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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("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[i]; 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); } }
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