From 9b4ee4aae3281999addc3426455288707962c3dc Mon Sep 17 00:00:00 2001
From: sampadawagde <sampada.wagde@gmail.com>
Date: Fri, 19 Jun 2020 23:06:12 +0530
Subject: [PATCH] BAEL-4019: Exploring Java Security frameworks

---
 java-security/.gitignore                      |  4 +
 java-security/README.md                       |  8 ++
 java-security/apache-shiro/.gitignore         |  4 +
 java-security/apache-shiro/pom.xml            | 40 ++++++++
 .../java/com/baeldung/shiro/CustomRealm.java  | 92 ++++++++++++++++++
 .../com/baeldung/shiro/ShiroApplication.java  | 32 +++++++
 .../shiro/controllers/ShiroController.java    | 95 +++++++++++++++++++
 .../shiro/models/UserCredentials.java         | 28 ++++++
 .../src/main/resources/application.yml        | 16 ++++
 .../src/main/resources/templates/home.ftl     | 19 ++++
 .../src/main/resources/templates/index.ftl    | 10 ++
 .../src/main/resources/templates/login.ftl    | 25 +++++
 .../com/baeldung/shiro/SpringContextTest.java | 18 ++++
 java-security/pom.xml                         | 22 +++++
 java-security/spring-security/.gitignore      |  4 +
 java-security/spring-security/pom.xml         | 31 ++++++
 .../baeldung/springsecurity/Application.java  | 12 +++
 .../springsecurity/config/SecurityConfig.java | 45 +++++++++
 .../springsecurity/web/SpringController.java  | 79 +++++++++++++++
 .../src/main/resources/application.yml        | 12 +++
 .../src/main/resources/templates/home.ftl     | 20 ++++
 .../src/main/resources/templates/index.ftl    | 10 ++
 .../src/main/resources/templates/login.ftl    | 26 +++++
 .../springsecurity/SpringContextTest.java     | 17 ++++
 24 files changed, 669 insertions(+)
 create mode 100644 java-security/.gitignore
 create mode 100644 java-security/README.md
 create mode 100644 java-security/apache-shiro/.gitignore
 create mode 100644 java-security/apache-shiro/pom.xml
 create mode 100644 java-security/apache-shiro/src/main/java/com/baeldung/shiro/CustomRealm.java
 create mode 100644 java-security/apache-shiro/src/main/java/com/baeldung/shiro/ShiroApplication.java
 create mode 100644 java-security/apache-shiro/src/main/java/com/baeldung/shiro/controllers/ShiroController.java
 create mode 100644 java-security/apache-shiro/src/main/java/com/baeldung/shiro/models/UserCredentials.java
 create mode 100644 java-security/apache-shiro/src/main/resources/application.yml
 create mode 100644 java-security/apache-shiro/src/main/resources/templates/home.ftl
 create mode 100644 java-security/apache-shiro/src/main/resources/templates/index.ftl
 create mode 100644 java-security/apache-shiro/src/main/resources/templates/login.ftl
 create mode 100644 java-security/apache-shiro/src/test/java/com/baeldung/shiro/SpringContextTest.java
 create mode 100644 java-security/pom.xml
 create mode 100644 java-security/spring-security/.gitignore
 create mode 100644 java-security/spring-security/pom.xml
 create mode 100644 java-security/spring-security/src/main/java/com/baeldung/springsecurity/Application.java
 create mode 100644 java-security/spring-security/src/main/java/com/baeldung/springsecurity/config/SecurityConfig.java
 create mode 100644 java-security/spring-security/src/main/java/com/baeldung/springsecurity/web/SpringController.java
 create mode 100644 java-security/spring-security/src/main/resources/application.yml
 create mode 100644 java-security/spring-security/src/main/resources/templates/home.ftl
 create mode 100644 java-security/spring-security/src/main/resources/templates/index.ftl
 create mode 100644 java-security/spring-security/src/main/resources/templates/login.ftl
 create mode 100644 java-security/spring-security/src/test/java/com/baeldung/springsecurity/SpringContextTest.java

diff --git a/java-security/.gitignore b/java-security/.gitignore
new file mode 100644
index 0000000000..020cda4898
--- /dev/null
+++ b/java-security/.gitignore
@@ -0,0 +1,4 @@
+
+/.idea/
+/target/
+/apache-shiro.iml
\ No newline at end of file
diff --git a/java-security/README.md b/java-security/README.md
new file mode 100644
index 0000000000..bdf020ac4c
--- /dev/null
+++ b/java-security/README.md
@@ -0,0 +1,8 @@
+## Java Security
+
+This module contains articles about Java security frameworks
+
+### Relevant articles:
+
+
+
diff --git a/java-security/apache-shiro/.gitignore b/java-security/apache-shiro/.gitignore
new file mode 100644
index 0000000000..020cda4898
--- /dev/null
+++ b/java-security/apache-shiro/.gitignore
@@ -0,0 +1,4 @@
+
+/.idea/
+/target/
+/apache-shiro.iml
\ No newline at end of file
diff --git a/java-security/apache-shiro/pom.xml b/java-security/apache-shiro/pom.xml
new file mode 100644
index 0000000000..ad8bf67afc
--- /dev/null
+++ b/java-security/apache-shiro/pom.xml
@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-shiro</artifactId>
+    <name>apache-shiro</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>java-security</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-freemarker</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.shiro</groupId>
+            <artifactId>shiro-spring-boot-web-starter</artifactId>
+            <version>${apache-shiro-core-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.shiro</groupId>
+            <artifactId>shiro-core</artifactId>
+            <version>${apache-shiro-core-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>jcl-over-slf4j</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <apache-shiro-core-version>1.5.3</apache-shiro-core-version>
+    </properties>
+
+</project>
diff --git a/java-security/apache-shiro/src/main/java/com/baeldung/shiro/CustomRealm.java b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/CustomRealm.java
new file mode 100644
index 0000000000..d911f37c20
--- /dev/null
+++ b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/CustomRealm.java
@@ -0,0 +1,92 @@
+package com.baeldung.shiro;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.shiro.authc.AuthenticationException;
+import org.apache.shiro.authc.AuthenticationInfo;
+import org.apache.shiro.authc.AuthenticationToken;
+import org.apache.shiro.authc.SimpleAuthenticationInfo;
+import org.apache.shiro.authc.UnknownAccountException;
+import org.apache.shiro.authc.UsernamePasswordToken;
+import org.apache.shiro.authz.AuthorizationInfo;
+import org.apache.shiro.authz.SimpleAuthorizationInfo;
+import org.apache.shiro.realm.jdbc.JdbcRealm;
+import org.apache.shiro.subject.PrincipalCollection;
+
+public class CustomRealm extends JdbcRealm {
+
+    private Map<String, String> credentials = new HashMap<>();
+    private Map<String, Set<String>> roles = new HashMap<>();
+    private Map<String, Set<String>> permissions = new HashMap<>();
+
+    {
+        credentials.put("Tom", "password");
+        credentials.put("Jerry", "password");
+
+        roles.put("Jerry", new HashSet<>(Arrays.asList("ADMIN")));
+        roles.put("Tom", new HashSet<>(Arrays.asList("USER")));
+
+        permissions.put("ADMIN", new HashSet<>(Arrays.asList("READ", "WRITE")));
+        permissions.put("USER", new HashSet<>(Arrays.asList("READ")));
+    }
+
+    @Override
+    protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
+
+        UsernamePasswordToken userToken = (UsernamePasswordToken) token;
+
+        if (userToken.getUsername() == null || userToken.getUsername()
+            .isEmpty() || !credentials.containsKey(userToken.getUsername())) {
+            throw new UnknownAccountException("User doesn't exist");
+        }
+
+        return new SimpleAuthenticationInfo(userToken.getUsername(), credentials.get(userToken.getUsername()), getName());
+    }
+
+    @Override
+    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
+        Set<String> roles = new HashSet<>();
+        Set<String> permissions = new HashSet<>();
+
+        for (Object user : principals) {
+            try {
+                roles.addAll(getRoleNamesForUser(null, (String) user));
+                permissions.addAll(getPermissions(null, null, roles));
+            } catch (SQLException e) {
+                e.printStackTrace();
+            }
+        }
+        SimpleAuthorizationInfo authInfo = new SimpleAuthorizationInfo(roles);
+        authInfo.setStringPermissions(permissions);
+        return authInfo;
+    }
+
+    @Override
+    protected Set<String> getRoleNamesForUser(Connection conn, String username) throws SQLException {
+        if (!roles.containsKey(username)) {
+            throw new SQLException("User doesn't exist");
+        }
+        return roles.get(username);
+    }
+
+    @Override
+    protected Set<String> getPermissions(Connection conn, String username, Collection<String> roles) throws SQLException {
+        Set<String> userPermissions = new HashSet<>();
+
+        for (String role : roles) {
+            if (!permissions.containsKey(role)) {
+                throw new SQLException("Role doesn't exist");
+            }
+            userPermissions.addAll(permissions.get(role));
+        }
+        return userPermissions;
+    }
+
+}
diff --git a/java-security/apache-shiro/src/main/java/com/baeldung/shiro/ShiroApplication.java b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/ShiroApplication.java
new file mode 100644
index 0000000000..16c50ff1c5
--- /dev/null
+++ b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/ShiroApplication.java
@@ -0,0 +1,32 @@
+package com.baeldung.shiro;
+
+import org.apache.shiro.realm.Realm;
+import org.apache.shiro.spring.web.config.DefaultShiroFilterChainDefinition;
+import org.apache.shiro.spring.web.config.ShiroFilterChainDefinition;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class ShiroApplication {
+
+    public static void main(String... args) {
+        SpringApplication.run(ShiroApplication.class, args);
+    }
+
+    @Bean
+    public Realm realm() {
+        return new CustomRealm();
+    }
+
+    @Bean
+    public ShiroFilterChainDefinition shiroFilterChainDefinition() {
+        DefaultShiroFilterChainDefinition filter = new DefaultShiroFilterChainDefinition();
+
+        filter.addPathDefinition("/home", "authc");
+        filter.addPathDefinition("/**", "anon");
+
+        return filter;
+    }
+
+}
diff --git a/java-security/apache-shiro/src/main/java/com/baeldung/shiro/controllers/ShiroController.java b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/controllers/ShiroController.java
new file mode 100644
index 0000000000..8e9403d3d3
--- /dev/null
+++ b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/controllers/ShiroController.java
@@ -0,0 +1,95 @@
+package com.baeldung.shiro.controllers;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authc.AuthenticationException;
+import org.apache.shiro.authc.UsernamePasswordToken;
+import org.apache.shiro.subject.Subject;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
+
+import com.baeldung.shiro.models.UserCredentials;
+
+@Controller
+public class ShiroController {
+
+    @GetMapping("/")
+    public String index() {
+        return "index";
+    }
+
+    @GetMapping("/login")
+    public String showLoginPage() {
+        return "login";
+    }
+
+    @PostMapping("/login")
+    public String doLogin(HttpServletRequest req, UserCredentials credentials, RedirectAttributes attr) {
+
+        Subject subject = SecurityUtils.getSubject();
+
+        if (!subject.isAuthenticated()) {
+            UsernamePasswordToken token = new UsernamePasswordToken(credentials.getUsername(), credentials.getPassword());
+            try {
+                subject.login(token);
+            } catch (AuthenticationException ae) {
+                ae.printStackTrace();
+                attr.addFlashAttribute("error", "Invalid Credentials");
+                return "redirect:/login";
+            }
+        }
+        return "redirect:/home";
+    }
+
+    @GetMapping("/home")
+    public String getMeHome(Model model) {
+
+        addUserAttributes(model);
+
+        return "home";
+    }
+
+    @GetMapping("/admin")
+    public String adminOnly(Model model) {
+        addUserAttributes(model);
+
+        Subject currentUser = SecurityUtils.getSubject();
+        if (currentUser.hasRole("ADMIN")) {
+            model.addAttribute("adminContent", "only admin can view this");
+        }
+        return "home";
+    }
+
+    @PostMapping("/logout")
+    public String logout() {
+        Subject subject = SecurityUtils.getSubject();
+        subject.logout();
+        return "redirect:/";
+    }
+
+    private void addUserAttributes(Model model) {
+        Subject currentUser = SecurityUtils.getSubject();
+        String permission = "";
+
+        if (currentUser.hasRole("ADMIN")) {
+            model.addAttribute("role", "ADMIN");
+        } else if (currentUser.hasRole("USER")) {
+            model.addAttribute("role", "USER");
+        }
+
+        if (currentUser.isPermitted("READ")) {
+            permission = permission + " READ";
+        }
+
+        if (currentUser.isPermitted("WRITE")) {
+            permission = permission + " WRITE";
+        }
+        model.addAttribute("username", currentUser.getPrincipal());
+        model.addAttribute("permission", permission);
+    }
+
+}
diff --git a/java-security/apache-shiro/src/main/java/com/baeldung/shiro/models/UserCredentials.java b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/models/UserCredentials.java
new file mode 100644
index 0000000000..5dbafa30ec
--- /dev/null
+++ b/java-security/apache-shiro/src/main/java/com/baeldung/shiro/models/UserCredentials.java
@@ -0,0 +1,28 @@
+package com.baeldung.shiro.models;
+
+public class UserCredentials {
+
+    private String username;
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    @Override
+    public String toString() {
+        return "username = " + getUsername();
+    }
+}
diff --git a/java-security/apache-shiro/src/main/resources/application.yml b/java-security/apache-shiro/src/main/resources/application.yml
new file mode 100644
index 0000000000..509f655919
--- /dev/null
+++ b/java-security/apache-shiro/src/main/resources/application.yml
@@ -0,0 +1,16 @@
+server:
+  port: 8081
+
+logging:
+  level:
+    root: WARN
+    org.springframework.web: INFO
+
+shiro:
+  loginUrl: /login
+  successUrl: /home
+  unauthorizedUrl: /login
+
+spring:
+  freemarker:
+    suffix: .ftl
\ No newline at end of file
diff --git a/java-security/apache-shiro/src/main/resources/templates/home.ftl b/java-security/apache-shiro/src/main/resources/templates/home.ftl
new file mode 100644
index 0000000000..37eb3d1812
--- /dev/null
+++ b/java-security/apache-shiro/src/main/resources/templates/home.ftl
@@ -0,0 +1,19 @@
+<html>
+<head>
+    <title>Home Page</title>
+</head>
+<body style="margin-left: 30px;">
+<h1>Welcome ${username}!</h1>
+<p><strong>Role</strong>: ${role}</p>
+<p><strong>Permissions</strong></p>
+<p>${permission}</p>
+<a href="/admin">Admin only</a>
+<#if adminContent??>
+  ${adminContent}
+</#if>
+<br>
+<form role="form" action="/logout" method="POST">
+   <input type="Submit" value="Logout" />
+</form>
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/apache-shiro/src/main/resources/templates/index.ftl b/java-security/apache-shiro/src/main/resources/templates/index.ftl
new file mode 100644
index 0000000000..0210d656fc
--- /dev/null
+++ b/java-security/apache-shiro/src/main/resources/templates/index.ftl
@@ -0,0 +1,10 @@
+<html>
+<head>
+    <title>Index</title>
+</head>
+<body>
+    <h1>Welcome Guest!</h1>
+    <br>
+    <a href="/login">Login</a>
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/apache-shiro/src/main/resources/templates/login.ftl b/java-security/apache-shiro/src/main/resources/templates/login.ftl
new file mode 100644
index 0000000000..7340f47204
--- /dev/null
+++ b/java-security/apache-shiro/src/main/resources/templates/login.ftl
@@ -0,0 +1,25 @@
+<html>
+<head>
+    <title>Login</title>
+</head>
+<body style="margin-left: 30px;">
+<h3>Login</h3>
+<br>
+<form action="/login" method="post">
+    <#if (error?length > 0)??>
+        <p style="color:darkred;">${error}</p>
+    <#else>
+    </#if>
+
+    <label for="username">Username</label>
+    <br>
+    <input type="text" name="username">
+    <br><br>
+    <label for="password">Password</label>
+    <br>
+    <input type="password" name="password">
+    <br><br>
+    <input type="submit" value="Submit">
+</form>
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/apache-shiro/src/test/java/com/baeldung/shiro/SpringContextTest.java b/java-security/apache-shiro/src/test/java/com/baeldung/shiro/SpringContextTest.java
new file mode 100644
index 0000000000..0b5e690403
--- /dev/null
+++ b/java-security/apache-shiro/src/test/java/com/baeldung/shiro/SpringContextTest.java
@@ -0,0 +1,18 @@
+package com.baeldung.shiro;
+
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@SpringBootTest(classes = { ShiroApplication.class })
+public class SpringContextTest {
+
+    @Test
+    public void whenSpringContextIsBootstrapped_thenNoExceptions() {
+
+    }
+
+}
\ No newline at end of file
diff --git a/java-security/pom.xml b/java-security/pom.xml
new file mode 100644
index 0000000000..f6e0df3990
--- /dev/null
+++ b/java-security/pom.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>java-security</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <name>java-security</name>
+    <packaging>pom</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-2</relativePath>
+    </parent>
+
+    <modules>
+        <module>apache-shiro</module>
+        <module>spring-security</module>
+    </modules>
+
+</project>
diff --git a/java-security/spring-security/.gitignore b/java-security/spring-security/.gitignore
new file mode 100644
index 0000000000..020cda4898
--- /dev/null
+++ b/java-security/spring-security/.gitignore
@@ -0,0 +1,4 @@
+
+/.idea/
+/target/
+/apache-shiro.iml
\ No newline at end of file
diff --git a/java-security/spring-security/pom.xml b/java-security/spring-security/pom.xml
new file mode 100644
index 0000000000..a2c7430426
--- /dev/null
+++ b/java-security/spring-security/pom.xml
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-security</artifactId>
+    <name>spring-security</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>java-security</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-freemarker</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-security</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>
diff --git a/java-security/spring-security/src/main/java/com/baeldung/springsecurity/Application.java b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/Application.java
new file mode 100644
index 0000000000..318a9a52ec
--- /dev/null
+++ b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/Application.java
@@ -0,0 +1,12 @@
+package com.baeldung.springsecurity;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}
\ No newline at end of file
diff --git a/java-security/spring-security/src/main/java/com/baeldung/springsecurity/config/SecurityConfig.java b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/config/SecurityConfig.java
new file mode 100644
index 0000000000..0516c1fddb
--- /dev/null
+++ b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/config/SecurityConfig.java
@@ -0,0 +1,45 @@
+package com.baeldung.springsecurity.config;
+
+import org.springframework.context.annotation.Bean;
+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;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.security.crypto.password.PasswordEncoder;
+
+@EnableWebSecurity
+public class SecurityConfig extends WebSecurityConfigurerAdapter {
+
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+        http.authorizeRequests(authorize -> authorize.antMatchers("/index", "/login")
+            .permitAll()
+            .antMatchers("/home", "/logout")
+            .authenticated()
+            .antMatchers("/admin/**")
+            .hasRole("ADMIN"))
+            .formLogin(formLogin -> formLogin.loginPage("/login")
+                .failureUrl("/login-error"));
+    }
+
+    @Override
+    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
+        auth.inMemoryAuthentication()
+            .withUser("Jerry")
+            .password(passwordEncoder().encode("password"))
+            .authorities("READ", "WRITE")
+            .roles("ADMIN")
+            .and()
+            .withUser("Tom")
+            .password(passwordEncoder().encode("password"))
+            .authorities("READ")
+            .roles("USER");
+    }
+
+    @Bean
+    public PasswordEncoder passwordEncoder() {
+        return new BCryptPasswordEncoder();
+    }
+
+}
diff --git a/java-security/spring-security/src/main/java/com/baeldung/springsecurity/web/SpringController.java b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/web/SpringController.java
new file mode 100644
index 0000000000..d5eafaf954
--- /dev/null
+++ b/java-security/spring-security/src/main/java/com/baeldung/springsecurity/web/SpringController.java
@@ -0,0 +1,79 @@
+package com.baeldung.springsecurity.web;
+
+import java.util.Collection;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.security.authentication.AnonymousAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@Controller
+public class SpringController {
+
+    @GetMapping("/")
+    public String index() {
+        return "index";
+    }
+
+    @GetMapping("/login")
+    public String showLoginPage() {
+        return "login";
+    }
+
+    @RequestMapping("/login-error")
+    public String loginError(Model model) {
+        model.addAttribute("error", "Invalid Credentials");
+        return "login";
+    }
+
+    @PostMapping("/login")
+    public String doLogin(HttpServletRequest req) {
+        return "redirect:/home";
+    }
+
+    @GetMapping("/home")
+    public String showHomePage(HttpServletRequest req, Model model) {
+        addUserAttributes(model);
+        return "home";
+    }
+
+    @GetMapping("/admin")
+    public String adminOnly(HttpServletRequest req, Model model) {
+        addUserAttributes(model);
+        model.addAttribute("adminContent", "only admin can view this");
+        return "home";
+    }
+
+    private void addUserAttributes(Model model) {
+        Authentication auth = SecurityContextHolder.getContext()
+            .getAuthentication();
+        if (auth != null && !auth.getClass()
+            .equals(AnonymousAuthenticationToken.class)) {
+            User user = (User) auth.getPrincipal();
+            model.addAttribute("username", user.getUsername());
+
+            Collection<GrantedAuthority> authorities = user.getAuthorities();
+
+            for (GrantedAuthority authority : authorities) {
+                if (authority.getAuthority()
+                    .contains("USER")) {
+                    model.addAttribute("role", "USER");
+                    model.addAttribute("permissions", "READ");
+                } else if (authority.getAuthority()
+                    .contains("ADMIN")) {
+                    model.addAttribute("role", "ADMIN");
+                    model.addAttribute("permissions", "READ WRITE");
+                }
+            }
+        }
+    }
+
+}
diff --git a/java-security/spring-security/src/main/resources/application.yml b/java-security/spring-security/src/main/resources/application.yml
new file mode 100644
index 0000000000..d2cbd10a91
--- /dev/null
+++ b/java-security/spring-security/src/main/resources/application.yml
@@ -0,0 +1,12 @@
+server:
+  port: 8080
+
+logging:
+  level:
+    root: WARN
+    org.springframework.web: INFO
+    org.springframework.security: INFO
+
+spring:
+  freemarker:
+    suffix: .ftl
diff --git a/java-security/spring-security/src/main/resources/templates/home.ftl b/java-security/spring-security/src/main/resources/templates/home.ftl
new file mode 100644
index 0000000000..dcf6d96d50
--- /dev/null
+++ b/java-security/spring-security/src/main/resources/templates/home.ftl
@@ -0,0 +1,20 @@
+<html>
+<head>
+    <title>Home Page</title>
+</head>
+<body style="margin-left: 30px;">
+<h1>Welcome ${username}!</h1>
+<p><strong>Role</strong>: ${role}</p>
+<p><strong>Permissions</strong></p>
+<p>${permissions}</p>
+<a href="/admin">Admin only</a>
+<#if adminContent??>
+  ${adminContent}
+</#if>
+<br>
+<form role="form" action="/logout" method="POST">
+   <input type="Submit" value="Logout" />
+   <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>
+</form>
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/spring-security/src/main/resources/templates/index.ftl b/java-security/spring-security/src/main/resources/templates/index.ftl
new file mode 100644
index 0000000000..8f35c0af1b
--- /dev/null
+++ b/java-security/spring-security/src/main/resources/templates/index.ftl
@@ -0,0 +1,10 @@
+<html>
+<head>
+    <title>Index</title>
+</head>
+<body>
+    <h1>Welcome Guest!</h1>
+    <br>
+    Go to the <a href="/home">secured page
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/spring-security/src/main/resources/templates/login.ftl b/java-security/spring-security/src/main/resources/templates/login.ftl
new file mode 100644
index 0000000000..266b5dfb80
--- /dev/null
+++ b/java-security/spring-security/src/main/resources/templates/login.ftl
@@ -0,0 +1,26 @@
+<html>
+<head>
+    <title>Login</title>
+</head>
+<body style="margin-left: 30px;">
+<h3>Login</h3>
+<br>
+<form action="/login" method="post">
+    <#if (error?length > 0)??>
+        <p style="color:darkred;">${error}</p>
+    <#else>
+    </#if>
+
+    <label for="username">Username</label>
+    <br>
+    <input type="text" name="username">
+    <br><br>
+    <label for="password">Password</label>
+    <br>
+    <input type="password" name="password">
+    <br><br>
+    <input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>
+    <input type="submit" value="Submit">
+</form>
+</body>
+</html>
\ No newline at end of file
diff --git a/java-security/spring-security/src/test/java/com/baeldung/springsecurity/SpringContextTest.java b/java-security/spring-security/src/test/java/com/baeldung/springsecurity/SpringContextTest.java
new file mode 100644
index 0000000000..a3adfa30c4
--- /dev/null
+++ b/java-security/spring-security/src/test/java/com/baeldung/springsecurity/SpringContextTest.java
@@ -0,0 +1,17 @@
+package com.baeldung.springsecurity;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@SpringBootTest(classes = { Application.class })
+public class SpringContextTest {
+
+    @Test
+    public void whenSpringContextIsBootstrapped_thenNoExceptions() {
+
+    }
+
+}
\ No newline at end of file