Merge remote-tracking branch 'origin/master'

.gitignore

@@ -31,3 +31,5 @@ spring-openid/src/main/resources/application.properties
 .recommenders/
 /spring-hibernate4/nbproject/
 spring-security-openid/src/main/resources/application.properties
+
+spring-all/*.log

algorithms/README.md

@@ -5,3 +5,4 @@
 - [Ant Colony Optimization](http://www.baeldung.com/java-ant-colony-optimization)
 - [Validating Input With Finite Automata in Java](http://www.baeldung.com/finite-automata-java)
 - [Introduction to Jenetics Library](http://www.baeldung.com/jenetics)
+- [Check If a Number Is Prime in Java](http://www.baeldung.com/java-prime-numbers)

apache-cxf/cxf-aegis/src/test/java/com/baeldung/cxf/aegis/BaeldungTest.java

@@ -3,8 +3,10 @@ package com.baeldung.cxf.aegis;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 
+import org.junit.After;
 import org.junit.Test;
 
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.lang.reflect.Type;
@@ -90,4 +92,12 @@ public class BaeldungTest {
         xmlReader.close();
         return courseRepo;
     }
+
+    @After
+    public void cleanup(){
+        File testFile = new File(fileName);
+        if (testFile.exists()) {
+           testFile.delete();     
+        }
+    }
 }

apache-cxf/cxf-jaxrs-implementation/pom.xml

@@ -54,6 +54,12 @@
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
             <version>${httpclient.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
         </dependency>
     </dependencies>
 </project>

apache-cxf/cxf-spring/pom.xml

@@ -24,6 +24,12 @@
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
             <version>${spring.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>

apache-fop/pom.xml

@@ -28,11 +28,6 @@
             <version>${org.slf4j.version}</version>
             <!-- <scope>runtime</scope> --> <!-- some spring dependencies need to compile against jcl -->
         </dependency>
-        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
 
         <!-- test scoped -->
 
@@ -78,6 +73,10 @@
                     <groupId>org.apache.avalon.framework</groupId>
                     <artifactId>avalon-framework-impl</artifactId>
                 </exclusion>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>                
             </exclusions>
         </dependency>
 
@@ -90,6 +89,12 @@
             <groupId>avalon-framework</groupId>
             <artifactId>avalon-framework-impl</artifactId>
             <version>${avalon-framework.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>
 
         <dependency>

apache-poi/pom.xml

@@ -42,6 +42,12 @@
             <groupId>org.jxls</groupId>
             <artifactId>jxls-jexcel</artifactId>
             <version>${jexcel.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>	
     </dependencies>
 </project>

apache-poi/src/test/java/com/baeldung/jexcel/JExcelTest.java

@@ -19,6 +19,7 @@ import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 import org.junit.Before;
+import org.junit.After;
 
 public class JExcelTest {
 
@@ -53,4 +54,11 @@ public class JExcelTest {
             .get(1));
     }
 
+    @After
+    public void cleanup(){
+        File testFile = new File(fileLocation);
+        if (testFile.exists()) {
+           testFile.delete();     
+        }
+    }
 }

apache-poi/src/test/java/com/baeldung/poi/excel/ExcelTest.java

@@ -16,6 +16,7 @@ import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 import org.junit.Before;
+import org.junit.After;
 
 public class ExcelTest {
 
@@ -50,4 +51,11 @@ public class ExcelTest {
             .get(1));
     }
 
+    @After
+    public void cleanup(){
+        File testFile = new File(fileLocation);
+        if (testFile.exists()) {
+           testFile.delete();     
+        }
+    }
 }

apache-thrift/pom.xml

@@ -19,6 +19,12 @@
             <groupId>org.apache.thrift</groupId>
             <artifactId>libthrift</artifactId>
             <version>${thrift.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>
 
         <dependency>

apache-velocity/pom.xml

@@ -38,7 +38,7 @@
         <dependency>
             <groupId>org.apache.velocity</groupId>
             <artifactId>velocity-tools</artifactId>
-            <version>${velocity-tools-version}</version>
+            <version>${velocity-tools-version}</version>        
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
@@ -55,6 +55,12 @@
             <artifactId>httpclient</artifactId>
             <version>${org.apache.httpcomponents.version}</version>
             <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>
     </dependencies>
     <build>

aspectj/pom.xml

@@ -58,7 +58,7 @@
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-core</artifactId>
-            <version>4.3.4.RELEASE</version>
+            <version>4.3.4.RELEASE</version>         
         </dependency>
         <dependency>
             <groupId>cglib</groupId>

aws/pom.xml

@@ -19,12 +19,24 @@
 			<groupId>com.amazonaws</groupId>
 			<artifactId>aws-lambda-java-core</artifactId>
 			<version>${aws-lambda-java-core.version}</version>
+			<exclusions>
+				<exclusion>
+				    <artifactId>commons-logging</artifactId>
+				    <groupId>commons-logging</groupId>
+				</exclusion>
+			</exclusions>
 		</dependency>
 
 		<dependency>
 			<groupId>com.amazonaws</groupId>
 			<artifactId>aws-lambda-java-events</artifactId>
 			<version>${aws-lambda-java-events.version}</version>
+			<exclusions>
+				<exclusion>
+				    <artifactId>commons-logging</artifactId>
+				    <groupId>commons-logging</groupId>
+				</exclusion>
+			</exclusions>			
 		</dependency>
 
 		<dependency>

cdi/pom.xml

@@ -12,6 +12,12 @@
             <groupId>org.springframework</groupId>
             <artifactId>spring-core</artifactId>
             <version>${spring.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>

core-java-9/README.md

@@ -12,3 +12,4 @@
 - [Spring Security – Redirect to the Previous URL After Login](http://www.baeldung.com/spring-security-redirect-login)
 - [Java 9 Process API Improvements](http://www.baeldung.com/java-9-process-api)
 - [Introduction to Java 9 StackWalking API](http://www.baeldung.com/java-9-stackwalking-api)
+- [Introduction to Project Jigsaw](http://www.baeldung.com/project-jigsaw-java-modularity)

core-java/README.md

@@ -92,3 +92,9 @@
 - [Removing all nulls from a List in Java](http://www.baeldung.com/java-remove-nulls-from-list)
 - [Removing all duplicates from a List in Java](http://www.baeldung.com/java-remove-duplicates-from-list)
 - [An Introduction to ThreadLocal in Java](http://www.baeldung.com/java-threadlocal)
+- [Using Math.pow in Java](http://www.baeldung.com/java-math-pow)
+- [Converting Strings to Enums in Java](http://www.baeldung.com/java-string-to-enum)
+- [Flattening Nested Collections in Java](http://www.baeldung.com/java-flatten-nested-collections)
+- [Quick Guide to the Java StringTokenizer](http://www.baeldung.com/java-stringtokenizer)
+- [JVM Log Forging](http://www.baeldung.com/jvm-log-forging)
+- [Guide to sun.misc.Unsafe](http://www.baeldung.com/java-unsafe)

core-java/pom.xml

@@ -92,11 +92,6 @@
             <version>${org.slf4j.version}</version>
             <!-- <scope>runtime</scope> --> <!-- some spring dependencies need to compile against jcl -->
         </dependency>
-        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
@@ -176,6 +171,12 @@
 	    <groupId>org.owasp.esapi</groupId>
 	    <artifactId>esapi</artifactId>
 	    <version>2.1.0.1</version>
+                <exclusions>
+                    <exclusion>
+                        <artifactId>commons-logging</artifactId>
+                        <groupId>commons-logging</groupId>
+                    </exclusion>
+                </exclusions>        
 	</dependency>    
 
     </dependencies>

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

@@ -0,0 +1,36 @@
+package com.baeldung.transferqueue;
+
+import java.util.concurrent.TransferQueue;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Consumer implements Runnable {
+    private final TransferQueue<String> transferQueue;
+    private final String name;
+    private final int numberOfMessagesToConsume;
+    public final AtomicInteger numberOfConsumedMessages = new AtomicInteger();
+
+    public Consumer(TransferQueue<String> transferQueue, String name, int numberOfMessagesToConsume) {
+        this.transferQueue = transferQueue;
+        this.name = name;
+        this.numberOfMessagesToConsume = numberOfMessagesToConsume;
+    }
+
+    @Override
+    public void run() {
+        for (int i = 0; i < numberOfMessagesToConsume; i++) {
+            try {
+                System.out.println("Consumer: " + name + " is waiting to take element...");
+                String element = transferQueue.take();
+                longProcessing(element);
+                System.out.println("Consumer: " + name + " received element: " + element);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private void longProcessing(String element) throws InterruptedException {
+        numberOfConsumedMessages.incrementAndGet();
+        Thread.sleep(500);
+    }
+}

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

@@ -0,0 +1,36 @@
+package com.baeldung.transferqueue;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TransferQueue;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Producer implements Runnable {
+    private final TransferQueue<String> transferQueue;
+    private final String name;
+    private final Integer numberOfMessagesToProduce;
+    public final AtomicInteger numberOfProducedMessages = new AtomicInteger();
+
+    public Producer(TransferQueue<String> transferQueue, String name, Integer numberOfMessagesToProduce) {
+        this.transferQueue = transferQueue;
+        this.name = name;
+        this.numberOfMessagesToProduce = numberOfMessagesToProduce;
+    }
+
+    @Override
+    public void run() {
+        for (int i = 0; i < numberOfMessagesToProduce; i++) {
+            try {
+                System.out.println("Producer: " + name + " is waiting to transfer...");
+                boolean added = transferQueue.tryTransfer("A" + i, 4000, TimeUnit.MILLISECONDS);
+                if (!added) {
+                    System.out.println("can not add an element due to the timeout");
+                } else {
+                    numberOfProducedMessages.incrementAndGet();
+                    System.out.println("Producer: " + name + " transferred element: A" + i);
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}

core-java/src/test/java/com/baeldung/synchronousqueue/SynchronousQueueTest.java

@@ -0,0 +1,83 @@
+package com.baeldung.synchronousqueue;
+
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.junit.runners.MethodSorters;
+
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static junit.framework.TestCase.assertEquals;
+
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class SynchronousQueueTest {
+
+    @Test
+    public void givenTwoThreads_whenWantToExchangeUsingLockGuardedVariable_thenItSucceed() throws InterruptedException {
+        //given
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+        AtomicInteger sharedState = new AtomicInteger();
+        CountDownLatch countDownLatch = new CountDownLatch(1);
+
+        Runnable producer = () -> {
+            Integer producedElement = ThreadLocalRandom.current().nextInt();
+            System.out.println("Saving an element: " + producedElement + " to the exchange point");
+            sharedState.set(producedElement);
+            countDownLatch.countDown();
+        };
+
+        Runnable consumer = () -> {
+            try {
+                countDownLatch.await();
+                Integer consumedElement = sharedState.get();
+                System.out.println("consumed an element: " + consumedElement + " from the exchange point");
+            } catch (InterruptedException ex) {
+                ex.printStackTrace();
+            }
+        };
+
+        //when
+        executor.execute(producer);
+        executor.execute(consumer);
+
+        //then
+        executor.awaitTermination(500, TimeUnit.MILLISECONDS);
+        executor.shutdown();
+        assertEquals(countDownLatch.getCount(), 0);
+    }
+
+    @Test
+    public void givenTwoThreads_whenWantToExchangeUsingSynchronousQueue_thenItSucceed() throws InterruptedException {
+        //given
+        ExecutorService executor = Executors.newFixedThreadPool(2);
+        final SynchronousQueue<Integer> queue = new SynchronousQueue<>();
+
+        Runnable producer = () -> {
+            Integer producedElement = ThreadLocalRandom.current().nextInt();
+            try {
+                System.out.println("Saving an element: " + producedElement + " to the exchange point");
+                queue.put(producedElement);
+            } catch (InterruptedException ex) {
+                ex.printStackTrace();
+            }
+        };
+
+        Runnable consumer = () -> {
+            try {
+                Integer consumedElement = queue.take();
+                System.out.println("consumed an element: " + consumedElement + " from the exchange point");
+            } catch (InterruptedException ex) {
+                ex.printStackTrace();
+            }
+        };
+
+        //when
+        executor.execute(producer);
+        executor.execute(consumer);
+
+        //then
+        executor.awaitTermination(500, TimeUnit.MILLISECONDS);
+        executor.shutdown();
+        assertEquals(queue.size(), 0);
+    }
+}

core-java/src/test/java/com/baeldung/transferqueue/TransferQueueTest.java

@@ -0,0 +1,74 @@
+package com.baeldung.transferqueue;
+
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.junit.runners.MethodSorters;
+
+import java.util.concurrent.*;
+
+import static junit.framework.TestCase.assertEquals;
+
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class TransferQueueTest {
+
+    @Test
+    public void givenTransferQueue_whenUseMultipleConsumersAndMultipleProducers_thenShouldProcessAllMessages() throws InterruptedException {
+        //given
+        TransferQueue<String> transferQueue = new LinkedTransferQueue<>();
+        ExecutorService exService = Executors.newFixedThreadPool(3);
+        Producer producer1 = new Producer(transferQueue, "1", 3);
+        Producer producer2 = new Producer(transferQueue, "2", 3);
+        Consumer consumer1 = new Consumer(transferQueue, "1", 3);
+        Consumer consumer2 = new Consumer(transferQueue, "2", 3);
+
+        //when
+        exService.execute(producer1);
+        exService.execute(producer2);
+        exService.execute(consumer1);
+        exService.execute(consumer2);
+
+        //then
+        exService.awaitTermination(10_000, TimeUnit.MILLISECONDS);
+        exService.shutdown();
+
+        assertEquals(producer1.numberOfProducedMessages.intValue(), 3);
+        assertEquals(producer2.numberOfProducedMessages.intValue(), 3);
+    }
+
+    @Test
+    public void givenTransferQueue_whenUseOneConsumerAndOneProducer_thenShouldProcessAllMessages() throws InterruptedException {
+        //given
+        TransferQueue<String> transferQueue = new LinkedTransferQueue<>();
+        ExecutorService exService = Executors.newFixedThreadPool(2);
+        Producer producer = new Producer(transferQueue, "1", 3);
+        Consumer consumer = new Consumer(transferQueue, "1", 3);
+
+        //when
+        exService.execute(producer);
+        exService.execute(consumer);
+
+        //then
+        exService.awaitTermination(5000, TimeUnit.MILLISECONDS);
+        exService.shutdown();
+
+        assertEquals(producer.numberOfProducedMessages.intValue(), 3);
+        assertEquals(consumer.numberOfConsumedMessages.intValue(), 3);
+    }
+
+    @Test
+    public void givenTransferQueue_whenUseOneProducerAndNoConsumers_thenShouldFailWithTimeout() throws InterruptedException {
+        //given
+        TransferQueue<String> transferQueue = new LinkedTransferQueue<>();
+        ExecutorService exService = Executors.newFixedThreadPool(2);
+        Producer producer = new Producer(transferQueue, "1", 3);
+
+        //when
+        exService.execute(producer);
+
+        //then
+        exService.awaitTermination(5000, TimeUnit.MILLISECONDS);
+        exService.shutdown();
+
+        assertEquals(producer.numberOfProducedMessages.intValue(), 0);
+    }
+}

core-java/src/test/java/org/baeldung/core/exceptions/FileNotFoundExceptionUnitTest.java

@@ -6,12 +6,14 @@ import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import org.junit.Test;
 
 public class FileNotFoundExceptionUnitTest {
 
-    private static final Logger LOG = Logger.getLogger(FileNotFoundExceptionUnitTest.class);
+    private static final Logger LOG = LoggerFactory.getLogger(FileNotFoundExceptionUnitTest.class);
 
     private String fileName = Double.toString(Math.random());
 

couchbase-sdk/pom.xml

@@ -22,11 +22,23 @@
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
             <version>${spring-framework.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>            
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context-support</artifactId>
             <version>${spring-framework.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
         </dependency>
 
         <!-- Logging with SLF4J & LogBack -->
@@ -46,11 +58,6 @@
             <artifactId>jcl-over-slf4j</artifactId>
             <version>${org.slf4j.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
 
         <!-- Test-Scoped Dependencies -->
         <dependency>

cucumber/README.md

@@ -0,0 +1,3 @@
+### Relevant articles
+
+- [Cucumber and Scenario Outline](http://www.baeldung.com/cucumber-scenario-outline)

deltaspike/pom.xml

@@ -201,12 +201,6 @@
             <artifactId>querydsl-jpa</artifactId>
             <version>${querydsl.version}</version>
         </dependency>
-
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-log4j12</artifactId>
-            <version>${slf4j.version}</version>
-        </dependency>
     </dependencies>
 
     <build>

disruptor/pom.xml

@@ -40,11 +40,6 @@
             <artifactId>jcl-over-slf4j</artifactId>
             <version>${org.slf4j.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
 
         <!-- test scoped -->
 

feign/pom.xml

@@ -18,7 +18,6 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <feign.version>9.4.0</feign.version>
         <slf4j.version>1.7.21</slf4j.version>
-        <log4j.version>2.7</log4j.version>
         <lombok.version>1.16.12</lombok.version>
         <junit.version>4.12</junit.version>
         <maven-compiler-plugin.version>3.6.0</maven-compiler-plugin.version>
@@ -52,16 +51,6 @@
             <artifactId>slf4j-api</artifactId>
             <version>${slf4j.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-core</artifactId>
-            <version>${log4j.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-slf4j-impl</artifactId>
-            <version>${log4j.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>

feign/src/main/resources/log4j2.xml

@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<Configuration status="WARN">
-    <Appenders>
-        <Console name="Console" target="SYSTEM_OUT">
-            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36}:%n[+] %msg%n"/>
-        </Console>
-    </Appenders>
-
-    <Loggers>
-        <Root level="debug">
-            <AppenderRef ref="Console"/>
-        </Root>
-    </Loggers>
-</Configuration>