Java Open pdf file in new browser window

Question

I want to display a pdf file in a new tab of the browser of client side.

I have created a servlet class in order to display the pdf File, I'm new in Java and i don't know how to use the class I've crerated, and if the class is right.

I work with Java on windows with Tomcat.

The servlet code:

public class DisplayPdf extends HttpServlet implements Servlet {

private static final long serialVersionUID = 1L;

protected void doGet(HttpServletRequest request, HttpServletResponse response) 
        throws ServletException, IOException {
    processRequest(request, response);
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) 
        throws ServletException,
        IOException {
    processRequest(request, response);
}

private void processRequest(HttpServletRequest request, HttpServletResponse response) 
        throws ServletException,
        IOException {
        File file = new File("test.pdf");
        InputStream inputStream = getServletContext().getResourceAsStream("/WEB-INF/resources/test.pdf");
        OutputStream outputStream = new FileOutputStream(file);
        byte[] buffer = new byte[1024];
        int length;
        while ((length = inputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }
        outputStream.close();
        inputStream.close();
}

}

How can I call this servlet and use it from the Java Webapp?

Answer 1

This has actually nothing (or just very little) to do with servlets nor any other server-side technology, opening new window/tab or save dialog is fully in browser's competence. All you can do server-side is to set proper HTTP headers to your response, eg

response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "inline; filename=\"My.pdf\"");

The inline part of the Content-Disposition header tells browser, that it can display the file inline, if it is able to, attachment would force download.

You can force opening new tab/window from the HTML, where the file is linked, using eg

<a href="#" onclick="window.open('My.pdf', '_blank', 'fullscreen=yes'); return false;">My PDF</a>

See window.open() documentation for more details.