coloring certain keywords in itext

Question

The program has to turn a existing Java file (.java) into a PDF. But inside of the PDF, certain keywords have to be colored (int, double, new, ...) like in Netbeans (which I am using). So until now I turned the java file to a string and colored the keywords inside of the string with the ANSI color. But when transitioning to the PDF I can't keep the keywords colored.

Here is my marking/coloring of the keywords in the String:

public static String markKeywords(String doc, String keywords){

    String[] keywordsarr = keywords.split(",");
    
    for(int i = 0; i<keywordsarr.length;i++){
        String old = " " + keywordsarr[i] + "" ;
        String neu = " \u001B[34m" + keywordsarr[i] + "\u001B[0m";
        doc = doc.replace(old,neu);
    }
    return doc;
}

And here the transitioning to the pdf:

public static void createPDF(String doc,String loc){
    try{
        //Font font = new Font(FontFamily.COURIER, 13, Font.NORMAL, BaseColor.BLACK);
        //Create Font with Encoding
        BaseFont fontstd = BaseFont.createFont("C:\\Windows\\Fonts\\cour.ttf", BaseFont.WINANSI,
        BaseFont.EMBEDDED);
        Font font_std = new Font(fontstd, 13);
        
        //Saving pdf file in the same folder
        String targetloc = loc.replace(".java", ".pdf"); 
        
        //creating pdf
        Document document = new Document();            
        PdfWriter.getInstance(document, new FileOutputStream(targetloc));
        
        document.open();
        Paragraph p = new Paragraph();
        
        p.add(new Chunk(doc, font_std));
        document.add(p);
        document.close();
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

The scripts I have to turn into PDFs are very basic, consisting only of a main and a few other methods. I also haven't found something in itext like String.replace()" which would be really great if I could change the color of the keywords that way in itext.

Answer 1

Thank you to El-Dow for the inspiration of the code. I added some Improvements, so that the lines aren´t overlapping. i also added some conditions for splitting the String, for Excample on "double[]" only "double" has to be colourded and not the Brackets.

public static void createPDF(String doc,String loc){
    try{
        //Font font = new Font(FontFamily.COURIER, 13, Font.NORMAL, BaseColor.BLACK);
         // Font for regular text
        BaseFont fontStd = BaseFont.createFont("C:\\Windows\\Fonts\\cour.ttf", BaseFont.WINANSI, BaseFont.EMBEDDED);
        Font fontRegular = new Font(fontStd, 13);

        // Font for keyword text
        Font fontKeyword = new Font(fontStd, 13, Font.BOLD, new BaseColor(0, 0, 255)); // blue color
        
        //Saving pdf file in the same folder
        String targetloc = loc.replace(".java", ".pdf"); 
        
        //creating pdf
        Document document = new Document();            
        PdfWriter.getInstance(document, new FileOutputStream(targetloc));            
        document.open();
        
        //Split the document into words          
        String[] words = doc.split("(?=\\[)|(?=\\.)|(?<=\\()|(?=\\=)|(?<=\\n+)|(?= )|(?<= )");
        //Split only by keywords doesn´t work, because some contain others "do" and "double"
        
        // Add each word to the document as a chunk with the appropriate font
        for (String word : words) {
            if (isKeyword(word)) {
                Chunk chunk = new Chunk(word, fontKeyword);
                document.add(new Phrase(chunk));
            } else {
                Chunk chunk = new Chunk(word, fontRegular);
                document.add(new Phrase(chunk));
            }
        }

        document.close();
        
    }catch(Exception e){
        e.printStackTrace();
    }
}

private static boolean isKeyword(String word){
    String keywords = "abstract,continue,for,new,switch,assert,default,if,package,synchronized,boolean,goto,privat,this,break,double,implements,protected,throw,byte,else,import,public,throws,case,enum,instanceof,return,transient,catch,extends,int,short,try,char,final,interface,static,void,class,finally,long,strictfp,volatile,const,float,native,super,while,do";
    String[] keywordsarr = keywords.split(",");
    for (String keyword : keywordsarr){
        if(keyword.equals(word)){
            return true;
        }
    }
    return false;        
}