Q:

PDFBox Overlapped Text

I have Implemented an algorithm to draw text on pages using PDFBox library for Android.  The problem is whenever I add a new page the text is overlapped like shown on the image below.  I am sure i am using the PDPageContentStream.newLine() method but the result is not as expected. 
Am I missing something else ? 
Here is my code snippet 
PDPage page1 = new PDPage();
getInstance().getAnnexe().addPage(page1);
PDPageContentStream contentStream1 = new 
PDPageContentStream(getInstance().getAnnexe(), page1, true, true);
contentStream1.beginText();
contentStream1.newLineAtOffset(100F, 650F);
contentStream1.setFont(font, fontSize);
printMultipleLines(subSet, contentStream1);
contentStream1.endText();
contentStream1.close();

And this is the printMultipleLines() Method
private void printMultipleLines(ArrayList<String> lines, PDPageContentStream contentStream) {
    try {
        for (String line :
                lines) {
            if (line.length() > 110) {
                // Print line as 2 lines
                contentStream.showText(line.substring(0, 90));
                contentStream.newLine();
                contentStream.showText(line.substring(90, line.length()));
            } else
                // Print line as a whole
                contentStream.showText(line);
            // Print Carriage Return
            contentStream.newLine();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

A:

Thank to @TilmanHausherr the problem was with the TL operator.  Each newly created page had TL equal to zero amount of user default units.  I just had to set the Text Leading offset. 
Here is the updated code :
PDPage page1 = new PDPage();
getInstance().getAnnexe().addPage(page1);
PDPageContentStream contentStream1 = new 
PDPageContentStream(getInstance().getAnnexe(), page1, true, true);
// Set the Text Leading (TL operator) here!!!! 
contentStream1.setLeading(12);
contentStream1.beginText();
contentStream1.newLineAtOffset(100F, 650F);
contentStream1.setFont(font, fontSize);
printMultipleLines(subSet, contentStream1);
contentStream1.endText();
contentStream1.close();

All thanks and credits goes to @ TilmanHausherr for his fast and accurate answer.