Java tutorial
/* * Copyright 2012 the original author or authors. * * 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 us.repasky.microblog.controllers; import java.security.Principal; import java.util.Arrays; import java.util.Date; import java.util.List; import java.util.Map; import javax.validation.Valid; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.domain.Page; import org.springframework.stereotype.Controller; import org.springframework.validation.BindingResult; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import us.repasky.microblog.domain.BlogUser; import us.repasky.microblog.domain.Post; import us.repasky.microblog.dto.UserPostDto; import us.repasky.microblog.services.UserService; /** * These are operations involving users, such as logging in, registering, and * showing/creating posts. * * @author Drew Repasky */ @Controller public class UserController { private static final Logger logger = LoggerFactory.getLogger(UserController.class); private static final String ERROR_MESSAGE = "errorMessage"; @Autowired private UserService userService; public void setUserService(UserService userService) { this.userService = userService; } /** * Parse an integer from a String. Returns zero when it's not an integer and * when it's less than zero. */ protected Integer readPageNumber(final String page) { Integer pageNumber = 0; try { pageNumber = Integer.valueOf(page); } catch (NumberFormatException ex) { // it's safe to eat this exception, since we correct for non-integers logger.info("Page number input was invalid: " + page); } return (pageNumber >= 0) ? pageNumber : 0; } @RequestMapping(value = "/login", method = RequestMethod.GET) public String login() { logger.trace("executing inside UserController login()"); return "login"; } @RequestMapping(value = "/register", method = RequestMethod.GET) public String register(Map<String, Object> model) { logger.trace("executing inside UserController register()"); if (!model.containsKey("blogUser")) { model.put("blogUser", new BlogUser()); } return "register"; } @RequestMapping(value = "/error", method = RequestMethod.GET) public String error() { logger.trace("executing inside UserController error()"); return "error"; } @RequestMapping(value = "/errorNotFound", method = RequestMethod.GET) public String errorNotFound() { logger.trace("executing inside UserController errorNotFound()"); return "errorNotFound"; } @RequestMapping(value = "/createUser", method = RequestMethod.POST) public String createUser(@Valid BlogUser blogUser, BindingResult result, Map<String, Object> model) { logger.trace("executing inside UserController createUser()"); String view = ""; if (!result.hasErrors()) { String username = blogUser.getUsername(); String password = blogUser.getPassword(); if (userService.userExists(username)) { view = "invalid"; model.put(ERROR_MESSAGE, "Could not register the username \"" + username + "\" because it has already been taken by another user."); } else { String errorMessage = userService.registerUser(username, password); if (StringUtils.isBlank(errorMessage)) { view = "login"; model.put("message", "Thank you for registering, " + username + ". You can now login using your new account."); } else { view = "error"; model.put(ERROR_MESSAGE, errorMessage); } } } else { logger.debug("Registering new BlogUser failed validation."); model.put("blogUser", blogUser); view = register(model); } return view; } @RequestMapping(value = "/", method = RequestMethod.GET) public String showPostsFromFollowers(@RequestParam(defaultValue = "0") final String page, Map<String, Object> model, final Principal principal) { logger.trace("executing inside UserController showPostsFromFollowers()"); String myUsername = principal.getName(); Page<Post> posts = userService.getAllFollowersPostsForUser(myUsername, readPageNumber(page)); model.put("posts", posts); if (!model.containsKey("post")) { model.put("post", new Post()); } return "createPost"; } @RequestMapping(value = "/", method = RequestMethod.POST) public String doMessagePost(@Valid Post post, BindingResult result, @RequestParam(defaultValue = "0") final String page, Map<String, Object> model, final Principal principal) { logger.trace("executing inside UserController doMessagePost()"); String view = ""; String myUsername = principal.getName(); if (!result.hasErrors()) { String errorMessage = userService.createPost(myUsername, post); if (StringUtils.isBlank(errorMessage)) { model.put("message", "Post created successfully"); view = "createPost"; } else { model.put(ERROR_MESSAGE, errorMessage); view = "error"; } } else { logger.debug("Posted message failed validation."); model.put("post", post); view = "createPost"; } showPostsFromFollowers(page, model, principal); return view; } /** * Return all the follower's posts for the logged-in user, in JSON format. */ @RequestMapping(value = "/livePosts", method = RequestMethod.GET, produces = "application/json") @ResponseBody public List<UserPostDto> getPosts(final Long createdAfter, final Principal principal) { logger.trace("executing inside UserController getPosts()"); logger.debug("milliseconds: " + createdAfter); Date createdAfterDate = new Date(createdAfter); logger.debug("date: " + createdAfterDate); return userService.getFollowersPostsForUser(principal.getName(), createdAfterDate); } @RequestMapping(value = "/posts", method = RequestMethod.GET) public String showPostsForOneUser(final String username, @RequestParam(defaultValue = "0") final String page, Map<String, Object> model) { logger.trace("executing inside UserController showPostsForOneUser()"); String view = "posts"; if (!StringUtils.isBlank(username)) { if (userService.userExists(username)) { Page<Post> posts = userService.getAllPostsForUsers(Arrays.asList(username), readPageNumber(page)); model.put("posts", posts); model.put("username", username); } else { model.put(ERROR_MESSAGE, "The username \"" + username + "\" does not exist."); view = "invalid"; } } return view; } }