AdminPanelHandler.java

package ru.semiot.platform.apigateway.config;

import ru.semiot.platform.apigateway.utils.Credentials;
import ru.semiot.platform.apigateway.utils.DataBase;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

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

/**
 * @author Daniil Garayzuev <garayzuev@gmail.com>
 */
@WebServlet("/config/AdminPanel")
public class AdminPanelHandler extends HttpServlet {

  @Inject
  DataBase db;
  volatile List<Credentials> credentials;

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    String s = req.getQueryString();
    if (s != null && s.contains("logout")) {
      resp.setHeader("Cache-Control", "no-cache, no-store");
      resp.setHeader("Pragma", "no-cache");
      resp.setHeader("Expires", new java.util.Date().toString());
      if (req.getSession(false) != null) {
        req.getSession(false).invalidate();// remove session.
      }
      req.logout();
      resp.sendRedirect("/");
    }
    synchronized (this) {
      credentials = db.getAllUsers();
    }
    ;
    req.setAttribute("credentials", credentials);
    req.getRequestDispatcher("/configuration/AdminPanel").forward(req, resp);
  }

  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {

    if (req.getParameter("save") != null) {
      Map m = req.getParameterMap();
      String[] ids = (String[]) m.get("id");
      String[] logins = (String[]) m.get("login");
      String[] passwords = (String[]) m.get("password");
      String[] roles = (String[]) m.get("role");
      List<Credentials> newList = new ArrayList<>();
      Credentials c;
      for (int i = 0; i < ids.length; i++) {

        c = new Credentials(Integer.parseInt(ids[i]), logins[i], passwords[i],
            (i == 0) ? "admin" : roles[i]);
        if (c.getLogin().isEmpty() || c.getLogin().contains(" ")
            || !db.isUniqueLogin(c.getLogin(), c.getId())) {
          if (credentials.contains(c)) {
            newList.add(credentials.get(credentials.indexOf(c)));
          }
          continue;
        }
        newList.add(c);
        if (credentials.contains(c)) {
          if (c.needUpdate(credentials.get(credentials.indexOf(c)))) {
            if (!db.updateUser(c)) {
              newList.remove(c);
            }
          }
        } else if (db.addUser(c) == null) {
          newList.remove(c);
        }
      }
      for (Credentials q : credentials) {
        if (!newList.contains(q)) {
          db.removeUser(q.getId());
        }
      }
      resp.sendRedirect("/config/AdminPanel");
    }
  }
}