diff --git a/core-java/src/test/java/org/baeldung/java/collections/CollectionsConcatenateUnitTest.java b/core-java/src/test/java/org/baeldung/java/collections/CollectionsConcatenateUnitTest.java
new file mode 100644
index 0000000000..3ee08767bd
--- /dev/null
+++ b/core-java/src/test/java/org/baeldung/java/collections/CollectionsConcatenateUnitTest.java
@@ -0,0 +1,116 @@
+package org.baeldung.java.collections;
+
+import static java.util.Arrays.asList;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+
+public class CollectionsConcatenateUnitTest {
+
+    @Test
+    public void givenUsingJava8_whenConcatenatingUsingConcat_thenCorrect() {
+        Collection<String> collectionA = asList("S", "T");
+        Collection<String> collectionB = asList("U", "V");
+        Collection<String> collectionC = asList("W", "X");
+
+        Stream<String> combinedStream = Stream.concat(Stream.concat(collectionA.stream(), collectionB.stream()), collectionC.stream());
+        Collection<String> collectionCombined = combinedStream.collect(Collectors.toList());
+
+        Assert.assertEquals(asList("S", "T", "U", "V", "W", "X"), collectionCombined);
+    }
+
+    @Test
+    public void givenUsingJava8_whenConcatenatingUsingflatMap_thenCorrect() {
+        Collection<String> collectionA = asList("S", "T");
+        Collection<String> collectionB = asList("U", "V");
+
+        Stream<String> combinedStream = Stream.of(collectionA, collectionB).flatMap(Collection::stream);
+        Collection<String> collectionCombined = combinedStream.collect(Collectors.toList());
+
+        Assert.assertEquals(asList("S", "T", "U", "V"), collectionCombined);
+    }
+
+    @Test
+    public void givenUsingGuava_whenConcatenatingUsingIterables_thenCorrect() {
+        Collection<String> collectionA = asList("S", "T");
+        Collection<String> collectionB = asList("U", "V");
+
+        Iterable<String> combinedIterables = Iterables.unmodifiableIterable(Iterables.concat(collectionA, collectionB));
+        Collection<String> collectionCombined = Lists.newArrayList(combinedIterables);
+
+        Assert.assertEquals(asList("S", "T", "U", "V"), collectionCombined);
+    }
+
+    @Test
+    public void givenUsingJava7_whenConcatenatingUsingIterables_thenCorrect() {
+        Collection<String> collectionA = asList("S", "T");
+        Collection<String> collectionB = asList("U", "V");
+
+        Iterable<String> combinedIterables = concat(collectionA, collectionB);
+        Collection<String> collectionCombined = makeListFromIterable(combinedIterables);
+        Assert.assertEquals(Arrays.asList("S", "T", "U", "V"), collectionCombined);
+    }
+
+    public static <E> Iterable<E> concat(Iterable<? extends E> list1, Iterable<? extends E> list2) {
+        return new Iterable<E>() {
+            public Iterator<E> iterator() {
+                return new Iterator<E>() {
+                    protected Iterator<? extends E> listIterator = list1.iterator();
+                    protected Boolean checkedHasNext;
+                    protected E nextValue;
+                    private boolean startTheSecond;
+
+                    public void theNext() {
+                        if (listIterator.hasNext()) {
+                            checkedHasNext = true;
+                            nextValue = listIterator.next();
+                        } else if (startTheSecond)
+                            checkedHasNext = false;
+                        else {
+                            startTheSecond = true;
+                            listIterator = list2.iterator();
+                            theNext();
+                        }
+                    }
+
+                    public boolean hasNext() {
+                        if (checkedHasNext == null)
+                            theNext();
+                        return checkedHasNext;
+                    }
+
+                    public E next() {
+                        if (!hasNext())
+                            throw new NoSuchElementException();
+                        checkedHasNext = null;
+                        return nextValue;
+                    }
+
+                    public void remove() {
+                        listIterator.remove();
+                    }
+                };
+            }
+        };
+    }
+
+    public static <E> List<E> makeListFromIterable(Iterable<E> iter) {
+        List<E> list = new ArrayList<E>();
+        for (E item : iter) {
+            list.add(item);
+        }
+        return list;
+    }
+}
diff --git a/spring-security-client/README.MD b/spring-security-client/README.MD
index 5ac974203b..0b0af7ffe1 100644
--- a/spring-security-client/README.MD
+++ b/spring-security-client/README.MD
@@ -1,2 +1,11 @@
-###The Course
+=========
+## Spring Security Authentication/Authorization Example Project
+
+##The Course
 The "REST With Spring" Classes: http://github.learnspringsecurity.com
+
+### Relevant Articles: 
+- [Spring Security Manual Authentication](http://www.baeldung.com/spring-security-authentication)
+
+### Build the Project
+mvn clean install
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfig.java b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfig.java
index 9ade60e54c..259433f6ae 100644
--- a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfig.java
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfig.java
@@ -8,9 +8,11 @@ import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+import org.springframework.context.annotation.Profile;
 
 @Configuration
 @EnableWebMvc
+@Profile("!manual")
 public class MvcConfig extends WebMvcConfigurerAdapter {
 
     public MvcConfig() {
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfigManual.java b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfigManual.java
new file mode 100644
index 0000000000..d80527c30a
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/MvcConfigManual.java
@@ -0,0 +1,22 @@
+package org.baeldung.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+@Configuration
+@EnableWebMvc
+@Profile("manual")
+public class MvcConfigManual extends WebMvcConfigurerAdapter {
+
+    @Override
+    public void addViewControllers(ViewControllerRegistry registry) {
+        registry.addViewController("/home").setViewName("home");
+        registry.addViewController("/").setViewName("home");
+        registry.addViewController("/hello").setViewName("hello");
+        registry.addViewController("/login").setViewName("login");
+    }
+
+}
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/RegistrationController.java b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/RegistrationController.java
new file mode 100644
index 0000000000..025001ac44
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/RegistrationController.java
@@ -0,0 +1,92 @@
+package org.baeldung.config;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.BadCredentialsException;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.web.authentication.WebAuthenticationDetails;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.context.annotation.Profile;
+
+/**
+ * Manually authenticate a user using Spring Security / Spring Web MVC' (upon successful account registration)
+ * (http://stackoverflow.com/questions/4664893/how-to-manually-set-an-authenticated-user-in-spring-security-springmvc)
+ * 
+ * @author jim clayson
+ */
+@Controller
+@Profile("manual")
+public class RegistrationController {
+    private static final Logger logger = LoggerFactory.getLogger(RegistrationController.class);
+
+    @Autowired
+    AuthenticationManager authenticationManager;
+
+    /**
+     * For demo purposes this need only be a GET request method
+     * 
+     * @param request
+     * @param response
+     * @return The view. Page confirming either successful registration (and/or
+     *         successful authentication) or failed registration.
+     */
+    @RequestMapping(value = "/register", method = RequestMethod.GET)
+    public String registerAndAuthenticate(HttpServletRequest request, HttpServletResponse response) {
+        logger.debug("registerAndAuthenticate: attempt to register, application should manually authenticate.");
+
+        // Mocked values. Potentially could come from an HTML registration form,
+        // in which case this mapping would match on an HTTP POST, rather than a GET
+        String username = "user";
+        String password = "password";
+
+        String view = "registrationSuccess";
+
+        if (requestQualifiesForManualAuthentication()) {
+            try {
+                authenticate(username, password, request, response);
+                logger.debug("registerAndAuthenticate: authentication completed.");
+            } catch (BadCredentialsException bce) {
+                logger.debug("Authentication failure: bad credentials");
+                bce.printStackTrace();
+                view = "systemError"; // assume a low-level error, since the registration
+                // form would have been successfully validated
+            }
+        }
+
+        return view;
+    }
+
+    private boolean requestQualifiesForManualAuthentication() {
+        // Some processing to determine that the user requires a Spring Security-recognized,
+        // application-directed login e.g. successful account registration.
+        return true;
+    }
+
+    private void authenticate(String username, String password, HttpServletRequest request, HttpServletResponse response) throws BadCredentialsException {
+        logger.debug("attempting to authenticated, manually ... ");
+
+        // create and populate the token
+        AbstractAuthenticationToken authToken = new UsernamePasswordAuthenticationToken(username, password);
+        authToken.setDetails(new WebAuthenticationDetails(request));
+
+        // This call returns an authentication object, which holds principle and user credentials
+        Authentication authentication = this.authenticationManager.authenticate(authToken);
+
+        // The security context holds the authentication object, and is stored
+        // in thread local scope.
+        SecurityContextHolder.getContext().setAuthentication(authentication);
+
+        logger.debug("User should now be authenticated.");
+    }
+
+}
\ No newline at end of file
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/SecurityConfig.java b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/SecurityConfig.java
index bd6c56d38a..153cc67661 100644
--- a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/SecurityConfig.java
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/SecurityConfig.java
@@ -6,9 +6,11 @@ import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.builders.WebSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.context.annotation.Profile;
 
 @Configuration
 @EnableWebSecurity
+@Profile("!manual")
 public class SecurityConfig extends WebSecurityConfigurerAdapter {
 
     @Override
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/WebSecurityConfigManual.java b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/WebSecurityConfigManual.java
new file mode 100644
index 0000000000..180a53deba
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/java/org/baeldung/config/WebSecurityConfigManual.java
@@ -0,0 +1,35 @@
+package org.baeldung.config;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+
+@Configuration
+@EnableWebSecurity
+@Profile("manual")
+public class WebSecurityConfigManual extends WebSecurityConfigurerAdapter {
+
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+     // @formatter:off
+        http
+            .authorizeRequests()
+                .antMatchers("/", "/home", "/register").permitAll()
+                .anyRequest().authenticated()
+                .and()
+            .formLogin()
+                .loginPage("/login").permitAll()
+                .and()
+            .logout().permitAll();
+     // @formatter:on
+    }
+
+    @Autowired
+    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
+        auth.inMemoryAuthentication().withUser("user").password("password").roles("USER");
+    }
+}
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/hello.html b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/hello.html
new file mode 100644
index 0000000000..b37731b0ed
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/hello.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
+      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
+    <head>
+        <title>Hello World!</title>
+    </head>
+    <body>
+        <h1 th:inline="text">Hello [[${#httpServletRequest.remoteUser}]]!</h1>
+        <form th:action="@{/logout}" method="post">
+            <input type="submit" value="Sign Out"/>
+        </form>
+        <p>Click <a th:href="@{/home}">here</a> to go to the home page.</p>
+        
+    </body>
+</html>
\ No newline at end of file
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/home.html b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/home.html
new file mode 100644
index 0000000000..6dbdf491c6
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/home.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html 
+	xmlns="http://www.w3.org/1999/xhtml" 
+	xmlns:th="http://www.thymeleaf.org" 
+	xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity4">
+    <head>
+        <title>Spring Security Example</title>
+    </head>
+    <body>
+        <h1>Welcome!</h1>
+        
+        <p>Click <a th:href="@{/hello}">here</a> to see a greeting.</p>
+        <p sec:authorize="isAnonymous()">Click <a th:href="@{/register}">here</a> to send a dummy registration request, where the application logs you in.</p>
+    </body>
+</html>
\ No newline at end of file
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/login.html b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/login.html
new file mode 100644
index 0000000000..3f28efac69
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/login.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
+      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
+    <head>
+        <title>Spring Security Example </title>
+    </head>
+    <body>
+        <div th:if="${param.error}">
+            Invalid username and password.
+        </div>
+        <div th:if="${param.logout}">
+            You have been logged out.
+        </div>
+        <form th:action="@{/login}" method="post">
+            <div><label> User Name : <input type="text" name="username"/> </label></div>
+            <div><label> Password: <input type="password" name="password"/> </label></div>
+            <div><input type="submit" value="Sign In"/></div>
+        </form>
+        <p>Click <a th:href="@{/home}">here</a> to go to the home page.</p>
+    </body>
+</html>
\ No newline at end of file
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationError.html b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationError.html
new file mode 100644
index 0000000000..756cc2390d
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationError.html
@@ -0,0 +1 @@
+Registration could not be completed at this time. Please try again later or contact support!
\ No newline at end of file
diff --git a/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationSuccess.html b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationSuccess.html
new file mode 100644
index 0000000000..b1c4336f2f
--- /dev/null
+++ b/spring-security-client/spring-security-thymeleaf-authentication/src/main/resources/templates/registrationSuccess.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"
+      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
+    <head>
+        <title>Registration Success!</title>
+    </head>
+    <body>
+        <h2 th:inline="text">Registration succeeded. You have been logged in by the system. Welcome [[${#httpServletRequest.remoteUser}]]!</h2>
+        <form th:action="@{/logout}" method="post">
+            <input type="submit" value="Sign Out"/>
+        </form>
+        <p>Click <a th:href="@{/home}">here</a> to go to the home page.</p>
+        
+    </body>
+</html>
\ No newline at end of file