package coreservlets;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.net.*;

public class SearchEngines extends HttpServlet {

public void doGet(HttpServletRequest request,

HttpServletResponse response)

throws ServletException, IOException {

String searchString = request.getParameter("searchString");

if ((searchString == null) //

(searchString.length() == 0)) {

reportProblem(response, "Missing search string.");

return;

}

// The URLEncoder changes spaces to "+" signs and other

// non-alphanumeric characters to "%XY", where XY is the

// hex value of the ASCII (or ISO Latin-1) character.

// Browsers always URL-encode form values, so the

// getParameter method decodes automatically. But since

// we're just passing this on to another server, we need to

// re-encode it.

searchString = URLEncoder.encode(searchString);

String numResults = request.getParameter("numResults");

if ((numResults == null) //

(numResults.equals("0")) //

(numResults.length() == 0)) {

numResults = "10";

}

String searchEngine =

request.getParameter("searchEngine");

if (searchEngine == null) {

reportProblem(response, "Missing search engine name.");

return;

}

SearchSpec[] commonSpecs = SearchSpec.getCommonSpecs();

for(int i=0; i<commonSpecs.length; i++) {

SearchSpec searchSpec = commonSpecs;

if (searchSpec.getName().equals(searchEngine)) {

String url =

searchSpec.makeURL(searchString, numResults);

response.sendRedirect(url);

return;

}

}

reportProblem(response, "Unrecognized search engine.");

}

private void reportProblem(HttpServletResponse response,

String message)

throws IOException {

response.sendError(response.SC_NOT_FOUND,

"<H2>" + message + "</H2>");

}

public void doPost(HttpServletRequest request,

HttpServletResponse response)

throws ServletException, IOException {

doGet(request, response);

}

}