Fix conflicts in date diff

apache-shiro/pom.xml

@@ -9,9 +9,9 @@
     <version>1.0-SNAPSHOT</version>
 
     <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.5.2.RELEASE</version>
     </parent>
 
     <properties>
@@ -21,6 +21,19 @@
     </properties>
 
     <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.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>

apache-shiro/src/main/java/com/baeldung/ShiroSpringApplication.java

@@ -0,0 +1,45 @@
+package com.baeldung;
+
+import org.apache.shiro.realm.Realm;
+import org.apache.shiro.spring.web.config.DefaultShiroFilterChainDefinition;
+import org.apache.shiro.spring.web.config.ShiroFilterChainDefinition;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+/**
+ * Created by smatt on 21/08/2017.
+ */
+@SpringBootApplication
+public class ShiroSpringApplication {
+
+    private static final transient Logger log = LoggerFactory.getLogger(ShiroSpringApplication.class);
+
+    public static void main(String... args) {
+        SpringApplication.run(ShiroSpringApplication.class, args);
+    }
+
+
+    @Bean
+    public Realm realm() {
+        return new MyCustomRealm();
+    }
+
+
+    @Bean
+    public ShiroFilterChainDefinition shiroFilterChainDefinition() {
+        DefaultShiroFilterChainDefinition filter
+          = new DefaultShiroFilterChainDefinition();
+
+        filter.addPathDefinition("/secure", "authc");
+        filter.addPathDefinition("/**", "anon");
+
+        return filter;
+    }
+
+
+
+
+}

apache-shiro/src/main/java/com/baeldung/controllers/ShiroSpringController.java

@@ -0,0 +1,105 @@
+package com.baeldung.controllers;
+
+import com.baeldung.models.UserCredentials;
+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.ModelMap;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
+
+import javax.servlet.http.HttpServletRequest;
+
+@Controller
+public class ShiroSpringController {
+
+
+
+    @GetMapping("/")
+    public String index() {
+       return "index";
+    }
+
+
+    @RequestMapping( value = "/login", method = {RequestMethod.GET, RequestMethod.POST})
+    public String login(HttpServletRequest req, UserCredentials cred, RedirectAttributes attr) {
+
+      if(req.getMethod().equals(RequestMethod.GET.toString())) {
+        return "login";
+      }
+      else {
+
+        Subject subject = SecurityUtils.getSubject();
+
+        if(!subject.isAuthenticated()) {
+          UsernamePasswordToken token = new UsernamePasswordToken(
+            cred.getUsername(), cred.getPassword(), cred.isRememberMe());
+          try {
+            subject.login(token);
+          } catch (AuthenticationException ae) {
+              ae.printStackTrace();
+              attr.addFlashAttribute("error", "Invalid Credentials");
+              return "redirect:/login";
+          }
+        }
+
+        return "redirect:/secure";
+      }
+    }
+
+
+    @GetMapping("/secure")
+    public String secure(ModelMap modelMap) {
+
+        Subject currentUser = SecurityUtils.getSubject();
+        String role = "", permission = "";
+
+        if(currentUser.hasRole("admin")) {
+            role = role  + "You are an Admin";
+        }
+        else if(currentUser.hasRole("editor")) {
+            role = role + "You are an Editor";
+        }
+        else if(currentUser.hasRole("author")) {
+            role = role + "You are an Author";
+        }
+
+        if(currentUser.isPermitted("articles:compose")) {
+            permission = permission + "You can compose an article, ";
+        } else {
+            permission = permission + "You are not permitted to compose an article!, ";
+        }
+
+        if(currentUser.isPermitted("articles:save")) {
+            permission = permission + "You can save articles, ";
+        } else {
+            permission = permission + "\nYou can not save articles, ";
+        }
+
+        if(currentUser.isPermitted("articles:publish")) {
+            permission = permission  + "\nYou can publish articles";
+        } else {
+            permission = permission + "\nYou can not publish articles";
+        }
+
+        modelMap.addAttribute("username", currentUser.getPrincipal());
+        modelMap.addAttribute("permission", permission);
+        modelMap.addAttribute("role", role);
+
+        return "secure";
+    }
+
+
+    @PostMapping("/logout")
+    public String logout() {
+       Subject subject = SecurityUtils.getSubject();
+       subject.logout();
+       return "redirect:/";
+    }
+
+}

apache-shiro/src/main/java/com/baeldung/models/UserCredentials.java

@@ -0,0 +1,40 @@
+package com.baeldung.models;
+
+public class UserCredentials {
+
+    private String username;
+    private String password;
+    private boolean rememberMe = false;
+
+    public UserCredentials() {}
+
+    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;
+    }
+
+    public boolean isRememberMe() {
+        return rememberMe;
+    }
+
+    public void setRememberMe(boolean rememberMe) {
+        this.rememberMe = rememberMe;
+    }
+
+    @Override
+    public String toString() {
+        return "username = " + getUsername()
+                + "\nrememberMe = " + isRememberMe();
+    }
+}

apache-shiro/src/main/resources/application.properties

@@ -0,0 +1,11 @@
+server.port=9000
+server.servlet-path=/
+server.context-path=/
+
+#shiro-spring-boot-config
+shiro.loginUrl = /login
+shiro.successUrl = /secure
+shiro.unauthorizedUrl = /login
+
+#freemarker
+spring.freemarker.suffix=.ftl

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>

apache-shiro/src/main/resources/templates/login.ftl

@@ -0,0 +1,27 @@
+<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="checkbox" name="rememberMe"> Remember Me
+    <br><br>
+    <input type="submit" value="Submit">
+</form>
+</body>
+</html>

apache-shiro/src/main/resources/templates/secure.ftl

@@ -0,0 +1,15 @@
+<html>
+<head>
+    <title>Secure</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>
+<br>
+<form role="form" action="/logout" method="POST">
+   <input type="Submit" value="Logout" />
+</form>
+</body>
+</html>

core-java-concurrency/.gitignore

@@ -0,0 +1,26 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+*.txt
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml

core-java-concurrency/README.md

@@ -0,0 +1,32 @@
+=========
+
+## Core Java Concurrency Examples
+
+### Relevant Articles: 
+- [Guide To CompletableFuture](http://www.baeldung.com/java-completablefuture)
+- [A Guide to the Java ExecutorService](http://www.baeldung.com/java-executor-service-tutorial)
+- [Introduction to Thread Pools in Java](http://www.baeldung.com/thread-pool-java-and-guava)
+- [Guide to java.util.concurrent.Future](http://www.baeldung.com/java-future)
+- [Guide to java.util.concurrent.BlockingQueue](http://www.baeldung.com/java-blocking-queue)
+- [Guide to CountDownLatch in Java](http://www.baeldung.com/java-countdown-latch)
+- [A Guide to ConcurrentMap](http://www.baeldung.com/java-concurrent-map)
+- [Guide to PriorityBlockingQueue in Java](http://www.baeldung.com/java-priority-blocking-queue)
+- [Avoiding the ConcurrentModificationException in Java](http://www.baeldung.com/java-concurrentmodificationexception)
+- [Custom Thread Pools In Java 8 Parallel Streams](http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)
+- [Guide to java.util.concurrent.Locks](http://www.baeldung.com/java-concurrent-locks)
+- [An Introduction to ThreadLocal in Java](http://www.baeldung.com/java-threadlocal)
+- [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
+- [A Guide to Java SynchronousQueue](http://www.baeldung.com/java-synchronous-queue)
+- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
+- [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
+- [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
+- [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
+- [The Dining Philosophers Problem in Java](http://www.baeldung.com/java-dining-philoshophers)
+- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)
+- [Guide to the Java Phaser](http://www.baeldung.com/java-phaser)
+- [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
+- [An Introduction to Atomic Variables in Java](http://www.baeldung.com/java-atomic-variables)
+- [CyclicBarrier in Java](http://www.baeldung.com/java-cyclic-barrier)
+- [Guide to Volatile Keyword in Java](http://www.baeldung.com/java-volatile)
+- [Overview of the java.util.concurrent](http://www.baeldung.com/java-util-concurrent)
+- [Semaphores in Java](http://www.baeldung.com/java-semaphore)

core-java-concurrency/pom.xml

@@ -0,0 +1,237 @@
+<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>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-concurrency</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>core-java-concurrency</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+
+        <!-- utils -->
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.version}</version>
+        </dependency>
+
+
+        <!-- test scoped -->
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>com.jayway.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${avaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+    
+    <build>
+        <finalName>core-java-concurrency</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <classpathPrefix>libs/</classpathPrefix>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                        <configuration>
+                            <archiveBaseDirectory>${project.basedir}</archiveBaseDirectory>
+                            <archive>
+                                <manifest>
+                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                                </manifest>
+                            </archive>
+                            <descriptorRefs>
+                                <descriptorRef>jar-with-dependencies</descriptorRef>
+                            </descriptorRefs>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <shadedArtifactAttached>true</shadedArtifactAttached>
+                            <transformers>
+                                <transformer
+                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                                </transformer>
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>com.jolira</groupId>
+                <artifactId>onejar-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <configuration>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                            <attachToBuild>true</attachToBuild>
+                            <filename>${project.build.finalName}-onejar.${project.packaging}</filename>
+                        </configuration>
+                        <goals>
+                            <goal>one-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                        <configuration>
+                            <classifier>spring-boot</classifier>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+
+    </build>
+
+    <profiles>
+        <profile>
+            <id>integration</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <excludes>
+                                        <exclude>**/*ManualTest.java</exclude>
+                                    </excludes>
+                                    <includes>
+                                        <include>**/*IntegrationTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+    
+    <properties>
+
+        <!-- util -->
+        <guava.version>21.0</guava.version>
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <commons-math3.version>3.6.1</commons-math3.version>
+        <commons-io.version>2.5</commons-io.version>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <collections-generic.version>4.01</collections-generic.version>
+
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <avaitility.version>1.7.0</avaitility.version>
+
+    </properties>
+</project>

core-java-concurrency/src/main/java/com/baeldung/concurrent/atomic/SafeCounterWithLock.java

@@ -3,11 +3,11 @@ package com.baeldung.concurrent.atomic;
 public class SafeCounterWithLock {
     private volatile int counter;
     
-    public int getValue() {
+    int getValue() {
         return counter;
     }
     
-    public synchronized void increment() {
+    synchronized void increment() {
         counter++;
     }
 }

core-java-concurrency/src/main/java/com/baeldung/concurrent/atomic/SafeCounterWithoutLock.java

@@ -5,11 +5,11 @@ import java.util.concurrent.atomic.AtomicInteger;
 public class SafeCounterWithoutLock {
     private final AtomicInteger counter = new AtomicInteger(0);
     
-    public int getValue() {
+    int getValue() {
         return counter.get();
     }
     
-    public void increment() {
+    void increment() {
         while(true) {
             int existingValue = getValue();
             int newValue = existingValue + 1;

core-java-concurrency/src/main/java/com/baeldung/concurrent/atomic/UnsafeCounter.java

@@ -1,13 +1,13 @@
 package com.baeldung.concurrent.atomic;
 
 public class UnsafeCounter {
-    int counter;
+    private int counter;
     
-    public int getValue() {
+    int getValue() {
         return counter;
     }
     
-    public void increment() {
+    void increment() {
         counter++;
     }
 }

core-java-concurrency/src/main/java/com/baeldung/threadlocal/Context.java

@@ -4,14 +4,14 @@ package com.baeldung.threadlocal;
 public class Context {
     private final String userName;
 
-    public Context(String userName) {
+    Context(String userName) {
         this.userName = userName;
     }
 
     @Override
     public String toString() {
         return "Context{" +
-                "userNameSecret='" + userName + '\'' +
-                '}';
+          "userNameSecret='" + userName + '\'' +
+          '}';
     }
 }

core-java-concurrency/src/main/java/com/baeldung/threadlocal/SharedMapWithUserContext.java

@@ -5,11 +5,11 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
 public class SharedMapWithUserContext implements Runnable {
-    public final static Map<Integer, Context> userContextPerUserId = new ConcurrentHashMap<>();
+    final static Map<Integer, Context> userContextPerUserId = new ConcurrentHashMap<>();
     private final Integer userId;
     private UserRepository userRepository = new UserRepository();
 
-    public SharedMapWithUserContext(Integer userId) {
+    SharedMapWithUserContext(Integer userId) {
         this.userId = userId;
     }
 

core-java-concurrency/src/main/java/com/baeldung/threadlocal/ThreadLocalWithUserContext.java

@@ -10,7 +10,7 @@ public class ThreadLocalWithUserContext implements Runnable {
     private final Integer userId;
     private UserRepository userRepository = new UserRepository();
 
-    public ThreadLocalWithUserContext(Integer userId) {
+    ThreadLocalWithUserContext(Integer userId) {
         this.userId = userId;
     }
 

core-java-concurrency/src/main/java/com/baeldung/threadlocal/UserRepository.java

@@ -4,7 +4,7 @@ import java.util.UUID;
 
 
 public class UserRepository {
-    public String getUserNameForUserId(Integer userId) {
+    String getUserNameForUserId(Integer userId) {
         return UUID.randomUUID().toString();
     }
 }

core-java-concurrency/src/main/java/com/baeldung/threadpool/CountingTask.java

@@ -2,19 +2,21 @@ package com.baeldung.threadpool;
 
 import java.util.concurrent.ForkJoinTask;
 import java.util.concurrent.RecursiveTask;
-import java.util.stream.Collectors;
 
 public class CountingTask extends RecursiveTask<Integer> {
 
     private final TreeNode node;
 
-    public CountingTask(TreeNode node) {
+    CountingTask(TreeNode node) {
         this.node = node;
     }
 
     @Override
     protected Integer compute() {
-        return node.value + node.children.stream().map(childNode -> new CountingTask(childNode).fork()).collect(Collectors.summingInt(ForkJoinTask::join));
+        return node.getValue() + node.getChildren().stream()
+          .map(childNode -> new CountingTask(childNode).fork())
+          .mapToInt(ForkJoinTask::join)
+          .sum();
     }
 
 }

core-java-concurrency/src/main/java/com/baeldung/threadpool/TreeNode.java

@@ -0,0 +1,25 @@
+package com.baeldung.threadpool;
+
+import com.google.common.collect.Sets;
+
+import java.util.Set;
+
+public class TreeNode {
+
+    private int value;
+
+    private Set<TreeNode> children;
+
+    TreeNode(int value, TreeNode... children) {
+        this.value = value;
+        this.children = Sets.newHashSet(children);
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    public Set<TreeNode> getChildren() {
+        return children;
+    }
+}

core-java-concurrency/src/main/java/com/baeldung/transferqueue/Consumer.java

@@ -11,10 +11,10 @@ public class Consumer implements Runnable {
 
     private final TransferQueue<String> transferQueue;
     private final String name;
-    private final int numberOfMessagesToConsume;
-    public final AtomicInteger numberOfConsumedMessages = new AtomicInteger();
+    final int numberOfMessagesToConsume;
+    final AtomicInteger numberOfConsumedMessages = new AtomicInteger();
 
-    public Consumer(TransferQueue<String> transferQueue, String name, int numberOfMessagesToConsume) {
+    Consumer(TransferQueue<String> transferQueue, String name, int numberOfMessagesToConsume) {
         this.transferQueue = transferQueue;
         this.name = name;
         this.numberOfMessagesToConsume = numberOfMessagesToConsume;

core-java-concurrency/src/main/java/com/baeldung/transferqueue/Producer.java

@@ -12,10 +12,10 @@ public class Producer implements Runnable {
 
     private final TransferQueue<String> transferQueue;
     private final String name;
-    private final Integer numberOfMessagesToProduce;
-    public final AtomicInteger numberOfProducedMessages = new AtomicInteger();
+    final Integer numberOfMessagesToProduce;
+    final AtomicInteger numberOfProducedMessages = new AtomicInteger();
 
-    public Producer(TransferQueue<String> transferQueue, String name, Integer numberOfMessagesToProduce) {
+    Producer(TransferQueue<String> transferQueue, String name, Integer numberOfMessagesToProduce) {
         this.transferQueue = transferQueue;
         this.name = name;
         this.numberOfMessagesToProduce = numberOfMessagesToProduce;

core-java-concurrency/src/main/java/log4j.properties

@@ -0,0 +1,9 @@
+# Set root logger level to DEBUG and its only appender to A1.
+log4j.rootLogger=DEBUG, A1
+
+# A1 is set to be a ConsoleAppender.
+log4j.appender.A1=org.apache.log4j.ConsoleAppender
+
+# A1 uses PatternLayout.
+log4j.appender.A1.layout=org.apache.log4j.PatternLayout
+log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n

core-java-concurrency/src/main/resources/logback.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>web - %date [%thread] %-5level %logger{36} - %message%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <logger name="org.springframework" level="WARN" />
+    <logger name="org.springframework.transaction" level="WARN" />
+
+    <!-- in order to debug some marshalling issues, this needs to be TRACE -->
+    <logger name="org.springframework.web.servlet.mvc" level="WARN" />
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

core-java-concurrency/src/test/java/com/baeldung/completablefuture/CompletableFutureLongRunningUnitTest.java

@@ -4,7 +4,11 @@ import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.concurrent.*;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 

core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchExampleIntegrationTest.java

@@ -18,7 +18,9 @@ public class CountdownLatchExampleIntegrationTest {
         // Given
         List<String> outputScraper = Collections.synchronizedList(new ArrayList<>());
         CountDownLatch countDownLatch = new CountDownLatch(5);
-        List<Thread> workers = Stream.generate(() -> new Thread(new Worker(outputScraper, countDownLatch))).limit(5).collect(toList());
+        List<Thread> workers = Stream.generate(() -> new Thread(new Worker(outputScraper, countDownLatch)))
+          .limit(5)
+          .collect(toList());
 
         // When
         workers.forEach(Thread::start);
@@ -26,7 +28,6 @@ public class CountdownLatchExampleIntegrationTest {
         outputScraper.add("Latch released");
 
         // Then
-        outputScraper.forEach(Object::toString);
         assertThat(outputScraper).containsExactly("Counted down", "Counted down", "Counted down", "Counted down", "Counted down", "Latch released");
     }
 
@@ -35,7 +36,9 @@ public class CountdownLatchExampleIntegrationTest {
         // Given
         List<String> outputScraper = Collections.synchronizedList(new ArrayList<>());
         CountDownLatch countDownLatch = new CountDownLatch(5);
-        List<Thread> workers = Stream.generate(() -> new Thread(new BrokenWorker(outputScraper, countDownLatch))).limit(5).collect(toList());
+        List<Thread> workers = Stream.generate(() -> new Thread(new BrokenWorker(outputScraper, countDownLatch)))
+          .limit(5)
+          .collect(toList());
 
         // When
         workers.forEach(Thread::start);
@@ -63,7 +66,6 @@ public class CountdownLatchExampleIntegrationTest {
         outputScraper.add("Workers complete");
 
         // Then
-        outputScraper.forEach(Object::toString);
         assertThat(outputScraper).containsExactly("Workers ready", "Counted down", "Counted down", "Counted down", "Counted down", "Counted down", "Workers complete");
     }
 

core-java-concurrency/src/test/java/com/baeldung/concurrent/future/SquareCalculatorIntegrationTest.java

@@ -22,7 +22,6 @@ public class SquareCalculatorIntegrationTest {
 
     private static final Logger LOG = LoggerFactory.getLogger(SquareCalculatorIntegrationTest.class);
 
-
     @Rule
     public TestName name = new TestName();
 

core-java-concurrency/src/test/java/com/baeldung/concurrent/locks/SynchronizedHashMapWithRWLockManualTest.java

@@ -49,9 +49,7 @@ public class SynchronizedHashMapWithRWLockManualTest {
 
     private void executeReaderThreads(SynchronizedHashMapWithRWLock object, int threadCount, ExecutorService service) {
         for (int i = 0; i < threadCount; i++)
-            service.execute(() -> {
-                object.get("key" + threadCount);
-            });
+            service.execute(() -> object.get("key" + threadCount));
     }
 
 }

core-java-concurrency/src/test/java/com/baeldung/java/concurrentmap/ConcurrentMapNullKeyValueManualTest.java

@@ -12,7 +12,7 @@ import static org.junit.Assert.assertNull;
 
 public class ConcurrentMapNullKeyValueManualTest {
 
-    ConcurrentMap<String, Object> concurrentMap;
+    private ConcurrentMap<String, Object> concurrentMap;
 
     @Before
     public void setup() {

core-java-concurrency/src/test/java/com/baeldung/java/concurrentmap/ConcurrentMapPerformanceManualTest.java

@@ -1,27 +1,31 @@
 package com.baeldung.java.concurrentmap;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Hashtable;
 import java.util.Map;
-import java.util.concurrent.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import org.junit.Test;
 
 public class ConcurrentMapPerformanceManualTest {
 
     @Test
     public void givenMaps_whenGetPut500KTimes_thenConcurrentMapFaster() throws Exception {
-        Map<String, Object> hashtable = new Hashtable<>();
-        Map<String, Object> synchronizedHashMap = Collections.synchronizedMap(new HashMap<>());
-        Map<String, Object> concurrentHashMap = new ConcurrentHashMap<>();
+        final Map<String, Object> hashtable = new Hashtable<>();
+        final Map<String, Object> synchronizedHashMap = Collections.synchronizedMap(new HashMap<>());
+        final Map<String, Object> concurrentHashMap = new ConcurrentHashMap<>();
 
-        long hashtableAvgRuntime = timeElapseForGetPut(hashtable);
-        long syncHashMapAvgRuntime = timeElapseForGetPut(synchronizedHashMap);
-        long concurrentHashMapAvgRuntime = timeElapseForGetPut(concurrentHashMap);
+        final long hashtableAvgRuntime = timeElapseForGetPut(hashtable);
+        final long syncHashMapAvgRuntime = timeElapseForGetPut(synchronizedHashMap);
+        final long concurrentHashMapAvgRuntime = timeElapseForGetPut(concurrentHashMap);
 
         System.out.println(String.format("Hashtable: %s, syncHashMap: %s, ConcurrentHashMap: %s", hashtableAvgRuntime, syncHashMapAvgRuntime, concurrentHashMapAvgRuntime));
 
@@ -31,13 +35,13 @@ public class ConcurrentMapPerformanceManualTest {
     }
 
     private long timeElapseForGetPut(Map<String, Object> map) throws InterruptedException {
-        ExecutorService executorService = Executors.newFixedThreadPool(4);
-        long startTime = System.nanoTime();
+        final ExecutorService executorService = Executors.newFixedThreadPool(4);
+        final long startTime = System.nanoTime();
         for (int i = 0; i < 4; i++) {
             executorService.execute(() -> {
                 for (int j = 0; j < 500_000; j++) {
-                    int value = ThreadLocalRandom.current().nextInt(10000);
-                    String key = String.valueOf(value);
+                    final int value = ThreadLocalRandom.current().nextInt(10000);
+                    final String key = String.valueOf(value);
                     map.put(key, value);
                     map.get(key);
                 }
@@ -56,11 +60,11 @@ public class ConcurrentMapPerformanceManualTest {
                 return 1;
             }
         }
-        int executeTimes = 5000;
+        final int executeTimes = 5000;
 
-        Map<SameHash, Integer> mapOfSameHash = new ConcurrentHashMap<>();
+        final Map<SameHash, Integer> mapOfSameHash = new ConcurrentHashMap<>();
         ExecutorService executorService = Executors.newFixedThreadPool(2);
-        long sameHashStartTime = System.currentTimeMillis();
+        final long sameHashStartTime = System.currentTimeMillis();
         for (int i = 0; i < 2; i++) {
             executorService.execute(() -> {
                 for (int j = 0; j < executeTimes; j++) {
@@ -71,10 +75,10 @@ public class ConcurrentMapPerformanceManualTest {
         executorService.shutdown();
         executorService.awaitTermination(5, TimeUnit.SECONDS);
 
-        long mapOfSameHashDuration = System.currentTimeMillis() - sameHashStartTime;
-        Map<Object, Integer> mapOfDefaultHash = new ConcurrentHashMap<>();
+        final long mapOfSameHashDuration = System.currentTimeMillis() - sameHashStartTime;
+        final Map<Object, Integer> mapOfDefaultHash = new ConcurrentHashMap<>();
         executorService = Executors.newFixedThreadPool(2);
-        long defaultHashStartTime = System.currentTimeMillis();
+        final long defaultHashStartTime = System.currentTimeMillis();
         for (int i = 0; i < 2; i++) {
             executorService.execute(() -> {
                 for (int j = 0; j < executeTimes; j++) {
@@ -85,11 +89,11 @@ public class ConcurrentMapPerformanceManualTest {
         executorService.shutdown();
         executorService.awaitTermination(5, TimeUnit.SECONDS);
 
-        long mapOfDefaultHashDuration = System.currentTimeMillis() - defaultHashStartTime;
+        final long mapOfDefaultHashDuration = System.currentTimeMillis() - defaultHashStartTime;
         assertEquals(executeTimes * 2, mapOfDefaultHash.size());
         assertEquals(executeTimes * 2, mapOfSameHash.size());
         System.out.println(String.format("same-hash: %s, default-hash: %s", mapOfSameHashDuration, mapOfDefaultHashDuration));
-        assertTrue("same hashCode() should greatly degrade performance", mapOfSameHashDuration > mapOfDefaultHashDuration * 10);
+        assertTrue("same hashCode() should greatly degrade performance", mapOfSameHashDuration > (mapOfDefaultHashDuration * 10));
     }
 
 }

core-java-concurrency/src/test/java/com/baeldung/java/concurrentmap/ConcurrentNavigableMapManualTest.java

@@ -18,7 +18,7 @@ public class ConcurrentNavigableMapManualTest {
     public void givenSkipListMap_whenAccessInMultiThreads_thenOrderingStable() throws InterruptedException {
         NavigableMap<Integer, String> skipListMap = new ConcurrentSkipListMap<>();
 
-        updateMapConcurrently(skipListMap, 4);
+        updateMapConcurrently(skipListMap);
 
         Iterator<Integer> skipListIter = skipListMap.keySet().iterator();
         int previous = skipListIter.next();
@@ -28,9 +28,9 @@ public class ConcurrentNavigableMapManualTest {
         }
     }
 
-    private void updateMapConcurrently(NavigableMap<Integer, String> navigableMap, int concurrencyLevel) throws InterruptedException {
-        ExecutorService executorService = Executors.newFixedThreadPool(concurrencyLevel);
-        for (int i = 0; i < concurrencyLevel; i++) {
+    private void updateMapConcurrently(NavigableMap<Integer, String> navigableMap) throws InterruptedException {
+        ExecutorService executorService = Executors.newFixedThreadPool(4);
+        for (int i = 0; i < 4; i++) {
             executorService.execute(() -> {
                 ThreadLocalRandom random = ThreadLocalRandom.current();
                 for (int j = 0; j < 10000; j++) {
@@ -45,26 +45,26 @@ public class ConcurrentNavigableMapManualTest {
     @Test
     public void givenSkipListMap_whenNavConcurrently_thenCountCorrect() throws InterruptedException {
         NavigableMap<Integer, Integer> skipListMap = new ConcurrentSkipListMap<>();
-        int count = countMapElementByPollingFirstEntry(skipListMap, 10000, 4);
+        int count = countMapElementByPollingFirstEntry(skipListMap);
         assertEquals(10000 * 4, count);
     }
 
     @Test
     public void givenTreeMap_whenNavConcurrently_thenCountError() throws InterruptedException {
         NavigableMap<Integer, Integer> treeMap = new TreeMap<>();
-        int count = countMapElementByPollingFirstEntry(treeMap, 10000, 4);
+        int count = countMapElementByPollingFirstEntry(treeMap);
         assertNotEquals(10000 * 4, count);
     }
 
-    private int countMapElementByPollingFirstEntry(NavigableMap<Integer, Integer> navigableMap, int elementCount, int concurrencyLevel) throws InterruptedException {
-        for (int i = 0; i < elementCount * concurrencyLevel; i++) {
+    private int countMapElementByPollingFirstEntry(NavigableMap<Integer, Integer> navigableMap) throws InterruptedException {
+        for (int i = 0; i < 10000 * 4; i++) {
             navigableMap.put(i, i);
         }
         AtomicInteger counter = new AtomicInteger(0);
-        ExecutorService executorService = Executors.newFixedThreadPool(concurrencyLevel);
-        for (int j = 0; j < concurrencyLevel; j++) {
+        ExecutorService executorService = Executors.newFixedThreadPool(4);
+        for (int j = 0; j < 4; j++) {
             executorService.execute(() -> {
-                for (int i = 0; i < elementCount; i++) {
+                for (int i = 0; i < 10000; i++) {
                     if (navigableMap.pollFirstEntry() != null) {
                         counter.incrementAndGet();
                     }

core-java-concurrency/src/test/java/com/baeldung/java/concurrentmodification/ConcurrentModificationUnitTest.java

@@ -2,7 +2,6 @@ package com.baeldung.java.concurrentmodification;
 
 import org.junit.Test;
 
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.ConcurrentModificationException;
 import java.util.Iterator;
@@ -28,9 +27,9 @@ public class ConcurrentModificationUnitTest {
 
         List<Integer> integers = newArrayList(1, 2, 3);
 
-        for (Iterator<Integer> iterator = integers.iterator(); iterator.hasNext();) {
+        for (Iterator<Integer> iterator = integers.iterator(); iterator.hasNext(); ) {
             Integer integer = iterator.next();
-            if(integer == 2) {
+            if (integer == 2) {
                 iterator.remove();
             }
         }
@@ -45,7 +44,7 @@ public class ConcurrentModificationUnitTest {
         List<Integer> toRemove = newArrayList();
 
         for (Integer integer : integers) {
-            if(integer == 2) {
+            if (integer == 2) {
                 toRemove.add(integer);
             }
         }
@@ -69,10 +68,10 @@ public class ConcurrentModificationUnitTest {
         Collection<Integer> integers = newArrayList(1, 2, 3);
 
         List<String> collected = integers
-                .stream()
-                .filter(i -> i != 2)
-                .map(Object::toString)
-                .collect(toList());
+          .stream()
+          .filter(i -> i != 2)
+          .map(Object::toString)
+          .collect(toList());
 
         assertThat(collected).containsExactly("1", "3");
     }

core-java-concurrency/src/test/java/com/baeldung/java8/Java8ExecutorServiceIntegrationTest.java

@@ -72,7 +72,7 @@ public class Java8ExecutorServiceIntegrationTest {
 
         assertTrue(threadPoolExecutor.isShutdown());
         assertFalse(notExecutedTasks.isEmpty());
-        assertTrue(notExecutedTasks.size() > 0 && notExecutedTasks.size() < 98);
+        assertTrue(notExecutedTasks.size() < 98);
     }
 
     private List<Runnable> smartShutdown(ExecutorService executorService) {

core-java-concurrency/src/test/java/org/baeldung/java/streams/ThreadPoolInParallelStreamIntegrationTest.java

@@ -23,7 +23,10 @@ public class ThreadPoolInParallelStreamIntegrationTest {
         List<Long> aList = LongStream.rangeClosed(firstNum, lastNum).boxed().collect(Collectors.toList());
 
         ForkJoinPool customThreadPool = new ForkJoinPool(4);
-        long actualTotal = customThreadPool.submit(() -> aList.parallelStream().reduce(0L, Long::sum)).get();
+        long actualTotal = customThreadPool
+          .submit(() -> aList.parallelStream()
+            .reduce(0L, Long::sum))
+          .get();
 
         assertEquals((lastNum + firstNum) * lastNum / 2, actualTotal);
     }

core-java-concurrency/src/test/resources/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear