XSLFTextShape title2 = slide2.getPlaceholder(0);
title2.setText("Second Title");
XSLFTextShape body2 = slide2.getPlaceholder(1);
body2.clearText(); // unset any existing text
body2.addNewTextParagraph().addNewTextRun().setText("First paragraph");
body2.addNewTextParagraph().addNewTextRun().setText("Second paragraph");
body2.addNewTextParagraph().addNewTextRun().setText("Third paragraph");