Merge branch 'master' of https://github.com/eugenp/tutorials into story/BAEL-7636

apache-avro/src/main/java/com/baeldung/avro/util/serealization/AvroDeSerealizer.java

@@ -5,29 +5,37 @@ import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.Decoder;
 import org.apache.avro.io.DecoderFactory;
 import org.apache.avro.specific.SpecificDatumReader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 
 public class AvroDeSerealizer {
 
-public AvroHttpRequest deSerealizeAvroHttpRequestJSON(byte[] data){
-    DatumReader<AvroHttpRequest> reader = new SpecificDatumReader<>(AvroHttpRequest.class);
-    Decoder decoder = null;
-    try {
-        decoder = DecoderFactory.get().jsonDecoder(AvroHttpRequest.getClassSchema(), new String(data));
-        return reader.read(null, decoder);
-    } catch (IOException e) {
-        return null;
-    }
-}
+    private static Logger logger = LoggerFactory.getLogger(AvroDeSerealizer.class);
 
-public AvroHttpRequest deSerealizeAvroHttpRequestBinary(byte[] data){
-    DatumReader<AvroHttpRequest> employeeReader = new SpecificDatumReader<>(AvroHttpRequest.class);
-    Decoder decoder = DecoderFactory.get().binaryDecoder(data, null);
-    try {
-        return employeeReader.read(null, decoder);
-    } catch (IOException e) {
+    public AvroHttpRequest deSerealizeAvroHttpRequestJSON(byte[] data) {
+        DatumReader<AvroHttpRequest> reader = new SpecificDatumReader<>(AvroHttpRequest.class);
+        Decoder decoder = null;
+        try {
+            decoder = DecoderFactory.get()
+                .jsonDecoder(AvroHttpRequest.getClassSchema(), new String(data));
+            return reader.read(null, decoder);
+        } catch (IOException e) {
+            logger.error("Deserialization error" + e.getMessage());
+        }
+        return null;
+    }
+
+    public AvroHttpRequest deSerealizeAvroHttpRequestBinary(byte[] data) {
+        DatumReader<AvroHttpRequest> employeeReader = new SpecificDatumReader<>(AvroHttpRequest.class);
+        Decoder decoder = DecoderFactory.get()
+            .binaryDecoder(data, null);
+        try {
+            return employeeReader.read(null, decoder);
+        } catch (IOException e) {
+            logger.error("Deserialization error" + e.getMessage());
+        }
         return null;
     }
 }
-}

apache-avro/src/main/java/com/baeldung/avro/util/serealization/AvroSerealizer.java

@@ -3,42 +3,48 @@ package com.baeldung.avro.util.serealization;
 import com.baeldung.avro.util.model.AvroHttpRequest;
 import org.apache.avro.io.*;
 import org.apache.avro.specific.SpecificDatumWriter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 public class AvroSerealizer {
 
-public byte[] serealizeAvroHttpRequestJSON(AvroHttpRequest request){
-    DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
-    byte[] data = new byte[0];
-    ByteArrayOutputStream stream = new ByteArrayOutputStream();
-    Encoder jsonEncoder = null;
-    try {
-        jsonEncoder = EncoderFactory.get().jsonEncoder(AvroHttpRequest.getClassSchema(), stream);
-        writer.write(request, jsonEncoder);
-        jsonEncoder.flush();
-        data = stream.toByteArray();
-    } catch (IOException e) {
-        data =null;
-    }
-    return data;
-}
+    private static final Logger logger = LoggerFactory.getLogger(AvroSerealizer.class);
 
-public byte[] serealizeAvroHttpRequestBinary(AvroHttpRequest request){
-    DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
-    byte[] data = new byte[0];
-    ByteArrayOutputStream stream = new ByteArrayOutputStream();
-    Encoder jsonEncoder = EncoderFactory.get().binaryEncoder(stream,null);
-    try {
-        writer.write(request, jsonEncoder);
-        jsonEncoder.flush();
-        data = stream.toByteArray();
-    } catch (IOException e) {
-        data = null;
+    public byte[] serealizeAvroHttpRequestJSON(AvroHttpRequest request) {
+        DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
+        byte[] data = new byte[0];
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        Encoder jsonEncoder = null;
+        try {
+            jsonEncoder = EncoderFactory.get()
+                .jsonEncoder(AvroHttpRequest.getClassSchema(), stream);
+            writer.write(request, jsonEncoder);
+            jsonEncoder.flush();
+            data = stream.toByteArray();
+        } catch (IOException e) {
+            logger.error("Serialization error " + e.getMessage());
+        }
+        return data;
     }
 
-    return data;
-}
+    public byte[] serealizeAvroHttpRequestBinary(AvroHttpRequest request) {
+        DatumWriter<AvroHttpRequest> writer = new SpecificDatumWriter<>(AvroHttpRequest.class);
+        byte[] data = new byte[0];
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        Encoder jsonEncoder = EncoderFactory.get()
+            .binaryEncoder(stream, null);
+        try {
+            writer.write(request, jsonEncoder);
+            jsonEncoder.flush();
+            data = stream.toByteArray();
+        } catch (IOException e) {
+            logger.error("Serialization error " + e.getMessage());
+        }
+
+        return data;
+    }
 
 }

apache-avro/src/test/java/com/baeldung/avro/util/serealization/AvroSerealizerDeSerealizerTest.java

@@ -24,8 +24,10 @@ public class AvroSerealizerDeSerealizerTest {
         serealizer = new AvroSerealizer();
         deSerealizer = new AvroDeSerealizer();
 
-        ClientIdentifier clientIdentifier = ClientIdentifier.newBuilder().
-                setHostName("localhost").setIpAddress("255.255.255.0").build();
+        ClientIdentifier clientIdentifier = ClientIdentifier.newBuilder()
+            .setHostName("localhost")
+            .setIpAddress("255.255.255.0")
+            .build();
 
         List<CharSequence> employees = new ArrayList();
         employees.add("James");
@@ -33,43 +35,49 @@ public class AvroSerealizerDeSerealizerTest {
         employees.add("David");
         employees.add("Han");
 
-        request = AvroHttpRequest.newBuilder().setRequestTime(01l)
-                .setActive(Active.YES).setClientIdentifier(clientIdentifier)
-                .setEmployeeNames(employees).build();
+        request = AvroHttpRequest.newBuilder()
+            .setRequestTime(01l)
+            .setActive(Active.YES)
+            .setClientIdentifier(clientIdentifier)
+            .setEmployeeNames(employees)
+            .build();
     }
 
     @After
     public void tearDown() throws Exception {
     }
 
-@Test
-public void WhenSerialized_UsingJSONEncoder_ObjectGetsSerialized(){
-    byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
-    assertTrue(Objects.nonNull(data));
-    assertTrue(data.length > 0);
-}
+    @Test
+    public void WhenSerializedUsingJSONEncoder_thenObjectGetsSerialized() {
+        byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
+        assertTrue(Objects.nonNull(data));
+        assertTrue(data.length > 0);
+    }
 
-@Test
-public void WhenSerialized_UsingBinaryEncoder_ObjectGetsSerialized(){
-    byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
-    assertTrue(Objects.nonNull(data));
-    assertTrue(data.length > 0);
-}
+    @Test
+    public void WhenSerializedUsingBinaryEncoder_thenObjectGetsSerialized() {
+        byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
+        assertTrue(Objects.nonNull(data));
+        assertTrue(data.length > 0);
+    }
 
-@Test
-public void WhenDeserialize_UsingJSONDecoder_ActualAndExpectedObjectsAreEqual(){
-    byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
-    AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestJSON(data);
-    assertEquals(actualRequest,request);
-    assertTrue(actualRequest.getRequestTime().equals(request.getRequestTime()));
-}
+    @Test
+    public void WhenDeserializeUsingJSONDecoder_thenActualAndExpectedObjectsAreEqual() {
+        byte[] data = serealizer.serealizeAvroHttpRequestJSON(request);
+        AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestJSON(data);
+        assertEquals(actualRequest, request);
+        assertTrue(actualRequest.getRequestTime()
+            .equals(request.getRequestTime()));
+    }
 
-@Test
-public void WhenDeserialize_UsingBinaryecoder_ActualAndExpectedObjectsAreEqual(){
-    byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
-    AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestBinary(data);
-    assertEquals(actualRequest,request);
-    assertTrue(actualRequest.getRequestTime().equals(request.getRequestTime()));
-}
+    @Test
+    public void WhenDeserializeUsingBinaryecoder_thenActualAndExpectedObjectsAreEqual() {
+        byte[] data = serealizer.serealizeAvroHttpRequestBinary(request);
+        AvroHttpRequest actualRequest = deSerealizer.deSerealizeAvroHttpRequestBinary(data);
+        assertEquals(actualRequest, request);
+        assertTrue(actualRequest.getRequestTime()
+            .equals(request.getRequestTime()));
+    }
+    
 }
 

aws/pom.xml

@@ -137,7 +137,7 @@
         <aws-lambda-java-core.version>1.1.0</aws-lambda-java-core.version>
         <gson.version>2.8.0</gson.version>
         <aws-java-sdk.version>1.11.290</aws-java-sdk.version>
-        <mockito-core.version>2.8.9</mockito-core.version>
+        <mockito-core.version>2.21.0</mockito-core.version>
         <assertj-core.version>3.8.0</assertj-core.version>
         <dynamodblocal.version>1.11.86</dynamodblocal.version>
         <dynamodblocal.repository.url>https://s3-us-west-2.amazonaws.com/dynamodb-local/release</dynamodblocal.repository.url>

core-java-8/README.md

@@ -14,7 +14,6 @@
 - [Guide to Java 8 groupingBy Collector](http://www.baeldung.com/java-groupingby-collector)
 - [Strategy Design Pattern in Java 8](http://www.baeldung.com/java-strategy-pattern)
 - [Java 8 and Infinite Streams](http://www.baeldung.com/java-inifinite-streams)
-- [String Operations with Java Streams](http://www.baeldung.com/java-stream-operations-on-strings)
 - [Exceptions in Java 8 Lambda Expressions](http://www.baeldung.com/java-lambda-exceptions)
 - [Java 8 Stream findFirst() vs. findAny()](http://www.baeldung.com/java-stream-findfirst-vs-findany)
 - [Guide to Java 8 Comparator.comparing()](http://www.baeldung.com/java-8-comparator-comparing)
@@ -34,13 +33,11 @@
 - [Copy a File with Java](http://www.baeldung.com/java-copy-file)
 - [Static and Default Methods in Interfaces in Java](http://www.baeldung.com/java-static-default-methods)
 - [Iterable to Stream in Java](http://www.baeldung.com/java-iterable-to-stream)
-- [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
 - [How to Iterate Over a Stream With Indices](http://www.baeldung.com/java-stream-indices)
 - [Efficient Word Frequency Calculator in Java](http://www.baeldung.com/java-word-frequency)
 - [Primitive Type Streams in Java 8](http://www.baeldung.com/java-8-primitive-streams)
 - [Fail-Safe Iterator vs Fail-Fast Iterator](http://www.baeldung.com/java-fail-safe-vs-fail-fast-iterator)
 - [Shuffling Collections In Java](http://www.baeldung.com/java-shuffle-collection)
-- [Java 8 StringJoiner](http://www.baeldung.com/java-string-joiner)
 - [Introduction to Spliterator in Java](http://www.baeldung.com/java-spliterator)
 - [Java 8 Math New Methods](http://www.baeldung.com/java-8-math)
 - [Overview of Java Built-in Annotations](http://www.baeldung.com/java-default-annotations)
@@ -54,7 +51,6 @@
 - [Java 8 Unsigned Arithmetic Support](http://www.baeldung.com/java-unsigned-arithmetic)
 - [How to Get the Start and the End of a Day using Java](http://www.baeldung.com/java-day-start-end)
 - [Generalized Target-Type Inference in Java](http://www.baeldung.com/java-generalized-target-type-inference)
-- [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
 - [Calculate Age in Java](http://www.baeldung.com/java-get-age)
 - [Copy a List to Another List in Java](http://www.baeldung.com/java-copy-list-to-another)
 - [Increment Date in Java](http://www.baeldung.com/java-increment-date)

core-java-9/README.md

@@ -17,7 +17,6 @@
 - [Java 9 Reactive Streams](http://www.baeldung.com/java-9-reactive-streams)
 - [How to Get All Dates Between Two Dates?](http://www.baeldung.com/java-between-dates)
 - [Java 9 java.util.Objects Additions](http://www.baeldung.com/java-9-objects-new)
-- [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
 - [Convert Date to LocalDate or LocalDateTime and Back](http://www.baeldung.com/java-date-to-localdate-and-localdatetime)
 - [Java 9 Variable Handles Demistyfied](http://www.baeldung.com/java-variable-handles)
 - [Exploring the New HTTP Client in Java 9](http://www.baeldung.com/java-9-http-client)

core-java-collections/src/test/java/com/baeldung/list/removefirst/RemoveFirstElementUnitTest.java

@@ -4,6 +4,7 @@ import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -48,4 +49,14 @@ public class RemoveFirstElementUnitTest {
         assertThat(linkedList, not(contains("cat")));
     }
 
+    @Test
+    public void givenStringArray_whenRemovingFirstElement_thenArrayIsSmallerAndElementRemoved() {
+        String[] stringArray = {"foo", "bar", "baz"};
+
+        String[] modifiedArray = Arrays.copyOfRange(stringArray, 1, stringArray.length);
+
+        assertThat(modifiedArray.length, is(2));
+        assertThat(modifiedArray[0], is("bar"));
+    }
+
 }

core-java-collections/src/test/java/org/baeldung/java/collections/CollectionsEmpty.java

@@ -0,0 +1,26 @@
+package org.baeldung.java.collections;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import org.junit.Assert;
+import org.junit.Test;
+
+class CollectionsEmpty {
+
+    @Test
+    public void givenArrayList_whenAddingElement_addsNewElement() {
+        ArrayList<String> mutableList = new ArrayList<>();
+        mutableList.add("test");
+
+        Assert.assertEquals(mutableList.size(), 1);
+        Assert.assertEquals(mutableList.get(0), "test");
+    }
+
+    @Test(expected = UnsupportedOperationException.class)
+    public void givenCollectionsEmptyList_whenAddingElement_throwsUnsupportedOperationException() {
+        List<String> immutableList = Collections.emptyList();
+        immutableList.add("test");
+    }
+
+}

core-java-concurrency-collections/.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-collections/README.md

@@ -0,0 +1,15 @@
+=========
+
+## Core Java Concurrency Collections Examples
+
+### Relevant Articles: 
+- [Guide to java.util.concurrent.BlockingQueue](http://www.baeldung.com/java-blocking-queue)
+- [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 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)
+- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)

core-java-concurrency-collections/pom.xml

@@ -0,0 +1,94 @@
+<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-collections</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>core-java-concurrency-collections</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <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>
+        <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-collections</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>
+            
+        </plugins>
+    </build>
+
+    <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-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-collections/src/main/java/com/baeldung/concurrent/blockingqueue/BlockingQueueUsage.java

@@ -10,15 +10,18 @@ public class BlockingQueueUsage {
         int N_CONSUMERS = Runtime.getRuntime().availableProcessors();
         int poisonPill = Integer.MAX_VALUE;
         int poisonPillPerProducer = N_CONSUMERS / N_PRODUCERS;
-
+        int mod = N_CONSUMERS % N_PRODUCERS;
         BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(BOUND);
 
-        for (int i = 0; i < N_PRODUCERS; i++) {
+        for (int i = 1; i < N_PRODUCERS; i++) {
             new Thread(new NumbersProducer(queue, poisonPill, poisonPillPerProducer)).start();
         }
 
         for (int j = 0; j < N_CONSUMERS; j++) {
             new Thread(new NumbersConsumer(queue, poisonPill)).start();
         }
+        
+        new Thread(new NumbersProducer(queue, poisonPill, poisonPillPerProducer+mod)).start();
+
     }
 }

core-java-concurrency-collections/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>