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Rendering big Post Script file with Ghost4J in Java

i made a Java application whose purpose is to offer a Print Preview for PS files.
My program uses Ghostscript and Ghost4J to load the Post Script file and produces a list of Images (one for each page) using the SimpleRenderer.render method. Then using a simple JList i show only the image corresponding to the page the user selected in JList.
This worked fine until a really big PS file occurred, causing an OutOfMemoryError when executing the code
PSDocument pdocument = new PSDocument(new File(filename));
I know that is possibile to read a file a little at a time using InputStreams, the problem is that i can't think of a way to connect the bytes that i read with the actual pages of the document.
Example, i tried to read from PS file 100 MB at a time
int buffer_size = 100000000;
byte[] buffer = new byte[buffer_size];
FileInputStream partial = new FileInputStream(filename);
partial.read(buffer, 0, buffer_size);
document.load(new ByteArrayInputStream(buffer));
SimpleRenderer renderer = new SimpleRenderer();
//how many pages do i have to read?
List<Image> images = renderer.render(document, firstpage ??, lastpage ??);
Am i missing some Ghost4J functionality to read partially a file?
Or has someone other suggestions / approaches about how to solve this problem in different ways?
I am really struggling

I found out I can use Ghost4J Core API to retrieve from a Post Script file a reduced set of pages as Images.
Ghostscript gs = Ghostscript.getInstance();
String[] gsArgs = new String[9];
gsArgs[0] = "-dQUIET";
gsArgs[1] = "-dNOPAUSE";
gsArgs[2] = "-dBATCH";
gsArgs[3] = "-dSAFER";
gsArgs[4] = "-sDEVICE=display";
gsArgs[5] = "-sDisplayHandle=0";
gsArgs[6] = "-dDisplayFormat=16#804";
gsArgs[7] = "-sPageList="+firstPage+"-"+lastPage;
gsArgs[8] = "-f"+filename;
//create display callback (capture display output pages as images)
ImageWriterDisplayCallback displayCallback = new ImageWriterDisplayCallback();
//set display callback
gs.setDisplayCallback(displayCallback);
//run PostScript (also works with PDF) and exit interpreter
try {
gs.initialize(gsArgs);
gs.exit();
Ghostscript.deleteInstance();
} catch (GhostscriptException e) {
System.out.println("ERROR: " + e.getMessage());
e.printStackTrace();
}
return displayCallback.getImages(); //return List<Images>
This solve the problem of rendering page as images in the preview.
However, i could not find a way to use Ghost4J to know total number of pages of PS file (in case the file is too big for opening it with Document.load()).
So, i am still here needing some help

HWPF-POI:The table insert into doc with poi hwpf is not visible

I want to insert a table at a specific position with poi, the table is generated, but I find this table is not visible.
The generated table in doc is visible when previewing or editing this doc with macOS and its text tool, POI can read the table and content, too. I plan to upload 4 pictures to display the process, but I can only post 2 images, sorry for that.
#Test
public void exportDoc() throws Exception {
FileInputStream readFile = new FileInputStream(new File(readDoc));
FileOutputStream replaceFile = new FileOutputStream(new File(replaceDoc));
HWPFDocument document = new HWPFDocument(readFile);
Table table = WordUtil.insertNewTable(document,"${table}");
insertTableInDoc(table);
document.write(replaceFile);
readFile.close();
replaceFile.close();
}
private Table insertNewTable(HWPFDocument doc, String sourceValue) {
Range range = doc.getRange();
Table table = null;
for (int i = 0; i < range.numSections(); ++i) {
Section s = range.getSection(i);
for (int x = 0; x < s.numParagraphs(); x++) {
Paragraph p = s.getParagraph(x);
if (p.text().contains(sourceValue)) {
//remove target text
range.replaceText(sourceValue, "");
table = p.insertTableBefore((short) 3, 3);
return table;
}
}
}
return table;
}
private void insertTableInDoc(Table table) {
int count = 1;
for (int rowNum = 0; rowNum < table.numRows(); rowNum++) {
TableRow tableRow = table.getRow(rowNum);
for (int colNum = 0; colNum < tableRow.numCells(); colNum++) {
TableCell cell = tableRow.getCell(colNum);
Paragraph paragraph = cell.getParagraph(0);
CharacterRun characterRun = paragraph.getCharacterRun(0);
characterRun.insertBefore("number: " + count++);
}
}
}
PS:
I am sure this is not microsoft for mac 's problem, the generate table in doc at windows platform is not visible, too.
(First time to ask question, if anything wrong or my expression is not clear, please let me know and I will modify it without delay. Thanks)

With the current state of the HWPF project, you likely are out of luck when trying to insert content into a .doc file. Your best bet is to use a different format (docx).
I did not look at HWPF for the past year, so I may be wrong here regarding the current state of HWPF:
Some years ago I was developing a custom HWPF library for a client. The major goal for that custom library was the ability to modify .doc files and that Word can process the modified files correctly. Hence I know in how many levels modifying a .doc file can fail in the end. The public HWPF library is not able to handle many aspects of the .doc file format when it comes to modification (textboxes, two-byte character ranges, shape files, nested tables, ... to name a few).
To handle modification correctly, all the "features" of the specific .doc file must be supported by the library. So when there are shapes in the .doc file, HWPF must adjust the position tables of the shapes even when a simple text snippet is inserted and the shapes are not touched. If shapes are not handled, Word will crash when opening the output file.
So if you can, use docx or rtf. If it is an option, you might try one of the commercial libraries which are able to handle .doc files.

JAVA POI DOCX replace text in paragraph

Hi i m trying to replace some text in a docx file, but i got problemes with text to be replaced that can be on multiple runs. So i tried this : but it erase everything in the document :/
private void replaceText(XWPFParagraph p, String target, String replacement) {
if (p.getRuns() != null) {
String paragraph = p.getText();
for (int i = 0; i < p.getRuns().size(); i++) {
p.removeRun(i);
}
paragraph = paragraph.replace(target, replacement);
XWPFRun r = new XWPFRun(CTR.Factory.newInstance(), p);
r.setText(paragraph, 0);
}
}

It will surely erase everything because you are removing all the runs in the paragraph. Point to understand here is that the text in the paragraph is stored inside the runs. What getText() does is it returns all the text in all the runs of the paragraph.
Removing all runs and adding just one new run will surely disrupt the font and alignment of the text
You are removing all the runs and then adding one run with the replaced text.
I believe this is not what you wish to achieve.
Just loop over the runs and replace the text inside them.

For one of my projects I chose a different route, I work on the underlying XML data and do a search/replace there which usually works quite nicely.
See https://github.com/centic9/poi-mail-merge for the details, but basically I fetch the CTBody low-level item via
CTBody body = doc.getDocument().getBody();
And then read the full XML body text
// read the current full Body text
String srcString = body.xmlText();
then do the replacements.
Finally I create a new CTBody item with the new contents via
CTBody makeBody = CTBody.Factory.parse(resultStr);
See https://github.com/centic9/poi-mail-merge/blob/master/src/main/java/org/dstadler/poi/mailmerge/MailMerge.java#L81 for the full code-details as there are a few more things that are handled to make it work nicely.

ItextSharp - diacritic chars

i reading pdf documents via ItextSharp library.
But these documents is in Czech language which use diacritic (ř ě ž š č etc.)
How I can read this chars? Any idea? Or, is some solution for replacing this chars for normal r e z s c ?
This is code in my method. Thanks
PdfReader reader = new PdfReader("M:/ShareDirs_KSP/RDM_Debtors/DMS_PROD/" + src);
// we can inspect the syntax of the imported page
String text = new String();
for (int page = 1; page <= 1; page++) {
text += PdfTextExtractor.getTextFromPage(reader, page);
}
reader.close();

I have written a small proof of concept that parses the file czech.pdf. This file contains several characters with diacritics. It was created in answer to the following question: Can't get Czech characters while generating a PDF
The text is stored in the file twice: once using a simple font, once using a composite font. In my proof of concept (named ParseCzech), I parse this PDF to a file encoded using UTF-8 (UNICODE):
public void parse(String filename) throws IOException {
PdfReader reader = new PdfReader(filename);
FileOutputStream fos = new FileOutputStream(DEST);
for (int page = 1; page <= 1; page++) {
fos.write(PdfTextExtractor.getTextFromPage(reader, page).getBytes("UTF-8"));
}
fos.flush();
fos.close();
}
The result is the file czech.txt:
As you can see from the screen shot, the text is extracted correctly (but make sure that the viewer you use knows that the file is encoded as UTF-8, otherwise you may see strange characters instead of the actual text).
Note that some PDFs do not allow text to be extracted correctly. This is explained in the following video: http://www.youtube.com/watch?v=wxGEEv7ibHE
Please share your PDF so that people on StackOverflow can check whether you don't succeed to extract text because of an error in your code, or whether you don't succeed because the PDF doesn't allow you to extract the text.

java.awt.font to com.itextpdf.text.fontfactory

I'm doing an application that will putting together a pdf with iText library and among other things the source (typography) is selected by jfontchooser (font selector).
The problem is that jfontchooser returns the name of the source. If I select Times New Roman returns exactly "Times New Roman"
But itext needs "Times- Roman" and I cannot find a way how to translate it.
I would like to translate java.awt.font to com.itextpdf.text.fontfactory
the next attempt so get saved in a txt source (of course I put static data to be understood. )
String fuenteNombre = "Times New Roman";
int fuenteSize = 14;
int fuenteEstilo = 1;
Color fuenteColor = new Color(0,0,0,255);
this.fuenteTitulo = FontFactory.getFont(fuenteNombre,
fuenteSize,
fuenteEstilo,
fuenteColor);

i solve the problem, using defaultFontMapper.. see in http://www.forosdelweb.com/f45/problema-con-font-itext-1111176/#post4647340