completed back-end app

LectureExamples/FirebaseDemo/.gitignore

@@ -7,3 +7,4 @@
 /build
 /captures
 .externalNativeBuild
+backend/src/main/webapp/WEB-INF/*.json

LectureExamples/FirebaseDemo/app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.andrejrasevic.firebasedemo">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

LectureExamples/FirebaseDemo/backend/build.gradle

+// If you would like more information on the gradle-appengine-plugin please refer to the github page
+// https://github.com/GoogleCloudPlatform/gradle-appengine-plugin
+
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.google.appengine:gradle-appengine-plugin:1.9.42'
+    }
+}
+
+repositories {
+    jcenter();
+}
+
+apply plugin: 'java'
+apply plugin: 'war'
+apply plugin: 'appengine'
+
+sourceCompatibility = JavaVersion.VERSION_1_7
+targetCompatibility = JavaVersion.VERSION_1_7
+
+dependencies {
+    appengineSdk 'com.google.appengine:appengine-java-sdk:1.9.42'
+    compile 'javax.servlet:servlet-api:2.5'
+    compile 'com.google.appengine:appengine-api-1.0-sdk:1.9.58'
+    compile 'com.google.firebase:firebase-server-sdk:3.0.3'
+    compile 'org.apache.httpcomponents:httpclient:4.5.3'
+}
+
+appengine {
+    downloadSdk = true
+    appcfg {
+        oauth2 = true
+    }
+}

LectureExamples/FirebaseDemo/backend/src/main/java/com/example/andrej/rasevic/myapplication/backend/MyServlet.java

+package com.example.andrej.rasevic.myapplication.backend;
+
+        import com.google.api.client.googleapis.auth.clientlogin.ClientLogin;
+        import com.google.firebase.FirebaseApp;
+        import com.google.firebase.FirebaseOptions;
+        import com.google.firebase.database.DataSnapshot;
+        import com.google.firebase.database.DatabaseError;
+        import com.google.firebase.database.DatabaseReference;
+        import com.google.firebase.database.FirebaseDatabase;
+        import com.google.firebase.database.ValueEventListener;
+
+        import java.io.FileInputStream;
+        import java.io.IOException;
+        import java.io.UnsupportedEncodingException;
+        import java.util.Iterator;
+        import java.util.Properties;
+        import java.util.logging.Logger;
+
+        import javax.mail.Message;
+        import javax.mail.MessagingException;
+        import javax.mail.Session;
+        import javax.mail.Transport;
+        import javax.mail.internet.InternetAddress;
+        import javax.mail.internet.MimeMessage;
+        import javax.servlet.http.*;
+        import javax.xml.ws.Response;
+
+public class MyServlet extends HttpServlet {
+    static Logger Log = Logger.getLogger("com.example.andrej.rasevic.myapplication.backend.MyServlet");
+
+    @Override
+    public void doGet(HttpServletRequest req, HttpServletResponse resp)
+            throws IOException {
+        Log.info("Sending the todo list email.");
+
+        String outString;
+        outString = "<p>Sending the todo list email.</p><p><strong>Note:</strong> ";
+        outString = outString.concat("the servlet must be deployed to App Engine in order to ");
+        outString = outString.concat("send the email. Running the server locally writes a message ");
+        outString = outString.concat("to the log file instead of sending an email message.</p>");
+
+        resp.getWriter().println(outString);
+
+        // Note: Ensure that the [PRIVATE_KEY_FILENAME].json has read
+        // permissions set.
+        FirebaseOptions options = new FirebaseOptions.Builder()
+                .setServiceAccount(getServletContext().getResourceAsStream("/WEB-INF/FirebaseDemo-a6320e903952.json"))
+                .setDatabaseUrl("https://fir-demo-d5acb.firebaseio.com/")
+                .build();
+
+        try {
+            FirebaseApp.getInstance();
+            Log.info("Got to here!");
+        }
+        catch (Exception error){
+            Log.info("doesn't exist...");
+        }
+
+        try {
+            FirebaseApp.initializeApp(options);
+            Log.info("now I got to here!!");
+        }
+        catch(Exception error){
+            Log.info("already exists...");
+        }
+
+        // As an admin, the app has access to read and write all data, regardless of Security Rules
+        DatabaseReference ref = FirebaseDatabase
+                .getInstance()
+                .getReference("todoItems");
+
+        // This fires when the servlet first runs, returning all the existing values
+        // only runs once, until the servlet starts up again.
+        ref.addListenerForSingleValueEvent(new ValueEventListener() {
+
+            @Override
+            public void onDataChange(DataSnapshot dataSnapshot) {
+                Object document = dataSnapshot.getValue();
+                Log.info("new value: "+ document);
+
+                String todoText = "Don't forget to...\n\n";
+
+                Iterator<DataSnapshot> children = dataSnapshot.getChildren().iterator();
+
+                while(children.hasNext()){
+                    DataSnapshot childSnapshot = (DataSnapshot) children.next();
+                    todoText = todoText + " * " + childSnapshot.getValue().toString() + "\n";
+                }
+
+                // Now send the email
+
+                // Note: When an application running in the development server calls the Mail
+                // service to send an email message, the message is printed to the log.
+                // The Java development server does not send the email message.
+
+                // You can test the email without waiting for the cron job to run by
+                // loading http://[FIREBASE_PROJECT_ID].appspot.com/send-email in your browser.
+
+                Properties props = new Properties();
+                Session session = Session.getDefaultInstance(props, null);
+                try {
+                    Message msg = new MimeMessage(session);
+                    //Make sure you substitute your project-id in the email From field
+                    msg.setFrom(new InternetAddress("reminder@fir-demo-d5acb.appspotmail.com",
+                            "FirebaseDemoApp Admin"));
+                    msg.addRecipient(Message.RecipientType.TO,
+                            new InternetAddress("andrej@rasevicengineering.com", "Recipient"));
+                    msg.addRecipient(Message.RecipientType.TO,
+                            new InternetAddress("arasevic@cs.umd.edu", "Recipient"));
+                    msg.setSubject("Things to do today");
+                    msg.addRecipient(Message.RecipientType.TO,
+                            new InternetAddress("aporter@cs.umd.edu", "Recipient"));
+                    msg.setText(todoText);
+                    Transport.send(msg);
+                } catch (MessagingException | UnsupportedEncodingException e) {
+                    Log.warning(e.getMessage());
+                }
+
+                // Note: in a production application you should replace the hard-coded email address
+                // above with code that populates msg.addRecipient with the app user's email address.
+            }
+
+            @Override
+            public void onCancelled(DatabaseError error){
+                System.out.println("Error: "+error);
+            }
+        });
+    }
+}
\ No newline at end of file

LectureExamples/FirebaseDemo/backend/src/main/webapp/WEB-INF/appengine-web.xml

+<?xml version="1.0" encoding="utf-8"?>
+<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
+    <application>fir-demo-d5acb</application>
+    <version>1</version>
+    <threadsafe>true</threadsafe>
+    <manual-scaling>
+        <instances>1</instances>
+    </manual-scaling>
+    <system-properties>
+        <property name="java.util.logging.config.file" value="WEB-INF/logging.properties" />
+    </system-properties>
+</appengine-web-app>
\ No newline at end of file

LectureExamples/FirebaseDemo/backend/src/main/webapp/WEB-INF/logging.properties

+# A default java.util.logging configuration.
+# (All App Engine logging is through java.util.logging by default).
+#
+# To use this configuration, copy it into your application's WEB-INF
+# folder and add the following to your appengine-web.xml:
+#
+# <system-properties>
+#   <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
+# </system-properties>
+#
+
+# Set the default logging level for all loggers to WARNING
+.level = WARNING

LectureExamples/FirebaseDemo/backend/src/main/webapp/WEB-INF/web.xml

+<?xml version="1.0" encoding="utf-8"?>
+<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee">
+    <servlet>
+        <servlet-name>MyServlet</servlet-name>
+        <servlet-class>com.example.andrej.rasevic.myapplication.backend.MyServlet</servlet-class>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>MyServlet</servlet-name>
+        <url-pattern>/send-email</url-pattern>
+    </servlet-mapping>
+    <welcome-file-list>
+        <welcome-file>index.html</welcome-file>
+    </welcome-file-list>
+</web-app>
\ No newline at end of file

LectureExamples/FirebaseDemo/backend/src/main/webapp/index.html

+<!DOCTYPE html>
+<html>
+<head>
+    <title>Hello, App Engine!</title>
+    <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
+    <link rel="stylesheet"
+          href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap-theme.min.css">
+</head>
+<body role="document" style="padding-top: 70px;">
+
+<div class="navbar navbar-inverse navbar-fixed-top" role="navigation">
+    <div class="container">
+        <div class="navbar-header">
+            <a class="navbar-brand" href="#">Hello, App Engine!</a>
+        </div>
+        <div class="navbar-collapse collapse">
+            <ul class="nav navbar-nav">
+                <li><a href="https://developers.google.com/appengine/docs/java/">Google App Engine
+                    documentation</a></li>
+                <li><a href="https://console.developers.google.com">Google Developers Console</a>
+                </li>
+            </ul>
+        </div>
+    </div>
+</div>
+
+<div class="container theme-showcase" role="main">
+    <div class="jumbotron">
+        <div class="row">
+            <div class="col-lg-12">
+                <h1>Hello, App Engine!</h1>
+                <p>Enter your name and press the button below to call <code>MyServlet</code>.</p>
+
+                <form action="/hello" method="POST">
+                    <div class="input-group">
+                        <input type="text" class="form-control input-lg" placeholder="Name"
+                               name="name"/>
+                        <span class="input-group-btn">
+                             <button class="btn btn-default btn-primary btn-group btn-lg"
+                                     type="submit" id="helloButton">Say "Hello";</button>
+                          </span>
+                    </div>
+                </form>
+                <br/>
+                <p>For more information about Google App Engine for Java, check out the <a
+                        href="https://developers.google.com/appengine/docs/java/">App Engine
+                    documentation</a>.</p>
+                <p>If you need step-by-step instructions for connecting your Android application to
+                    this backend module, see <a
+                            href="https://github.com/GoogleCloudPlatform/gradle-appengine-templates/tree/master/HelloWorld">"App
+                        Engine Java Servlet Module" template documentation</a>.</p>
+            </div>
+        </div>
+    </div>
+</div>
+
+</body>
+</html>

LectureExamples/FirebaseDemo/settings.gradle

-include ':app'
+include ':app', ':backend'