VendorIDtoNamesService.java

package services;

import java.io.File;
import java.io.IOException;
import java.io.Writer;
import java.util.Map;
import java.util.Scanner;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import model.VendorsEngine;


@WebServlet(
    name = "VendorIDtoNamesService",
    urlPatterns = {"/idToNameConcat"}
)
public class VendorIDtoNamesService extends HttpServlet {
  private static final long serialVersionUID = 1L;
       
  public VendorIDtoNamesService() {
    super();
  }

  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // We want to return a comma delimited list of the searched up names
    VendorsEngine engine = VendorsEngine.getInstance();
    Writer out = response.getWriter();
    HttpSession session = request.getSession(true);
    
    // Set the response type
    response.setContentType("text/plain");

    // If session doesn't have name, set it to empty string	
    if (session.getAttribute("name") == null) {
      session.setAttribute("name", "");
    }

    String concat_name = (String) session.getAttribute("name");	
    Map<String, String[]> parameters = request.getParameterMap();
    String resp;

    String idAddress = getInitParameter("idAddress");
    
    if (idAddress == null) {
      System.out.println(getInitParameter("idAddressRegister"));
      try (Scanner in = new Scanner(new File(getInitParameter("idAddressRegister")))) {
        idAddress = in.nextLine();
      }
    } else {
      if (getInitParameter("idPort") != null) {
        idAddress += ":" + getInitParameter("idPort");
      }
    }

    String[] idParts = idAddress.split(":"); 
    String   idHost  = idParts[0];
    int      idPort  = Integer.parseInt(idParts[1]);

    // If given id
    if (parameters.containsKey("id")) {
      // Get name from id
      String id = request.getParameter("id");
      String name = engine.runIDtoName(id, idHost, idPort);
        
      // Do not append to comma separated 'list' if id not found
      if (name.startsWith("not found") || 
          name.startsWith("Do not understand: ") || 
          name.startsWith("Failed to complete connection with ID") ||
          name.startsWith("Failed to get ID service's host and port addresses")) {

        resp = name + "\n" + "List of names: " + concat_name;
      } else {
        // Add to list of names if found
        String new_name;
        if (concat_name.equals("")) {
          new_name = name; 
        } else {
          new_name = concat_name + ", " + name; 					
        }
        session.setAttribute("name", new_name);
        resp = "List of names: " + new_name;
        out.write(resp);
      }
    }
  }

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