Merge pull request #1 from eugenp/master

Merge

akka-http/pom.xml

@@ -38,8 +38,6 @@
     </dependencies>
 
     <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <akka.http.version>10.0.11</akka.http.version>
         <akka.stream.version>2.5.11</akka.stream.version>
     </properties>

algorithms-miscellaneous-3/pom.xml

@@ -91,8 +91,6 @@
         <commons-collections4.version>4.3</commons-collections4.version>
         <guava.version>28.0-jre</guava.version>
         <retrofit.version>2.6.0</retrofit.version>
-        <jmh-core.version>1.19</jmh-core.version>
-        <jmh-generator.version>1.19</jmh-generator.version>
         <commons.lang3.version>3.8.1</commons.lang3.version>
         <JUnitParams.version>1.1.0</JUnitParams.version>
     </properties>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithm.java

@@ -13,22 +13,22 @@ public class KadaneAlgorithm {
         int start = 0;
         int end = 0;
 
-        int maxSoFar = 0, maxEndingHere = 0;
-
+        int maxSoFar = arr[0], maxEndingHere = arr[0];
         for (int i = 0; i < size; i++) {
 
             if (arr[i] > maxEndingHere + arr[i]) {
                 start = i;
                 maxEndingHere = arr[i];
-            } else
+            } else {
                 maxEndingHere = maxEndingHere + arr[i];
+            }
 
             if (maxSoFar < maxEndingHere) {
                 maxSoFar = maxEndingHere;
                 end = i;
             }
         }
-        logger.info("Found Maximum Subarray between {} and {}", start, end);
+        logger.info("Found Maximum Subarray between {} and {}", Math.min(start, end), end);
         return maxSoFar;
     }
 }

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithmUnitTest.java

@@ -9,11 +9,22 @@ class KadaneAlgorithmUnitTest {
     @Test
     void givenArrayWithNegativeNumberWhenMaximumSubarrayThenReturns6() {
         //given
-        int[] arr = new int[]{-3, 1, -8, 4, -1, 2, 1, -5, 5};
+        int[] arr = new int[] { -3, 1, -8, 4, -1, 2, 1, -5, 5 };
         //when
         KadaneAlgorithm algorithm = new KadaneAlgorithm();
         int maxSum = algorithm.maxSubArraySum(arr);
         //then
         assertEquals(6, maxSum);
     }
+
+    @Test
+    void givenArrayWithAllNegativeNumbersWhenMaximumSubarrayThenReturnsExpectedResult() {
+        //given
+        int[] arr = new int[] { -8, -7, -5, -4, -3, -1, -2 };
+        //when
+        KadaneAlgorithm algorithm = new KadaneAlgorithm();
+        int maxSum = algorithm.maxSubArraySum(arr);
+        //then
+        assertEquals(-1, maxSum);
+    }
 }

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

@@ -13,7 +13,7 @@ import java.util.Objects;
 
 import static org.junit.Assert.*;
 
-public class AvroSerealizerDeSerealizerUnitTest {
+public class AvroSerealizerDeSerealizerIntegrationTest {
 
     AvroSerealizer serealizer;
     AvroDeSerealizer deSerealizer;

apache-libraries/src/test/java/com/baeldung/meecrowave/ArticleEndpointsIntegrationTest.java

@@ -17,7 +17,7 @@ import okhttp3.Request;
 import okhttp3.Response;
 
 @RunWith(MonoMeecrowave.Runner.class)
-public class ArticleEndpointsUnitTest {
+public class ArticleEndpointsIntegrationTest {
     
     @ConfigurationInject
     private Meecrowave.Builder config;

apache-poi/README.md

@@ -11,3 +11,4 @@ This module contains articles about Apache POI
 - [Get String Value of Excel Cell with Apache POI](https://www.baeldung.com/java-apache-poi-cell-string-value)
 - [Read Excel Cell Value Rather Than Formula With Apache POI](https://www.baeldung.com/apache-poi-read-cell-value-formula)
 - [Setting Formulas in Excel with Apache POI](https://www.baeldung.com/java-apache-poi-set-formulas)
+- [Insert a Row in Excel Using Apache POI](https://www.baeldung.com/apache-poi-insert-excel-row)

aws-reactive/pom.xml

@@ -100,7 +100,6 @@
     </build>
 
     <properties>
-        <java.version>1.8</java.version>
         <spring.version>2.2.1.RELEASE</spring.version>
         <awssdk.version>2.10.27</awssdk.version>
     </properties>

core-groovy-2/pom.xml

@@ -115,7 +115,6 @@
             </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>${surefire.plugin.version}</version>
                 <configuration>
                     <useFile>false</useFile>
                     <includes>
@@ -186,7 +185,6 @@
         <logback.version>1.2.3</logback.version>
         <groovy.version>2.5.7</groovy.version>
         <assembly.plugin.version>3.1.0</assembly.plugin.version>
-        <surefire.plugin.version>2.20.1</surefire.plugin.version>
         <compiler.plugin.version>3.8.0</compiler.plugin.version>
         <groovy.compiler.version>3.3.0-01</groovy.compiler.version>
     </properties>

core-groovy-collections/pom.xml

@@ -101,7 +101,6 @@
             </plugin>
             <plugin>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>${surefire.plugin.version}</version>
                 <configuration>
                     <useFile>false</useFile>
                     <includes>
@@ -128,7 +127,6 @@
         <hsqldb.version>2.4.0</hsqldb.version>
         <spock-core.version>1.1-groovy-2.4</spock-core.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
-        <surefire.plugin.version>2.20.1</surefire.plugin.version>
     </properties>
 
 </project>

core-java-modules/core-java-10/README.md

@@ -11,3 +11,4 @@ This module contains articles about Java 10 core features
 - [Copying Sets in Java](https://www.baeldung.com/java-copy-sets)
 - [Converting between a List and a Set in Java](https://www.baeldung.com/convert-list-to-set-and-set-to-list)
 - [Java IndexOutOfBoundsException “Source Does Not Fit in Dest”](https://www.baeldung.com/java-indexoutofboundsexception)
+- [Collect a Java Stream to an Immutable Collection](https://www.baeldung.com/java-stream-immutable-collection)

core-java-modules/core-java-10/src/test/java/com/baeldung/java10/streams/StreamToImmutableJava10UnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.java10.streams;
+
+import static java.util.stream.Collectors.toUnmodifiableList;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+public class StreamToImmutableJava10UnitTest {
+
+    @Test
+    public void whenUsingCollectorsToUnmodifiableList_thenSuccess() {
+        List<String> givenList = Arrays.asList("a", "b", "c");
+        List<String> result = givenList.stream()
+            .collect(toUnmodifiableList());
+
+        System.out.println(result.getClass());
+    }
+}

core-java-modules/core-java-11/pom.xml

@@ -32,12 +32,12 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
@@ -105,7 +105,6 @@
         <guava.version>27.1-jre</guava.version>
         <assertj.version>3.11.1</assertj.version>
         <uberjar.name>benchmarks</uberjar.name>
-        <jmh.version>1.22</jmh.version>
         <eclipse.collections.version>10.0.0</eclipse.collections.version>
         <shade.plugin.version>3.2.4</shade.plugin.version>
     </properties>

core-java-modules/core-java-arrays-guides/pom.xml

@@ -17,16 +17,18 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.19.0</version>
+            <scope>test</scope>
         </dependency>
     </dependencies>
-
-    <properties>
-        <jmh.version>1.19</jmh.version>
-    </properties>
 </project>

core-java-modules/core-java-arrays-guides/src/test/java/com/baeldung/genericarrays/ListToArrayUnitTest.java

@@ -2,7 +2,6 @@ package com.baeldung.genericarrays;
 
 import org.junit.Test;
 
-import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 

core-java-modules/core-java-arrays-guides/src/test/java/com/baeldung/genericarrays/StreamToArrayUnitTest.java

@@ -0,0 +1,77 @@
+package com.baeldung.genericarrays;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.function.IntFunction;
+import java.util.stream.Stream;
+
+import static java.util.Collections.singletonList;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class StreamToArrayUnitTest {
+
+    @Test
+    public void givenAStream_thenCanGetArrayOfObject() {
+        Object[] strings = Stream.of("A", "AAA", "B", "AAB", "C")
+          .filter(string -> string.startsWith("A"))
+          .toArray();
+
+        assertThat(strings).containsExactly("A", "AAA", "AAB");
+        assertThat(strings).isNotInstanceOf(String[].class);
+    }
+
+    @Test
+    public void givenAStream_thenCanGetArrayOfString() {
+        String[] strings = Stream.of("A", "AAA", "B", "AAB", "C")
+          .filter(string -> string.startsWith("A"))
+          .toArray(String[]::new);
+
+        assertThat(strings).containsExactly("A", "AAA", "AAB");
+        assertThat(strings).isInstanceOf(String[].class);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Test
+    public void givenAStream_whenConvertToOptional_thenCanGetArrayOfOptional() {
+        Stream<Optional<String>> stream = Stream.of("A", "AAA", "B", "AAB", "C")
+                .filter(string -> string.startsWith("A"))
+                .map(Optional::of);
+        Optional<String>[] strings = stream
+          .toArray(Optional[]::new);
+
+        assertThat(strings).containsExactly(Optional.of("A"),
+          Optional.of("AAA"),
+          Optional.of("AAB"));
+        assertThat(strings).isInstanceOf(Optional[].class);
+    }
+
+    @Test
+    public void givenAStream_whenConvertToOptional_thenCanGetArrayOfOptionalWithHelper() {
+        Optional<String>[] strings = Stream.of("A", "AAA", "B", "AAB", "C")
+          .filter(string -> string.startsWith("A"))
+          .map(Optional::of)
+          .toArray(genericArray(Optional[]::new));
+
+        assertThat(strings).containsExactly(Optional.of("A"),
+          Optional.of("AAA"),
+          Optional.of("AAB"));
+        assertThat(strings).isInstanceOf(Optional[].class);
+    }
+
+    @Test
+    public void whenInvalidUseOfGenericArray_thenIllegalCast() {
+        assertThatThrownBy(() -> {
+            ArrayList<String>[] lists = Stream.of(singletonList("A"))
+                    .toArray(genericArray(List[]::new));
+        }).isInstanceOf(ClassCastException.class);
+    }
+
+    @SuppressWarnings("unchecked")
+    private static <T, R extends T> IntFunction<R[]> genericArray(IntFunction<T[]> arrayCreator) {
+        return size -> (R[])arrayCreator.apply(size);
+    }
+}

core-java-modules/core-java-arrays-operations-basic/pom.xml

@@ -24,12 +24,12 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
 
         <dependency>
@@ -68,7 +68,6 @@
 
     <properties>
         <shade.plugin.version>3.2.0</shade.plugin.version>
-        <jmh.version>1.19</jmh.version>
         <assertj-core.version>3.10.0</assertj-core.version>
     </properties>
 </project>

core-java-modules/core-java-arrays-sorting/pom.xml

@@ -31,12 +31,12 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
 
         <!-- Testing -->
@@ -77,7 +77,6 @@
     <properties>
         <shade.plugin.version>3.2.0</shade.plugin.version>
         <guava.version>28.2-jre</guava.version>
-        <jmh.version>1.19</jmh.version>
         <assertj-core.version>3.10.0</assertj-core.version>
     </properties>
 </project>

core-java-modules/core-java-char/pom.xml

@@ -25,17 +25,16 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${openjdk.jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${openjdk.jmh.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
     </dependencies>
 
     <properties>
-        <openjdk.jmh.version>1.19</openjdk.jmh.version>
         <assertj.version>3.11.1</assertj.version>
     </properties>
 

core-java-modules/core-java-collections-3/pom.xml

@@ -24,7 +24,7 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${openjdk.jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
@@ -40,7 +40,6 @@
     </dependencies>
 
     <properties>
-        <openjdk.jmh.version>1.19</openjdk.jmh.version>
         <assertj.version>3.11.1</assertj.version>
         <jol-core.version>0.10</jol-core.version>
     </properties>

core-java-modules/core-java-collections-4/README.md

@@ -5,3 +5,4 @@
 ### Relevant Articles: 
 
 - [ArrayList vs. LinkedList vs. HashMap in Java](https://www.baeldung.com/java-arraylist-vs-linkedlist-vs-hashmap)
+- [Java Deque vs. Stack](https://www.baeldung.com/java-deque-vs-stack)

core-java-modules/core-java-collections-list-3/pom.xml

@@ -58,7 +58,7 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh-core.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
     </dependencies>
 

core-java-modules/core-java-collections-list-3/src/main/java/com/baeldung/list/primitive/PrimitivesListPerformance.java

@@ -8,6 +8,7 @@ import org.openjdk.jmh.runner.options.Options;
 import org.openjdk.jmh.runner.options.OptionsBuilder;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
@@ -18,12 +19,12 @@ import java.util.concurrent.TimeUnit;
 @State(Scope.Thread)
 public class PrimitivesListPerformance {
 
-    private List<Integer> arrayList = new ArrayList<>();
-    private TIntArrayList tList = new TIntArrayList();
-    private cern.colt.list.IntArrayList coltList = new cern.colt.list.IntArrayList();
-    private IntArrayList fastUtilList = new IntArrayList();
+    private List<Integer> arrayList = new ArrayList<>(Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
+    private TIntArrayList tList = new TIntArrayList(new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
+    private cern.colt.list.IntArrayList coltList = new cern.colt.list.IntArrayList(new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
+    private IntArrayList fastUtilList = new IntArrayList(new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
 
-    private int getValue = 10;
+    private int getValue = 4;
 
     @Benchmark
     public boolean addArrayList() {

core-java-modules/core-java-collections-maps-3/README.md

@@ -8,4 +8,5 @@ This module contains articles about Map data structures in Java.
 - [The Map.computeIfAbsent() Method](https://www.baeldung.com/java-map-computeifabsent)
 - [Collections.synchronizedMap vs. ConcurrentHashMap](https://www.baeldung.com/java-synchronizedmap-vs-concurrenthashmap)
 - [Java HashMap Load Factor](https://www.baeldung.com/java-hashmap-load-factor)
+- [Converting java.util.Properties to HashMap](https://www.baeldung.com/java-convert-properties-to-hashmap)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-maps-2)

core-java-modules/core-java-collections/pom.xml

@@ -25,17 +25,16 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${openjdk.jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${openjdk.jmh.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
     </dependencies>
 
     <properties>
-        <openjdk.jmh.version>1.19</openjdk.jmh.version>
         <assertj.version>3.11.1</assertj.version>
     </properties>
 

core-java-modules/core-java-concurrency-advanced-2/pom.xml

@@ -29,7 +29,7 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh-generator-annprocess.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
 
         <dependency>
@@ -51,8 +51,6 @@
     </build>
 
     <properties>
-        <jmh-core.version>1.19</jmh-core.version>
-        <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
         <assertj.version>3.6.1</assertj.version>
     </properties>
 

core-java-modules/core-java-concurrency-collections-2/pom.xml

@@ -23,12 +23,12 @@
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-core.version}</version>
         </dependency>
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
             <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
+            <version>${jmh-generator.version}</version>
         </dependency>
 		<dependency>
             <groupId>org.assertj</groupId>
@@ -39,7 +39,6 @@
     </dependencies>
 
     <properties>
-        <jmh.version>1.21</jmh.version>
         <guava.version>28.2-jre</guava.version>
          <!-- testing -->
         <assertj.version>3.6.1</assertj.version>

core-java-modules/core-java-concurrency-collections/src/test/java/com/baeldung/java/stream/ThreadPoolInParallelStreamIntegrationTest.java

@@ -21,14 +21,16 @@ public class ThreadPoolInParallelStreamIntegrationTest {
         long lastNum = 1_000_000;
 
         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();
 
-        assertEquals((lastNum + firstNum) * lastNum / 2, actualTotal);
+        try {
+            long actualTotal = customThreadPool
+              .submit(() -> aList.parallelStream().reduce(0L, Long::sum))
+              .get();
+            assertEquals((lastNum + firstNum) * lastNum / 2, actualTotal);
+        } finally {
+            customThreadPool.shutdown();
+        }
     }
 
     @Test

core-java-modules/core-java-io-conversions/src/test/java/com/baeldung/filetoinputstream/JavaXToInputStreamUnitTest.java

@@ -5,12 +5,12 @@ import com.google.common.io.CharSource;
 import com.google.common.io.Files;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
-import org.apache.commons.io.input.ReaderInputStream;
 import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.*;
+import java.nio.charset.StandardCharsets;
 
 public class JavaXToInputStreamUnitTest {
     protected final Logger logger = LoggerFactory.getLogger(getClass());
@@ -28,7 +28,7 @@ public class JavaXToInputStreamUnitTest {
     @Test
     public final void givenUsingGuava_whenConvertingStringToInputStream_thenCorrect() throws IOException {
         final String initialString = "text";
-        final InputStream targetStream = new ReaderInputStream(CharSource.wrap(initialString).openStream());
+        final InputStream targetStream = CharSource.wrap(initialString).asByteSource(StandardCharsets.UTF_8).openStream();
 
         IOUtils.closeQuietly(targetStream);
     }

core-java-modules/core-java-jvm/pom.xml

@@ -77,7 +77,6 @@
         <assertj.version>3.6.1</assertj.version>
         <!-- instrumentation -->
         <javaassist.version>3.27.0-GA</javaassist.version>
-        <esapi.version>2.1.0.1</esapi.version>
         <sun.tools.version>1.8.0</sun.tools.version>
         <jol-core.version>0.10</jol-core.version>
         <asm.version>8.0.1</asm.version>