first commit

.gitignore

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+target/

README.md

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+OAuth2v1
+========
+
+A demo and helper class for providing Google OAuth2 v1 authentication in java.
+
+Assumptions
+
+- familiarity with OOP, java, maven, and jee
+- java application server listening on localhost:8080
+
+Prerequisites
+
+- Google API access credentials (Client ID, Client Secret). Set it up here https://code.google.com/apis/console/
+- Set up allowed Redirect URIs at Google API -> API Access. Input: http://localhost:8080/OAuth2v1/index.jsp
+- a positive outlook on life
+
+Usage
+
+1. Add Client ID, and Client Secret parameters to GoogleAuthHelper.java
+2. Compile the project ($ mvn clean install)
+3. Deploy war to application server
+4. Browse to: http://localhost:8080/OAuth2v1/
+5. Click "log in with google" on top of this page

pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>com.danter.auth.google</groupId>
+	<artifactId>OAuth2v1</artifactId>
+	<packaging>war</packaging>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>Demo Webapp for Google OAuth2</name>
+	<url>http://maven.apache.org</url>
+	<dependencies>
+		<dependency>
+			<groupId>com.google.http-client</groupId>
+			<artifactId>google-http-client</artifactId>
+			<version>1.13.1-beta</version>
+		</dependency>
+		<dependency>
+			<groupId>com.google.http-client</groupId>
+			<artifactId>google-http-client-jackson</artifactId>
+			<version>1.13.1-beta</version>
+		</dependency>
+		<dependency>
+			<groupId>javax</groupId>
+			<artifactId>javaee-web-api</artifactId>
+			<version>6.0</version>
+			<scope>provided</scope>
+		</dependency>
+		<dependency>
+			<groupId>com.google.apis</groupId>
+			<artifactId>google-api-services-oauth2</artifactId>
+			<version>v2-rev29-1.13.2-beta</version>
+		</dependency>
+	</dependencies>
+	<repositories>
+		<repository>
+			<id>google-api-services</id>
+			<url>http://google-api-client-libraries.appspot.com/mavenrepo</url>
+		</repository>
+	</repositories>
+	<build>
+		<finalName>OAuth2v1</finalName>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>2.3.2</version>
+				<configuration>
+					<source>1.6</source>
+					<target>1.6</target>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-war-plugin</artifactId>
+				<version>2.1.1</version>
+				<configuration>
+					<failOnMissingWebXml>false</failOnMissingWebXml>
+				</configuration>
+			</plugin>
+		</plugins>
+
+	</build>
+</project>

src/main/java/com/danter/google/auth/GoogleAuthHelper.java

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+package com.danter.google.auth;
+
+import com.google.api.client.auth.oauth2.Credential;
+import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
+import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeRequestUrl;
+import com.google.api.client.googleapis.auth.oauth2.GoogleTokenResponse;
+import com.google.api.client.http.GenericUrl;
+import com.google.api.client.http.HttpRequest;
+import com.google.api.client.http.HttpRequestFactory;
+import com.google.api.client.http.HttpTransport;
+import com.google.api.client.http.javanet.NetHttpTransport;
+import com.google.api.client.json.JsonFactory;
+import com.google.api.client.json.jackson.JacksonFactory;
+import java.io.IOException;
+import java.util.Arrays;
+
+/**
+ * A helper class for Google's OAuth2 authentication API.
+ * @version 20130224
+ * @author Matyas Danter
+ */
+public final class GoogleAuthHelper {
+
+	/**
+	 * Please provide a value for the CLIENT_ID constant before proceeding, set this up at https://code.google.com/apis/console/
+	 */
+	private static final String CLIENT_ID = "YOUR ID HERE";
+	/**
+	 * Please provide a value for the CLIENT_SECRET constant before proceeding, set this up at https://code.google.com/apis/console/
+	 */
+	private static final String CLIENT_SECRET = "SUPER SECRET SAUCE";
+
+	/**
+	 * Callback URI that google will redirect to after successful authentication
+	 */
+	private static final String CALLBACK_URI = "http://localhost:8080/OAuth2v1/index.jsp";
+
+	// start google authentication constants
+	private static final Iterable<String> SCOPE = Arrays.asList("https://www.googleapis.com/auth/userinfo.profile;https://www.googleapis.com/auth/userinfo.email".split(";"));
+	private static final String USER_INFO_URL = "https://www.googleapis.com/oauth2/v1/userinfo";
+	private static final JsonFactory JSON_FACTORY = new JacksonFactory();
+	private static final HttpTransport HTTP_TRANSPORT = new NetHttpTransport();
+	// end google authentication constants
+
+
+	private final GoogleAuthorizationCodeFlow flow;
+
+	/**
+	 * Constructor initializes the Google Authorization Code Flow with CLIENT ID, SECRET, and SCOPE 
+	 */
+	public GoogleAuthHelper() {
+		flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT,
+				JSON_FACTORY, CLIENT_ID, CLIENT_SECRET, SCOPE).build();
+	}
+
+	/**
+	 * Builds a login URL based on client ID, secret, callback URI, and scope 
+	 */
+	public String buildLoginUrl() {
+
+		final GoogleAuthorizationCodeRequestUrl url = flow.newAuthorizationUrl();
+
+		return url.setRedirectUri(CALLBACK_URI).setState("google").build();
+	}
+
+	/**
+	 * Expects an Authentication Code, and makes an authenticated request for the user's profile information
+	 * @return JSON formatted user profile information
+	 * @param authCode authentication code provided by google
+	 */
+	public String getUserInfoJson(final String authCode) throws IOException {
+
+		final GoogleTokenResponse response = flow.newTokenRequest(authCode).setRedirectUri(CALLBACK_URI).execute();
+		final Credential credential = flow.createAndStoreCredential(response, null);
+		final HttpRequestFactory requestFactory = HTTP_TRANSPORT.createRequestFactory(credential);
+		// Make an authenticated request
+		final GenericUrl url = new GenericUrl(USER_INFO_URL);
+		final HttpRequest request = requestFactory.buildGetRequest(url);
+		request.getHeaders().setContentType("application/json");
+		final String jsonIdentity = request.execute().parseAsString();
+
+		return jsonIdentity;
+
+	}
+
+
+
+}

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

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+<!DOCTYPE web-app PUBLIC
+ "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
+ "http://java.sun.com/dtd/web-app_2_3.dtd" >
+
+<web-app>
+  <display-name>Demo Webapp for Google OAuth2</display-name>
+</web-app>

src/main/webapp/index.jsp

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+<%@page import="com.danter.google.auth.GoogleAuthHelper"%>
+<%@page contentType="text/html" pageEncoding="UTF-8"%>
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
+    "http://www.w3.org/TR/html4/loose.dtd">
+
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+<title>Google OAuth 2.0 v1 Demo</title>
+<style>
+body {
+	font-family: Sans-Serif;
+	margin: 1em;
+}
+
+.oauthDemo a {
+	display: block;
+	border-style: solid;
+	border-color: #bbb #888 #666 #aaa;
+	border-width: 1px 2px 2px 1px;
+	background: #ccc;
+	color: #333;
+	line-height: 2;
+	text-align: center;
+	text-decoration: none;
+	font-weight: 900;
+	width: 13em;
+}
+
+.oauthDemo pre {
+	background: #ccc;
+}
+
+.oauthDemo a:active {
+	border-color: #666 #aaa #bbb #888;
+	border-width: 2px 1px 1px 2px;
+	color: #000;
+}
+
+.readme {
+	padding: .5em;
+	background-color: #F9AD81;
+	color: #333;
+}
+</style>
+</head>
+<body>
+	<div class="oauthDemo">
+		<%
+			/*
+			 * The GoogleAuthHelper handles all the heavy lifting, and contains all "secrets"
+			 * required for constructing a google login url.
+			 */
+			final GoogleAuthHelper helper = new GoogleAuthHelper();
+
+			if (request.getParameter("code") == null
+					|| request.getParameter("state") == null) {
+
+				/*
+				 * initial visit to the page
+				 */
+				out.println("<a href='" + helper.buildLoginUrl()
+						+ "'>log in with google</a>");
+
+			} else if (request.getParameter("code") != null
+					&& request.getParameter("state").equals("google")) {
+
+				out.println("<pre>");
+				/*
+				 * Executes after google redirects to the callback url.
+				 * Please note that the state request parameter is for convenience to differentiate
+				 * between authentication methods (ex. facebook oauth, google oauth, twitter, in-house).
+				 * 
+				 * GoogleAuthHelper()#getUserInfoJson(String) method returns a String containing
+				 * the json representation of the authenticated user's information. 
+				 * At this point you should parse and persist the info.
+				 */
+
+				out.println(helper.getUserInfoJson(request.getParameter("code")));
+
+				out.println("</pre>");
+			}
+		%>
+	</div>
+	<br />
+	<div class="readme">
+		<h1>Read Me First</h1>
+
+		<h3>Assumptions</h3>
+
+		<ul>
+			<li>familiarity with OOP, java, maven, and jee</li>
+			<li>java application server listening on localhost:8080</li>
+		</ul>
+
+		<h3>Prerequisites</h3>
+
+		<ul>
+			<li>Google API access credentials (Client ID, Client Secret).
+				Set it up here <a href='https://code.google.com/apis/console/'>https://code.google.com/apis/console/</a>
+			</li>
+			<li>Set up allowed Redirect URIs at Google API &rarr; API
+				Access. Input: http://localhost:8080/OAuth2v1/index.jsp</li>
+			<li>a positive outlook on life</li>
+		</ul>
+
+		<h3>Usage</h3>
+
+		<ol>
+			<li>Add Client ID, and Client Secret parameters to <b>GoogleAuthHelper.java</b></li>
+			<li>Compile the project (<b>$ mvn clean install</b>)</li>
+			<li>Deploy war to application server</li>
+			<li>Browse to: <a href="http://localhost:8080/OAuth2v1/">http://localhost:8080/OAuth2v1/</a></li>
+			<li>Click <b>&quot;log in with google&quot;</b> on top of this page</li>
+		</ol>
+
+	</div>
+</body>
+</html>

src/main/webapp/readme.txt

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+Assumptions
+
+- familiarity with OOP, java, maven, and jee
+- java application server listening on localhost:8080
+
+Prerequisites
+
+- Google API access credentials (Client ID, Client Secret). Set it up here https://code.google.com/apis/console/
+- Set up allowed Redirect URIs at Google API -> API Access. Input: http://localhost:8080/OAuth2v1/index.jsp
+- a positive outlook on life
+
+Usage
+
+1. Add Client ID, and Client Secret parameters to GoogleAuthHelper.java
+2. Compile the project ($ mvn clean install)
+3. Deploy war to application server
+4. Browse to: http://localhost:8080/OAuth2v1/
+5. Click "log in with google" on top of this page