/**
 * Copyright 2012 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.appengine.demos.guestbook;

import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

import java.io.IOException;
import java.util.Properties;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class GuestbookServlet extends HttpServlet {
  @Override
  public void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws IOException {
    if (req.getParameter("testing") == null) {
      resp.setContentType("text/plain");
      resp.getWriter().println("Hello, this is a testing servlet. \n\n");
      Properties p = System.getProperties();
      p.list(resp.getWriter());

    } else {
      UserService userService = UserServiceFactory.getUserService();
      User currentUser = userService.getCurrentUser();

      if (currentUser != null) {
        resp.setContentType("text/plain");
        resp.getWriter().println("Hello, " + currentUser.getNickname());
      } else {
        resp.sendRedirect(userService.createLoginURL(req.getRequestURI()));
      }
    }
  }
}

/**
 * Copyright 2012 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.appengine.demos.guestbook;

import com.google.appengine.api.users.User;
import com.google.appengine.api.users.UserService;
import com.google.appengine.api.users.UserServiceFactory;

import java.io.IOException;
import java.util.Properties;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class GuestbookServlet extends HttpServlet {
  @Override
  public void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws IOException {
    if (req.getParameter("testing") == null) {
      resp.setContentType("text/plain");
      resp.getWriter().println("Hello, this is a testing servlet. \n\n");
      Properties p = System.getProperties();
      p.list(resp.getWriter());
      // Athicha added comment here.
    } else {
      UserService userService = UserServiceFactory.getUserService();
      User currentUser = userService.getCurrentUser();

      if (currentUser != null) {
        resp.setContentType("text/plain");
        resp.getWriter().println("Hello, " + currentUser.getNickname());
      } else {
        resp.sendRedirect(userService.createLoginURL(req.getRequestURI()));
      }
    }
  }
}

Test adding comment