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            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(&quot;searchString&quot;);if ((searchString == null) //(searchString.length() == 0)) {reportProblem(response, &quot;Missing search string.&quot;);return;}// The URLEncoder changes spaces to &quot;+&quot; signs and other// non-alphanumeric characters to &quot;%XY&quot;, 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(&quot;numResults&quot;);if ((numResults == null) //(numResults.equals(&quot;0&quot;)) //(numResults.length() == 0)) {numResults = &quot;10&quot;;}String searchEngine =request.getParameter(&quot;searchEngine&quot;);if (searchEngine == null) {reportProblem(response, &quot;Missing search engine name.&quot;);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, &quot;Unrecognized search engine.&quot;);}private void reportProblem(HttpServletResponse response,String message)throws IOException {response.sendError(response.SC_NOT_FOUND,&quot;<H2>&quot; + message + &quot;</H2>&quot;);}public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}