
{
Operator op = (Operator) next;
String pstring = "";
int prej = 0;
//Tj and TJ are the two operators that display strings in a PDF
if (op.getName().equals("Tj"))
{
logger.info("in Tj");
// Tj takes one operator and that is the string to display so lets update that operator
COSString previous = (COSString) tokens.get(j - 1);
String string = previous.getString();
logger.info("previousString:"+string);
string = string.replaceFirst(searchString, replacement);
previous.setValue(string.getBytes());
} else
if (op.getName().equals("TJ"))
{
logger.info("in TJ:"+ op.getName());
COSArray previous = (COSArray) tokens.get(j - 1);
logger.info("previous:"+previous);
for (int k = 0; k < previous.size(); k++)
{
Object arrElement = previous.getObject(k);
if (arrElement instanceof COSString)
{
COSString cosString = (COSString) arrElement;
String string = cosString.getString();
logger.info("string:"+string);
if (j == prej || string.equals(" ") || string.equals(":") || string.equals("-")) {
pstring += string;
} else {
prej = j;
pstring = string;
}
}
}
logger.info("pstring:"+pstring);
if (searchString.equals(pstring.trim()))
{
logger.info("in searchString");
COSString cosString2 = (COSString) previous.getObject(0);
cosString2.setValue(replacement.getBytes());
int total = previous.size()-1;
for (int k = total; k > 0; k--) {
previous.remove(k);
}
}
}
}
}
logger.info("in updatedStream");
// now that the tokens are updated we will replace the page content stream.
PDStream updatedStream = new PDStream(doc);
OutputStream out = updatedStream.createOutputStream(COSName.FLATE_DECODE);
ContentStreamWriter tokenWriter = new ContentStreamWriter(out);
tokenWriter.writeTokens(tokens);
logger.info("in tokenWriter");
out.close();
page.setContents(updatedStream);
doc.save("\\\\***\\UKDC\\GFS\\PRE\\PREPROD\\Alchemer\\***1.pdf");
}
Executing the code I am trying to search "Hours worked" String and update with
"Hours worked: 2"
There are 2 questions:
1.When I execute and check the logs can see the Tokens are not created properly:
enter image description here
enter image description here
So are created two different COSArrays meantime I have all in one Line:
enter image description here
and this can be a problem if I have to search a specific word.
When it find the word it seems it is working but it apply a strange char:
enter image description here
So Here 2 questions:
How to manage to specify the token behaviour (or maybe for the parser) to get an entire phrase in the same token until a special char happen?
Hot to format the new char in the new PDF?
Hope you can help me, thanks for your support.