import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
/**
* This servlet modifies a specified XHTML document so that its ol
* elements are collapsible.
*/
public class Hw7 extends HttpServlet
{
/**
* Handle get request. It should contain 'targetDoc' parameter
* which is the URL of the XHTML document to be modified.
*/
public void doGet (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
// Set the HTTP content type in response header
response.setContentType("text/html; charset=\"UTF-8\"");
// Obtain a PrintWriter object for creating the body
// of the response and output initial portion of XHTML response
PrintWriter servletOut = response.getWriter();
// Get the URL of the target document
String targetDocURL = request.getParameter("targetDoc");
if (targetDocURL == null) {
servletOut.println(
" \n" +
" \n" +
" \n" +
" \n" +
" MakeolCollapse.java error \n" +
" \n" +
" \n" +
" \n" +
" Error: targetDoc parameter missing.
\n" +
" \n" +
"");
}
else {
// Input the document as a DOM tree
try {
DocumentBuilderFactory docBuilderFactory =
DocumentBuilderFactory.newInstance();
DocumentBuilder parser = docBuilderFactory.newDocumentBuilder();
Document document = parser.parse(targetDocURL);
// Add script element
Node head = document.getElementsByTagName("head").item(0);
Element script = document.createElement("script");
head.appendChild(script);
script.setAttribute("type", "text/javascript");
script.setAttribute("src", "../BlockCollapse.js");
// Add "Click to collapse" buttons before all ol
// elements
NodeList ols = document.getElementsByTagName("ol");
for (int i=0; i