Create servlet to change password

src/main/java/codeu/controller/ChangePasswordServlet.java

@@ -0,0 +1,103 @@
+// Copyright 2017 Google Inc.
+//
+// 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 codeu.controller;
+
+import codeu.model.data.User;
+import codeu.model.store.basic.MessageStore;
+import codeu.model.store.basic.UserStore;
+import java.io.IOException;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.mindrot.jbcrypt.BCrypt;
+
+/** Servlet class responsible for the change password page. */
+public class ChangePasswordServlet extends HttpServlet {
+
+  /** Store class that gives access to Users and Messages. */
+  private UserStore userStore;
+
+  private MessageStore messageStore;
+
+  /**
+   * Set up state for handling password-changing-related requests. This method is only called when
+   * running in a server, not when running in a test.
+   */
+  @Override
+  public void init() throws ServletException {
+    super.init();
+    setMessageStore(MessageStore.getInstance());
+    setUserStore(UserStore.getInstance());
+  }
+
+  /**
+   * Sets the MessageStore used by this servlet. This function provides a common setup method for
+   * use by the test framework or the servlet's init() function.
+   */
+  void setMessageStore(MessageStore messageStore) {
+    this.messageStore = messageStore;
+  }
+
+  /**
+   * Sets the UserStore used by this servlet. This function provides a common setup method for use
+   * by the test framework or the servlet's init() function.
+   */
+  void setUserStore(UserStore userStore) {
+    this.userStore = userStore;
+  }
+
+  /**
+   * This function fires when a user requests the /changepassword URL. It simply forwards
+   * the request to changepassword.jsp.
+   */
+  @Override
+  public void doGet(HttpServletRequest request, HttpServletResponse response)
+      throws IOException, ServletException {
+    request.getRequestDispatcher("/WEB-INF/view/changepassword.jsp").forward(request, response);
+  }
+
+  /**
+   * This function fires when a user submits the change password form. It gets the
+   * username and password from the submitted form data, checks that they're valid, and
+   * either adds the user to the session so we know the user is logged in or shows an error
+   * to the user.
+   */
+  @Override
+  public void doPost(HttpServletRequest request, HttpServletResponse response)
+      throws IOException, ServletException {
+    String oldpassword = request.getParameter("oldpassword");
+    String username = (String) request.getSession().getAttribute("user");
+
+    if (userStore.isUserRegistered(username)) {
+      User user = userStore.getUser(username);
+      if (BCrypt.checkpw(oldpassword, user.getPassword())) {
+        if (request.getParameter("update") != null) {
+          String newPassword = request.getParameter("newpassword");
+          user.setPassword(newPassword);
+          userStore.addUser(user);
+          response.sendRedirect("/conversations");
+        }
+      } else {
+        request.setAttribute("error", "Invalid password.");
+        request.getRequestDispatcher("/WEB-INF/view/login.jsp").forward(request, response);
+      }
+    } else {
+      request.setAttribute("error", "No user logged in.");
+      request.getRequestDispatcher("/WEB-INF/view/login.jsp").forward(request, response);
+    }
+  }
+}

src/main/java/codeu/model/store/persistence/PersistentDataStore.java

@@ -188,6 +188,13 @@ public List<Profile> loadProfiles() throws PersistentDataStoreException {
 
   /** Write a User object to the Datastore service. */
   public void writeThrough(User user) {
+    // Delete user in entity if already present
+    Filter idFilter = new FilterPredicate("uuid", FilterOperator.EQUAL, user.getId().toString());
+    Query query = new Query("chat-users").setFilter(idFilter);
+    PreparedQuery results = datastore.prepare(query);
+    for (Entity entity : results.asIterable()) {
+      datastore.delete(entity.getKey());
+    }
     Entity userEntity = new Entity("chat-users");
     userEntity.setProperty("uuid", user.getId().toString());
     userEntity.setProperty("username", user.getName());

src/main/webapp/WEB-INF/view/changepassword.jsp

@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+<head>
+ <title>Register</title>
+ <link rel="stylesheet" href="/css/main.css">
+ <style>
+   label {
+	 display: inline-block;
+	 width: 100px;
+   }
+ </style>
+</head>
+<body>
+
+ <nav>
+   <a id="navTitle" href="/">CodeU Chat App</a>
+   <a href="/conversations">Conversations</a>
+   <% if(request.getSession().getAttribute("user") != null){ %>
+	 <a>Hello <%= request.getSession().getAttribute("user") %>!</a>
+	 <a href="/changepassword">Change Password</a>
+   <% } else{ %>
+	 <a href="/login">Login</a>
+	 <a href="/register">Register</a>
+   <% } %>
+   <a href="/about.jsp">About</a>
+ </nav>
+
+ <div id="container">
+   <h1>Change Password</h1>
+   <% if(request.getAttribute("error") != null){ %>
+	   <h2 style="color:red"><%= request.getAttribute("error") %></h2>
+   <% } %>
+   <form action="/changepassword" method="POST">
+	 <label for="oldpassword">Old Password: </label>
+	 <input type="password" name="oldpassword" id="oldpassword">
+	 <br/>
+	 <label for="newpassword">New Password: </labelpp>
+	 <input type="password" name="newpassword" id="newpassword">
+	 <br/><br/>
+	 <button type="submit">Submit</button>
+   </form>
+ </div>
+</body>
+</html>

src/main/webapp/WEB-INF/web.xml

@@ -36,6 +36,16 @@
     <url-pattern>/login</url-pattern>
   </servlet-mapping>
 
+  <servlet>
+    <servlet-name>ChangePasswordServlet</servlet-name>
+    <servlet-class>codeu.controller.ChangePasswordServlet</servlet-class>
+  </servlet>
+
+  <servlet-mapping>
+    <servlet-name>ChangePasswordServlet</servlet-name>
+    <url-pattern>/changepassword</url-pattern>
+  </servlet-mapping>
+
   <servlet>
     <servlet-name>ConversationServlet</servlet-name>
     <servlet-class>codeu.controller.ConversationServlet</servlet-class>