Merge branch 'eugenp:master' into string_to_int_encapsulation

.gitignore

@@ -69,6 +69,7 @@ jmeter/src/main/resources/*-Basic*.csv
 jmeter/src/main/resources/*-JMeter*.csv
 jmeter/src/main/resources/*ReportsDashboard*.csv
 jmeter/src/main/resources/dashboard/*ReportsDashboard*.csv
+jmeter/src/main/resources/*FileExtractionExample.csv
 
 ninja/devDb.mv.db
 
@@ -88,6 +89,7 @@ spring-soap/src/main/java/com/baeldung/springsoap/gen/
 /report-*.json
 transaction.log
 *-shell.log
+customers.xml
 
 apache-cxf/cxf-aegis/baeldung.xml
 testing-modules/report-*.json
@@ -102,6 +104,7 @@ spring-boot-modules/spring-boot-react/frontend/build
 spring-boot-modules/spring-boot-react/frontend/node
 spring-boot-modules/spring-boot-react/frontend/yarn.lock
 spring-boot-modules/spring-boot-properties-3/*.log
+spring-boot-modules/spring-boot-properties-3/*.gz
 
 # SDKMan
 .sdkmanrc
@@ -114,4 +117,7 @@ libraries-2/employee*
 libraries-2/src/test/resources/crawler4j/**
 
 #web-modules/ninja
-devDb*.db
+devDb*.db
+
+#jaxb
+*.xjb

akka-modules/akka-http/pom.xml

@@ -36,7 +36,6 @@
         </dependency>
     </dependencies>
 
-
     <properties>
         <akka.http.version>10.0.11</akka.http.version>
         <akka.stream.version>2.5.11</akka.stream.version>

algorithms-modules/algorithms-miscellaneous-7/README.md

@@ -1,4 +1,6 @@
 ### Relevant Articles:
 
 - [Algorithm to Identify and Validate a Credit Card Number](https://www.baeldung.com/java-validate-cc-number)
+- [Find the N Most Frequent Elements in a Java Array](https://www.baeldung.com/java-n-most-frequent-elements-array)
+- [Getting Pixel Array From Image in Java](https://www.baeldung.com/java-getting-pixel-array-from-image)
 - More articles: [[<-- prev]](/algorithms-miscellaneous-6)

algorithms-modules/algorithms-miscellaneous-7/src/main/java/com/baeldung/algorithms/pixelarray/GetPixelArray.java

@@ -0,0 +1,65 @@
+package com.baeldung.algorithms.pixelarray;
+
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBufferByte;
+public class GetPixelArray {
+
+    public static int[][] get2DPixelArraySlow(BufferedImage sampleImage) {
+        int width = sampleImage.getWidth();
+        int height = sampleImage.getHeight();
+        int[][] result = new int[height][width];
+
+        for (int row = 0; row < height; row++) {
+            for (int col = 0; col < width; col++) {
+                result[row][col] = sampleImage.getRGB(col, row);
+            }
+        }
+
+        return result;
+    }
+
+    public static int[][] get2DPixelArrayFast(BufferedImage image) {
+        final byte[] pixelData = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
+        final int width = image.getWidth();
+        final int height = image.getHeight();
+        final boolean hasAlphaChannel = image.getAlphaRaster() != null;
+
+        int[][] result = new int[height][width];
+        if (hasAlphaChannel) {
+            final int numberOfValues = 4;
+            for (int valueIndex = 0, row = 0, col = 0; valueIndex + numberOfValues - 1 < pixelData.length; valueIndex += numberOfValues) {
+                // Getting the values for each pixel from the pixelData array.
+                int argb = 0;
+                argb += (((int) pixelData[valueIndex] & 0xff) << 24); // alpha value
+                argb += ((int) pixelData[valueIndex + 1] & 0xff); // blue value
+                argb += (((int) pixelData[valueIndex + 2] & 0xff) << 8); // green value
+                argb += (((int) pixelData[valueIndex + 3] & 0xff) << 16); // red value
+                result[row][col] = argb;
+
+                col++;
+                if (col == width) {
+                    col = 0;
+                    row++;
+                }
+            }
+        } else {
+            final int numberOfValues = 3;
+            for (int valueIndex = 0, row = 0, col = 0; valueIndex + numberOfValues - 1 < pixelData.length; valueIndex += numberOfValues) {
+                int argb = 0;
+                argb += -16777216; // 255 alpha value (fully opaque)
+                argb += ((int) pixelData[valueIndex] & 0xff); // blue value
+                argb += (((int) pixelData[valueIndex + 1] & 0xff) << 8); // green value
+                argb += (((int) pixelData[valueIndex + 2] & 0xff) << 16); // red value
+                result[row][col] = argb;
+
+                col++;
+                if (col == width) {
+                    col = 0;
+                    row++;
+                }
+            }
+        }
+
+        return result;
+    }
+}

algorithms-modules/algorithms-miscellaneous-7/src/test/java/com/baeldung/algorithms/pixelarray/GetPixelArrayUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.pixelarray;
+
+import static com.baeldung.algorithms.pixelarray.GetPixelArray.get2DPixelArrayFast;
+import static com.baeldung.algorithms.pixelarray.GetPixelArray.get2DPixelArraySlow;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
+
+public class GetPixelArrayUnitTest {
+    @Test
+    public void givenImage_whenGetPixelArray_thenBothMethodsReturnEqualValues() {
+        BufferedImage sampleImage = null;
+        try {
+            sampleImage = ImageIO.read(new File("src/main/resources/images/sampleImage.jpg"));
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+
+        int[][] firstResult = get2DPixelArraySlow(sampleImage);
+        int[][] secondResult = get2DPixelArrayFast(sampleImage);
+
+        assertTrue(Arrays.deepEquals(firstResult, secondResult));
+    }
+}

annotations/annotation-processing/pom.xml

@@ -21,7 +21,6 @@
         </dependency>
     </dependencies>
 
-
     <properties>
         <auto-service.version>1.0-rc2</auto-service.version>
     </properties>

apache-httpclient-2/README.md

@@ -12,6 +12,6 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Reading an HTTP Response Body as a String in Java](https://www.baeldung.com/java-http-response-body-as-string)
 - [How To Get Cookies From the Apache HttpClient Response](https://www.baeldung.com/java-apache-httpclient-cookies)
 - [Enabling Logging for Apache HttpClient](https://www.baeldung.com/apache-httpclient-enable-logging)
-- [Expand Shortened URLs with Apache HttpClient](https://www.baeldung.com/apache-httpclient-expand-url)
 - [Apache HttpClient vs. CloseableHttpClient](https://www.baeldung.com/apache-httpclient-vs-closeablehttpclient)
+- [Expand Shortened URLs with Apache HttpClient](https://www.baeldung.com/apache-httpclient-expand-url)
 - More articles: [[<-- prev]](../apache-httpclient)

apache-httpclient-2/src/test/java/com/baeldung/httpclient/expandUrl/HttpClientExpandUrlLiveTest.java

@@ -0,0 +1,126 @@
+package com.baeldung.httpclient.expandUrl;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+
+import java.io.IOException;
+import java.util.List;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+
+import org.apache.commons.lang3.tuple.ImmutablePair;
+import org.apache.commons.lang3.tuple.Pair;
+
+import org.apache.hc.client5.http.classic.methods.HttpHead;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+
+import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
+import org.apache.hc.core5.http.Header;
+import org.apache.hc.core5.http.HttpHeaders;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class HttpClientExpandUrlLiveTest {
+
+    private static CloseableHttpClient httpClient;
+
+    @BeforeAll
+    static void setup() {
+        httpClient = HttpClientBuilder.create()
+            .disableRedirectHandling()
+            .build();
+    }
+
+    @AfterAll
+    static void tearDown() throws IOException {
+        if (httpClient != null) {
+            httpClient.close();
+        }
+    }
+
+    @Test
+    void givenShortenedOnce_whenUrlIsExpanded_thenCorrectResult() throws IOException {
+        final String expectedResult = "https://www.baeldung.com/rest-versioning";
+        final String actualResult = expandSingleLevel("http://bit.ly/3LScTri");
+        assertThat(actualResult, equalTo(expectedResult));
+    }
+
+    @Test
+    void givenShortenedMultiple_whenUrlIsExpanded_thenCorrectResult() throws IOException {
+        final String expectedResult = "https://www.baeldung.com/rest-versioning";
+        final String actualResult = expand("http://t.co/e4rDDbnzmk");
+        assertThat(actualResult, equalTo(expectedResult));
+    }
+
+    private String expand(final String urlArg) throws IOException {
+        String originalUrl = urlArg;
+        String newUrl = expandSingleLevel(originalUrl);
+        while (!originalUrl.equals(newUrl)) {
+            originalUrl = newUrl;
+            newUrl = expandSingleLevel(originalUrl);
+        }
+
+        return newUrl;
+    }
+
+    final String expandSafe(final String urlArg) throws IOException {
+        String originalUrl = urlArg;
+        String newUrl = expandSingleLevelSafe(originalUrl).getRight();
+        final List<String> alreadyVisited = Lists.newArrayList(originalUrl, newUrl);
+        while (!originalUrl.equals(newUrl)) {
+            originalUrl = newUrl;
+            final Pair<Integer, String> statusAndUrl = expandSingleLevelSafe(originalUrl);
+            newUrl = statusAndUrl.getRight();
+            final boolean isRedirect = statusAndUrl.getLeft() == 301 || statusAndUrl.getLeft() == 302;
+            if (isRedirect && alreadyVisited.contains(newUrl)) {
+                throw new IllegalStateException("Likely a redirect loop");
+            }
+            alreadyVisited.add(newUrl);
+        }
+
+        return newUrl;
+    }
+
+    private Pair<Integer, String> expandSingleLevelSafe(final String url) throws IOException {
+        try {
+            HttpHead request = new HttpHead(url);
+            Pair<Integer, String> resp = httpClient.execute(request, response -> {
+                final int statusCode = response.getCode();
+                if (statusCode != 301 && statusCode != 302) {
+                    return new ImmutablePair<>(statusCode, url);
+                }
+                final Header[] headers = response.getHeaders(HttpHeaders.LOCATION);
+                Preconditions.checkState(headers.length == 1);
+                final String newUrl = headers[0].getValue();
+
+                return new ImmutablePair<>(statusCode, newUrl);
+            });
+            return resp;
+        } catch (final IllegalArgumentException uriEx) {
+            return new ImmutablePair<>(500, url);
+        }
+    }
+
+    private String expandSingleLevel(final String url) throws IOException {
+        try {
+            HttpHead request = new HttpHead(url);
+            String expandedUrl = httpClient.execute(request, response -> {
+                final int statusCode = response.getCode();
+                if (statusCode != 301 && statusCode != 302) {
+                    return url;
+                }
+                final Header[] headers = response.getHeaders(HttpHeaders.LOCATION);
+                Preconditions.checkState(headers.length == 1);
+
+                return headers[0].getValue();
+            });
+            return expandedUrl;
+        } catch (final IllegalArgumentException uriEx) {
+            return url;
+        }
+    }
+
+}

apache-httpclient/src/test/java/com/baeldung/httpclient/HttpClientCancelRequestLiveTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.httpclient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.IOException;
+
+import org.apache.hc.client5.http.classic.methods.HttpGet;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.core5.http.HttpEntity;
+import org.apache.hc.core5.http.HttpStatus;
+import org.junit.jupiter.api.Test;
+
+class HttpClientCancelRequestLiveTest {
+
+    private static final String SAMPLE_URL = "http://www.github.com";
+
+    @Test
+    void whenRequestIsCanceled_thenCorrect() throws IOException {
+        HttpGet request = new HttpGet(SAMPLE_URL);
+        try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+                httpClient.execute(request, response -> {
+                HttpEntity entity = response.getEntity();
+
+                System.out.println("----------------------------------------");
+                System.out.println(response.getCode());
+                if (entity != null) {
+                    System.out.println("Response content length: " + entity.getContentLength());
+                }
+                System.out.println("----------------------------------------");
+                // Do not feel like reading the response body
+                // Call abort on the request object
+                request.abort();
+
+                assertThat(response.getCode()).isEqualTo(HttpStatus.SC_OK);
+                return response;
+            });
+        }
+    }
+}

apache-httpclient/src/test/java/com/baeldung/httpclient/base/HttpClientLiveTest.java

@@ -1,8 +1,8 @@
 package com.baeldung.httpclient.base;
 
 import com.baeldung.httpclient.ResponseUtil;
+
 import org.apache.http.Header;
-import org.apache.http.HttpEntity;
 import org.apache.http.HttpHeaders;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.CloseableHttpResponse;
@@ -10,7 +10,6 @@ import org.apache.http.client.methods.HttpGet;
 import org.apache.http.conn.ConnectTimeoutException;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClientBuilder;
-import org.apache.http.impl.client.HttpClients;
 import org.apache.http.impl.conn.BasicHttpClientConnectionManager;
 import org.junit.After;
 import org.junit.Before;
@@ -73,30 +72,4 @@ public class HttpClientLiveTest {
         assertThat(headers, not(emptyArray()));
     }
 
-    // tests - cancel request
-
-    @Test
-    public final void whenRequestIsCanceled_thenCorrect() throws IOException {
-        instance = HttpClients.custom().build();
-        final HttpGet request = new HttpGet(SAMPLE_URL);
-        response = instance.execute(request);
-
-        try {
-            final HttpEntity entity = response.getEntity();
-
-            System.out.println("----------------------------------------");
-            System.out.println(response.getStatusLine());
-            if (entity != null) {
-                System.out.println("Response content length: " + entity.getContentLength());
-            }
-            System.out.println("----------------------------------------");
-
-            // Do not feel like reading the response body
-            // Call abort on the request object
-            request.abort();
-        } finally {
-            response.close();
-        }
-    }
-
 }

apache-httpclient4/README.md

@@ -4,11 +4,13 @@ This module contains articles about Apache HttpClient 4.5
 
 ### Relevant Articles
 
+- [Apache HttpClient – Cancel Request](https://www.baeldung.com/httpclient-cancel-request)
 - [Apache HttpClient with SSL](https://www.baeldung.com/httpclient-ssl)
 - [Apache HttpClient Timeout](https://www.baeldung.com/httpclient-timeout)
 - [Custom HTTP Header with the Apache HttpClient](https://www.baeldung.com/httpclient-custom-http-header)
 - [Apache HttpClient vs. CloseableHttpClient](https://www.baeldung.com/apache-httpclient-vs-closeablehttpclient)
 - [Expand Shortened URLs with Apache HttpClient](https://www.baeldung.com/apache-httpclient-expand-url)
+- [Retrying Requests using Apache HttpClient](https://www.baeldung.com/java-retrying-requests-using-apache-httpclient)
 
 ### Running the Tests
 To run the live tests, use the command: mvn clean install -Plive

apache-httpclient4/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-httpclient4</artifactId>
     <version>0.1-SNAPSHOT</version>

apache-httpclient4/src/test/java/com/baeldung/httpclient/HttpClientCancelRequestV4LiveTest.java

@@ -0,0 +1,57 @@
+package com.baeldung.httpclient;
+
+import java.io.IOException;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.impl.client.HttpClients;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class HttpClientCancelRequestV4LiveTest {
+
+    private static final String SAMPLE_URL = "http://www.github.com";
+
+    private CloseableHttpClient instance;
+
+    private CloseableHttpResponse response;
+
+    @Before
+    public final void before() {
+        instance = HttpClientBuilder.create().build();
+    }
+
+    @After
+    public final void after() throws IllegalStateException, IOException {
+        ResponseUtil.closeResponse(response);
+    }
+
+    @Test
+    public final void whenRequestIsCanceled_thenCorrect() throws IOException {
+        instance = HttpClients.custom().build();
+        final HttpGet request = new HttpGet(SAMPLE_URL);
+        response = instance.execute(request);
+
+        try {
+            final HttpEntity entity = response.getEntity();
+
+            System.out.println("----------------------------------------");
+            System.out.println(response.getStatusLine());
+            if (entity != null) {
+                System.out.println("Response content length: " + entity.getContentLength());
+            }
+            System.out.println("----------------------------------------");
+
+            // Do not feel like reading the response body
+            // Call abort on the request object
+            request.abort();
+        } finally {
+            response.close();
+        }
+    }
+}

apache-httpclient4/src/test/java/com/baeldung/httpclient/retry/ApacheHttpClientRetryLiveTest.java

@@ -0,0 +1,168 @@
+package com.baeldung.httpclient.retry;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.UnknownHostException;
+import java.util.Objects;
+
+import org.apache.http.HttpRequestInterceptor;
+import org.apache.http.HttpResponseInterceptor;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPatch;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.client.methods.HttpPut;
+import org.apache.http.client.protocol.HttpClientContext;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class ApacheHttpClientRetryLiveTest {
+
+    private Integer requestCounter;
+    private CloseableHttpClient httpClient;
+
+    @BeforeEach
+    void setUp() {
+        requestCounter = 0;
+    }
+
+    @AfterEach
+    void tearDown() throws IOException {
+        if (httpClient != null) {
+            httpClient.close();
+        }
+    }
+
+    private void createDefaultApacheHttpClient() {
+        this.httpClient = HttpClientBuilder
+          .create()
+          .addInterceptorFirst((HttpRequestInterceptor) (httpRequest, httpContext) -> {
+              requestCounter++;
+          }).build();
+    }
+
+    private void createFailingHttpClient() {
+        this.httpClient = HttpClientBuilder
+          .create()
+          .addInterceptorFirst((HttpRequestInterceptor) (httpRequest, httpContext) -> requestCounter++)
+          .addInterceptorLast((HttpResponseInterceptor) (httpResponse, httpContext) -> {
+              throw new IOException();
+          })
+          .build();
+    }
+
+    private void createHttpClientWithRetryHandler() {
+        this.httpClient = HttpClientBuilder
+          .create()
+          .addInterceptorFirst((HttpRequestInterceptor) (httpRequest, httpContext) -> requestCounter++)
+          .addInterceptorLast((HttpResponseInterceptor) (httpRequest, httpContext) -> { throw new IOException(); })
+          .setRetryHandler(new DefaultHttpRequestRetryHandler(6, true))
+          .build();
+    }
+
+    private void createHttpClientWithCustomRetryHandler() {
+        this.httpClient = HttpClientBuilder
+          .create()
+          .addInterceptorFirst((HttpRequestInterceptor) (httpRequest, httpContext) -> requestCounter++)
+          .addInterceptorLast((HttpResponseInterceptor) (httpRequest, httpContext) -> { throw new IOException(); })
+          .setRetryHandler((exception, executionCount, context) -> {
+              if (executionCount < 5 && Objects.equals("GET", ((HttpClientContext) context).getRequest().getRequestLine().getMethod())) {
+                  return true;
+              } else {
+                  return false;
+              }
+          })
+          .build();
+    }
+
+    private void createHttpClientWithRetriesDisabled() {
+        this.httpClient = HttpClientBuilder
+          .create()
+          .addInterceptorFirst((HttpRequestInterceptor) (httpRequest, httpContext) -> requestCounter++)
+          .addInterceptorLast((HttpResponseInterceptor) (httpRequest, httpContext) -> { throw new IOException(); })
+          .disableAutomaticRetries()
+          .build();
+    }
+
+    @Test
+    public void givenDefaultConfiguration_whenReceivedIOException_thenRetriesPerformed() {
+        createFailingHttpClient();
+        assertThrows(IOException.class, () -> httpClient.execute(new HttpGet("https://httpstat.us/200")));
+        assertThat(requestCounter).isEqualTo(4);
+    }
+
+    @Test
+    public void givenDefaultConfiguration_whenDomainNameNotResolved_thenNoRetryApplied() {
+        createDefaultApacheHttpClient();
+        HttpGet request = new HttpGet(URI.create("http://domain.that.does.not.exist:80/api/v1"));
+
+        assertThrows(UnknownHostException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(1);
+    }
+
+    @Test
+    public void givenDefaultConfiguration_whenGotInternalServerError_thenNoRetryLogicApplied() throws IOException {
+        createDefaultApacheHttpClient();
+        HttpGet request = new HttpGet(URI.create("https://httpstat.us/500"));
+
+        CloseableHttpResponse response = assertDoesNotThrow(() -> httpClient.execute(request));
+        assertThat(response.getStatusLine().getStatusCode()).isEqualTo(500);
+        assertThat(requestCounter).isEqualTo(1);
+        response.close();
+    }
+
+    @Test
+    public void givenDefaultConfiguration_whenHttpPatchRequest_thenRetryIsNotApplied() {
+        createFailingHttpClient();
+        HttpPatch request = new HttpPatch(URI.create("https://httpstat.us/500"));
+
+        assertThrows(IOException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(1);
+    }
+
+    @Test
+    public void givenDefaultConfiguration_whenHttpPutRequest_thenRetryIsNotApplied() {
+        createFailingHttpClient();
+        HttpPut request = new HttpPut(URI.create("https://httpstat.us/500"));
+
+        assertThrows(IOException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(1);
+    }
+
+    @Test
+    public void givenConfiguredRetryHandler_whenHttpPostRequest_thenRetriesPerformed() {
+        createHttpClientWithRetryHandler();
+
+        HttpPost request = new HttpPost(URI.create("https://httpstat.us/200"));
+
+        assertThrows(IOException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(7);
+    }
+
+    @Test
+    public void givenCustomRetryHandler_whenUnknownHostException_thenRetryAnyway() {
+        createHttpClientWithCustomRetryHandler();
+
+        HttpGet request = new HttpGet(URI.create("https://domain.that.does.not.exist/200"));
+
+        assertThrows(IOException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(5);
+    }
+
+    @Test
+    public void givenDisabledRetries_whenExecutedHttpRequestEndUpWithIOException_thenRetryIsNotApplied() {
+        createHttpClientWithRetriesDisabled();
+        HttpGet request = new HttpGet(URI.create("https://httpstat.us/200"));
+
+        assertThrows(IOException.class, () -> httpClient.execute(request));
+        assertThat(requestCounter).isEqualTo(1);
+    }
+}

apache-kafka-2/README.md

@@ -7,3 +7,4 @@ You can build the project from the command line using: *mvn clean install*, or i
 
 ### Relevant Articles:
 - [Guide to Check if Apache Kafka Server Is Running](https://www.baeldung.com/apache-kafka-check-server-is-running)
+- [Add Custom Headers to a Kafka Message](https://www.baeldung.com/java-kafka-custom-headers)

apache-kafka-2/src/main/java/com/baeldung/kafka/headers/KafkaMessageHeaders.java

@@ -0,0 +1,88 @@
+package com.baeldung.kafka.headers;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Properties;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.common.header.Header;
+import org.apache.kafka.common.header.Headers;
+import org.apache.kafka.common.header.internals.RecordHeader;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class KafkaMessageHeaders {
+
+    private static Logger logger = LoggerFactory.getLogger(KafkaMessageHeaders.class);
+
+    private static String TOPIC = "baeldung";
+    private static String MESSAGE_KEY = "message";
+    private static String MESSAGE_VALUE = "Hello World";
+    private static String HEADER_KEY = "website";
+    private static String HEADER_VALUE = "baeldung.com";
+
+    private static KafkaProducer<String, String> producer;
+    private static KafkaConsumer<String, String> consumer;
+
+    public static void main(String[] args) {
+        setup();
+
+        publishMessageWithCustomHeaders();
+
+        consumeMessageWithCustomHeaders();
+    }
+
+    private static void consumeMessageWithCustomHeaders() {
+        consumer.subscribe(Arrays.asList(TOPIC));
+
+        ConsumerRecords<String, String> records = consumer.poll(Duration.ofMinutes(1));
+        for (ConsumerRecord<String, String> record : records) {
+            logger.info(record.key());
+            logger.info(record.value());
+
+            Headers headers = record.headers();
+            for (Header header : headers) {
+                logger.info(header.key());
+                logger.info(new String(header.value()));
+            }
+        }
+    }
+
+    private static void publishMessageWithCustomHeaders() {
+        List<Header> headers = new ArrayList<>();
+        headers.add(new RecordHeader(HEADER_KEY, HEADER_VALUE.getBytes()));
+
+        ProducerRecord<String, String> record1 = new ProducerRecord<>(TOPIC, null, MESSAGE_KEY, MESSAGE_VALUE, headers);
+        producer.send(record1);
+
+        ProducerRecord<String, String> record2 = new ProducerRecord<>(TOPIC, null, System.currentTimeMillis(), MESSAGE_KEY, MESSAGE_VALUE, headers);
+        producer.send(record2);
+    }
+
+    private static void setup() {
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "ConsumerGroup1");
+
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+    }
+
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/KafaConsumeLastNMessages.java

@@ -0,0 +1,138 @@
+package com.baeldung.kafka;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.common.TopicPartition;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+@Testcontainers
+public class KafaConsumeLastNMessages {
+
+    private static String TOPIC1 = "baeldung-github";
+    private static String TOPIC2 = "baeldung-blog";
+    private static String MESSAGE_KEY = "message";
+    private static KafkaProducer<String, String> producer;
+    private static KafkaConsumer<String, String> consumer;
+    private static KafkaProducer<String, String> transactionalProducer;
+
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:latest"));
+
+    @BeforeAll
+    static void setup() {
+        KAFKA_CONTAINER.addExposedPort(9092);
+
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "ConsumerGroup1");
+
+        Properties transactionalProducerProprieties = new Properties();
+        transactionalProducerProprieties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        transactionalProducerProprieties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        transactionalProducerProprieties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        transactionalProducerProprieties.put(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG, "true");
+        transactionalProducerProprieties.put(ProducerConfig.TRANSACTIONAL_ID_CONFIG, "prod-0");
+
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+        transactionalProducer = new KafkaProducer<>(transactionalProducerProprieties);
+    }
+
+    @AfterAll
+    static void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void whenSeekingKafkaTopicCursorToEnd_consumerRetrievesOnlyDesiredNumberOfMessages() throws ExecutionException, InterruptedException {
+        int messagesInTopic = 100;
+        int messagesToRetrieve = 20;
+
+        for (int i = 0; i < messagesInTopic; i++) {
+            producer.send(new ProducerRecord<>(TOPIC1, null, MESSAGE_KEY, String.valueOf(i)))
+                    .get();
+        }
+
+        TopicPartition partition = new TopicPartition(TOPIC1, 0);
+        List<TopicPartition> partitions = new ArrayList<>();
+        partitions.add(partition);
+        consumer.assign(partitions);
+
+        consumer.seekToEnd(partitions);
+        long startIndex = consumer.position(partition) - messagesToRetrieve;
+        consumer.seek(partition, startIndex);
+
+        ConsumerRecords<String, String> records = consumer.poll(Duration.ofMinutes(1));
+        int recordsReceived = 0;
+        for (ConsumerRecord<String, String> record : records) {
+            assertEquals(MESSAGE_KEY, record.key());
+            assertTrue(Integer.parseInt(record.value()) >= (messagesInTopic - messagesToRetrieve));
+            recordsReceived++;
+        }
+
+        assertEquals(messagesToRetrieve, recordsReceived);
+    }
+
+    @Test
+    void havingTransactionalProducer_whenSeekingKafkaTopicCursorToEnd_consumerRetrievesLessMessages() throws ExecutionException, InterruptedException {
+        int messagesInTopic = 100;
+        int messagesToRetrieve = 20;
+
+        transactionalProducer.initTransactions();
+        for (int i = 0; i < messagesInTopic; i++) {
+            transactionalProducer.beginTransaction();
+            transactionalProducer.send(new ProducerRecord<>(TOPIC2, null, MESSAGE_KEY, String.valueOf(i)))
+                    .get();
+            transactionalProducer.commitTransaction();
+        }
+
+        TopicPartition partition = new TopicPartition(TOPIC2, 0);
+        List<TopicPartition> partitions = new ArrayList<>();
+        partitions.add(partition);
+        consumer.assign(partitions);
+
+        consumer.seekToEnd(partitions);
+        long startIndex = consumer.position(partition) - messagesToRetrieve;
+        consumer.seek(partition, startIndex);
+
+        ConsumerRecords<String, String> records = consumer.poll(Duration.ofMinutes(1));
+        int recordsReceived = 0;
+        for (ConsumerRecord<String, String> record : records) {
+            assertEquals(MESSAGE_KEY, record.key());
+            assertTrue(Integer.parseInt(record.value()) >= (messagesInTopic - messagesToRetrieve));
+            recordsReceived++;
+        }
+
+        assertTrue(messagesToRetrieve > recordsReceived);
+    }
+
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/headers/KafkaMessageHeadersLiveTest.java

@@ -0,0 +1,104 @@
+package com.baeldung.kafka.headers;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+import org.apache.kafka.clients.consumer.ConsumerRecords;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.apache.kafka.common.header.Header;
+import org.apache.kafka.common.header.Headers;
+import org.apache.kafka.common.header.internals.RecordHeader;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+// This live test needs a Docker Daemon running so that a kafka container can be created
+
+@Testcontainers
+public class KafkaMessageHeadersLiveTest {
+
+    private static String TOPIC = "baeldung";
+    private static String MESSAGE_KEY = "message";
+    private static String MESSAGE_VALUE = "Hello World";
+    private static String HEADER_KEY = "website";
+    private static String HEADER_VALUE = "baeldung.com";
+
+    private static KafkaProducer<String, String> producer;
+    private static KafkaConsumer<String, String> consumer;
+
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:latest"));
+
+    @BeforeAll
+    static void setup() {
+        KAFKA_CONTAINER.addExposedPort(9092);
+
+        Properties producerProperties = new Properties();
+        producerProperties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        producerProperties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerProperties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+
+        Properties consumerProperties = new Properties();
+        consumerProperties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, KAFKA_CONTAINER.getBootstrapServers());
+        consumerProperties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerProperties.put(ConsumerConfig.GROUP_ID_CONFIG, "ConsumerGroup1");
+
+        producer = new KafkaProducer<>(producerProperties);
+        consumer = new KafkaConsumer<>(consumerProperties);
+    }
+
+    @AfterAll
+    static void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void givenAMessageWithCustomHeaders_whenPublishedToKafkaAndConsumed_thenCheckForCustomHeaders() throws ExecutionException, InterruptedException {
+        List<Header> headers = new ArrayList<>();
+        headers.add(new RecordHeader(HEADER_KEY, HEADER_VALUE.getBytes()));
+
+        ProducerRecord<String, String> record1 = new ProducerRecord<>(TOPIC, null, MESSAGE_KEY, MESSAGE_VALUE, headers);
+        Future<RecordMetadata> future = producer.send(record1);
+
+        RecordMetadata metadata = future.get();
+
+        assertNotNull(metadata);
+
+        consumer.subscribe(Arrays.asList(TOPIC));
+
+        ConsumerRecords<String, String> records = consumer.poll(Duration.ofMinutes(1));
+        for (ConsumerRecord<String, String> record : records) {
+            assertEquals(MESSAGE_KEY, record.key());
+            assertEquals(MESSAGE_VALUE, record.value());
+
+            Headers consumedHeaders = record.headers();
+            assertNotNull(consumedHeaders);
+
+            for (Header header : consumedHeaders) {
+                assertEquals(HEADER_KEY, header.key());
+                assertEquals(HEADER_VALUE, new String(header.value()));
+            }
+        }
+    }
+}

apache-kafka/pom.xml

@@ -171,7 +171,8 @@
                 <configuration>
                     <argLine>
                         --add-opens java.base/java.time=ALL-UNNAMED
-                        --add-opens java.base/java.nio=ALL-UNNAMED
+                        --add-opens
+                        java.base/java.nio=ALL-UNNAMED
                         --add-opens java.base/java.util=ALL-UNNAMED
                     </argLine>
                 </configuration>
@@ -179,8 +180,6 @@
         </plugins>
     </build>
 
-
-
     <properties>
         <kafka.version>3.4.0</kafka.version>
         <testcontainers-kafka.version>1.15.3</testcontainers-kafka.version>

apache-libraries/src/test/java/com/baeldung/apache/beam/intro/WordCountIntegrationTest.java

@@ -7,7 +7,7 @@ import org.junit.Test;
 
 import com.baeldung.apache.beam.intro.WordCount;
 
-public class WordCountUnitTest {
+public class WordCountIntegrationTest {
     
     @Test
     public void givenInputFile_whenWordCountRuns_thenJobFinishWithoutError() {

apache-poi/pom.xml

@@ -30,6 +30,16 @@
                 </exclusion>
             </exclusions>
         </dependency>
+        <dependency>
+            <groupId>org.dhatim</groupId>
+            <artifactId>fastexcel</artifactId>
+            <version>${fastexcel.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.dhatim</groupId>
+            <artifactId>fastexcel-reader</artifactId>
+            <version>${fastexcel.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -52,6 +62,7 @@
     <properties>
         <poi.version>5.2.0</poi.version>
         <jexcel.version>1.0.6</jexcel.version>
+        <fastexcel.version>0.15.3</fastexcel.version>
         <maven.resources.plugin.version>3.2.0</maven.resources.plugin.version>
     </properties>
 

apache-poi/src/main/java/com/baeldung/fastexcel/FastexcelHelper.java

@@ -0,0 +1,63 @@
+package com.baeldung.fastexcel;
+
+import org.dhatim.fastexcel.Workbook;
+import org.dhatim.fastexcel.Worksheet;
+import org.dhatim.fastexcel.reader.Cell;
+import org.dhatim.fastexcel.reader.ReadableWorkbook;
+import org.dhatim.fastexcel.reader.Row;
+import org.dhatim.fastexcel.reader.Sheet;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
+public class FastexcelHelper {
+
+    public Map<Integer, List<String>> readExcel(String fileLocation) throws IOException {
+        Map<Integer, List<String>> data = new HashMap<>();
+
+        try (FileInputStream file = new FileInputStream(fileLocation); ReadableWorkbook wb = new ReadableWorkbook(file)) {
+            Sheet sheet = wb.getFirstSheet();
+            try (Stream<Row> rows = sheet.openStream()) {
+                rows.forEach(r -> {
+                    data.put(r.getRowNum(), new ArrayList<>());
+
+                    for (Cell cell : r) {
+                        data.get(r.getRowNum()).add(cell.getRawValue());
+                    }
+                });
+            }
+        }
+
+        return data;
+    }
+
+    public void writeExcel() throws IOException {
+        File currDir = new File(".");
+        String path = currDir.getAbsolutePath();
+        String fileLocation = path.substring(0, path.length() - 1) + "fastexcel.xlsx";
+
+        try (OutputStream os = Files.newOutputStream(Paths.get(fileLocation)); Workbook wb = new Workbook(os, "MyApplication", "1.0")) {
+            Worksheet ws = wb.newWorksheet("Sheet 1");
+
+            ws.width(0, 25);
+            ws.width(1, 15);
+
+            ws.range(0, 0, 0, 1).style().fontName("Arial").fontSize(16).bold().fillColor("3366FF").set();
+            ws.value(0, 0, "Name");
+            ws.value(0, 1, "Age");
+
+            ws.range(2, 0, 2, 1).style().wrapText(true).set();
+            ws.value(2, 0, "John Smith");
+            ws.value(2, 1, 20L);
+        }
+    }
+}

apache-poi/src/test/java/com/baeldung/fastexcel/FastexcelIntegrationTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.fastexcel;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+
+public class FastexcelIntegrationTest {
+
+    private FastexcelHelper fastexcelHelper;
+    private static String FILE_NAME = "fastexcel.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void generateExcelFile() throws IOException {
+
+        File currDir = new File(".");
+        String path = currDir.getAbsolutePath();
+        fileLocation = path.substring(0, path.length() - 1) + FILE_NAME;
+
+        fastexcelHelper = new FastexcelHelper();
+        fastexcelHelper.writeExcel();
+    }
+
+    @Test
+    public void whenParsingExcelFile_thenCorrect() throws IOException {
+        Map<Integer, List<String>> data = fastexcelHelper.readExcel(fileLocation);
+
+        assertEquals("Name", data.get(1).get(0));
+        assertEquals("Age", data.get(1).get(1));
+
+        assertEquals("John Smith", data.get(3).get(0));
+        assertEquals("20", data.get(3).get(1));
+    }
+
+    @After
+    public void cleanup() {
+        File testFile = new File(fileLocation);
+        if (testFile.exists()) {
+            testFile.delete();
+        }
+    }
+}

apache-spark/pom.xml

@@ -7,7 +7,6 @@
     <version>1.0-SNAPSHOT</version>
     <name>apache-spark</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

aws-modules/aws-lambda-modules/lambda-function/pom.xml

@@ -3,14 +3,14 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>lambda</artifactId>
+    <artifactId>lambda-function</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>lambda</name>
+    <name>lambda-function</name>
     <packaging>jar</packaging>
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>aws-lambda</artifactId>
+        <artifactId>aws-lambda-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 

aws-modules/aws-lambda-modules/pom.xml

@@ -3,8 +3,8 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>aws-lambda</artifactId>
-    <name>aws-lambda</name>
+    <artifactId>aws-lambda-modules</artifactId>
+    <name>aws-lambda-modules</name>
     <packaging>pom</packaging>
 
     <parent>
@@ -14,9 +14,9 @@
     </parent>
 
     <modules>
-        <module>lambda</module>
-        <module>shipping-tracker/ShippingFunction</module>
-        <module>todo-reminder/ToDoFunction</module>
+        <module>lambda-function</module>
+        <module>shipping-tracker-lambda/ShippingFunction</module>
+        <module>todo-reminder-lambda/ToDoFunction</module>
     </modules>
 
 </project>

aws-modules/aws-lambda-modules/shipping-tracker-lambda/ShippingFunction/pom.xml

@@ -2,7 +2,6 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>ShippingFunction</artifactId>
     <version>1.0</version>
     <name>ShippingFunction</name>
@@ -10,7 +9,7 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>aws-lambda</artifactId>
+        <artifactId>aws-lambda-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
         <relativePath>../../</relativePath>
     </parent>

aws-modules/aws-lambda-modules/todo-reminder-lambda/ToDoFunction/pom.xml

@@ -1,6 +1,6 @@
 <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/maven-v4_0_0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>helloworld</groupId>
     <artifactId>ToDoFunction</artifactId>
@@ -8,6 +8,13 @@
     <name>ToDoFunction</name>
     <packaging>jar</packaging>
 
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>aws-lambda-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../</relativePath>
+    </parent>
+
     <dependencies>
         <dependency>
             <groupId>com.amazonaws</groupId>

aws-modules/aws-lambda-modules/todo-reminder-lambda/ToDoFunction/src/test/java/com/baeldung/lambda/todo/AppUnitTest.java

@@ -21,7 +21,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.verify;
 
 @RunWith(MockitoJUnitRunner.class)
-public class AppTest {
+public class AppUnitTest {
 
     @Mock(answer = Answers.RETURNS_DEEP_STUBS)
     private Context mockContext;

aws-modules/aws-lambda-modules/todo-reminder-lambda/ToDoFunction/src/test/java/com/baeldung/lambda/todo/service/ToDoReaderServiceUnitTest.java

@@ -7,7 +7,7 @@ import uk.org.webcompere.systemstubs.rules.SystemOutRule;
 
 import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
 
-public class ToDoReaderServiceTest {
+public class ToDoReaderServiceUnitTest {
 
     @Rule
     public SystemOutRule systemOutRule = new SystemOutRule();

aws-modules/aws-s3/README.md

@@ -6,4 +6,5 @@ This module contains articles about Simple Storage Service (S3) on AWS
 
 - [AWS S3 with Java](https://www.baeldung.com/aws-s3-java)
 - [Multipart Uploads in Amazon S3 with Java](https://www.baeldung.com/aws-s3-multipart-upload)
-- [Using the JetS3t Java Client With Amazon S3](https://www.baeldung.com/jets3t-amazon-s3)
+- [Using the JetS3t Java Client With Amazon S3](https://www.baeldung.com/jets3t-amazon-s3)
+- [Check if a Specified Key Exists in a Given S3 Bucket Using Java](https://www.baeldung.com/java-aws-s3-check-specified-key-exists)

aws-modules/aws-s3/src/main/java/com/baeldung/s3/AWSS3ObjectUtils.java

@@ -0,0 +1,42 @@
+package com.baeldung.s3;
+
+import org.apache.http.HttpStatus;
+
+import com.amazonaws.AmazonServiceException;
+import com.amazonaws.services.s3.AmazonS3;
+
+public class AWSS3ObjectUtils {
+
+    private AmazonS3 s3Client;
+
+    public AWSS3ObjectUtils(AmazonS3 s3client) {
+        this.s3Client = s3client;
+    }
+
+    public boolean doesObjectExistByDefaultMethod(String bucket, String key) {
+        return s3Client.doesObjectExist(bucket, key);
+    }
+
+    public boolean doesObjectExistByListObjects(String bucket, String key) {
+        return s3Client.listObjects(bucket)
+            .getObjectSummaries()
+            .stream()
+            .filter(s3ObjectSummary -> s3ObjectSummary.getKey()
+                .equals(key))
+            .findFirst()
+            .isPresent();
+    }
+
+    public boolean doesObjectExistByMetaData(String bucket, String key) {
+        try {
+            s3Client.getObjectMetadata(bucket, key);
+            return true;
+        } catch (AmazonServiceException e) {
+            if (e.getStatusCode() == HttpStatus.SC_NOT_FOUND) {
+                return false;
+            } else {
+                throw e;
+            }
+        }
+    }
+}

aws-modules/aws-s3/src/test/java/com/baeldung/s3/AWSS3ObjectManualTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.s3;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.amazonaws.auth.EnvironmentVariableCredentialsProvider;
+import com.amazonaws.regions.Regions;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3ClientBuilder;
+
+/**
+ * Required defined environment variables AWS_ACCESS_KEY_ID & AWS_ACCESS_KEY to access S3.
+ * Required S3 bucket and key that exist.
+ */
+
+public class AWSS3ObjectManualTest {
+
+    private static final String BUCKET = "your-bucket";
+    private static final String KEY_THAT_EXIST = "your-key-that-exist";
+    private AWSS3ObjectUtils s3ObjectUtils;
+
+    @Before
+    public void setUp() {
+        AmazonS3 client = AmazonS3ClientBuilder.standard()
+            .withRegion(Regions.DEFAULT_REGION)
+            .withCredentials(new EnvironmentVariableCredentialsProvider())
+            .build();
+
+        s3ObjectUtils = new AWSS3ObjectUtils(client);
+    }
+
+    @Test
+    public void whenVerifyIfObjectExistByDefaultMethod_thenCorrect() {
+        assertTrue(s3ObjectUtils.doesObjectExistByDefaultMethod(BUCKET, KEY_THAT_EXIST), "Key: " + KEY_THAT_EXIST + " doesn't exist");
+
+    }
+
+    @Test
+    public void whenVerifyIfObjectExistByListObjects_thenCorrect() {
+        assertTrue(s3ObjectUtils.doesObjectExistByListObjects(BUCKET, KEY_THAT_EXIST), "Key: " + KEY_THAT_EXIST + " doesn't exist");
+    }
+
+    @Test
+    public void whenVerifyIfObjectExistByMetaData_thenCorrect() {
+        assertTrue(s3ObjectUtils.doesObjectExistByMetaData(BUCKET, KEY_THAT_EXIST), "Key: " + KEY_THAT_EXIST + " doesn't exist");
+    }
+}

aws-modules/pom.xml

@@ -15,7 +15,7 @@
 
     <modules>
         <module>aws-app-sync</module>
-        <module>aws-lambda</module>
+        <module>aws-lambda-modules</module>
         <module>aws-miscellaneous</module>
         <module>aws-reactive</module>
         <module>aws-s3</module>

axon/pom.xml

@@ -103,7 +103,8 @@
                 <configuration>
                     <argLine>
                         --add-opens java.base/java.util=ALL-UNNAMED
-                        --add-opens java.base/java.util.concurrent=ALL-UNNAMED
+                        --add-opens
+                        java.base/java.util.concurrent=ALL-UNNAMED
                     </argLine>
                 </configuration>
             </plugin>

checker-framework/pom.xml

@@ -3,11 +3,10 @@
     xmlns="http://maven.apache.org/POM/4.0.0"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>checker-plugin</artifactId>
+    <artifactId>checker-framework</artifactId>
     <version>1.0-SNAPSHOT</version>
-    <name>checker-plugin</name>
+    <name>checker-framework</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-groovy-modules/core-groovy-2/pom.xml

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy-2</artifactId>
-    <version>1.0-SNAPSHOT</version>
     <name>core-groovy-2</name>
     <packaging>jar</packaging>
 
@@ -153,14 +152,6 @@
         </plugins>
     </build>
 
-    <repositories>
-        <repository>
-            <id>maven_central</id>
-            <name>Maven Central</name>
-            <url>https://repo.maven.apache.org/maven2/</url>
-        </repository>
-    </repositories>
-
     <properties>
         <groovy-wslite.version>1.1.3</groovy-wslite.version>
         <assembly.plugin.version>3.4.2</assembly.plugin.version>

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

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy-collections</artifactId>
-    <version>1.0-SNAPSHOT</version>
     <name>core-groovy-collections</name>
     <packaging>jar</packaging>
 
@@ -111,13 +110,4 @@
         </plugins>
     </build>
 
-    <repositories>
-        <repository>
-            <id>maven_central</id>
-            <name>Maven Central</name>
-            <url>https://repo.maven.apache.org/maven2/</url>
-        </repository>
-    </repositories>
-
-
 </project>

core-groovy-modules/core-groovy-strings/pom.xml

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy-strings</artifactId>
-    <version>1.0-SNAPSHOT</version>
     <name>core-groovy-strings</name>
     <packaging>jar</packaging>
 
@@ -101,12 +100,4 @@
         </plugins>
     </build>
 
-    <repositories>
-        <repository>
-            <id>maven_central</id>
-            <name>Maven Central</name>
-            <url>https://repo.maven.apache.org/maven2/</url>
-        </repository>
-    </repositories>
-
 </project>

core-groovy-modules/core-groovy/pom.xml

@@ -3,9 +3,7 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    
     <artifactId>core-groovy</artifactId>
-    <version>1.0-SNAPSHOT</version>
     <name>core-groovy</name>
     <packaging>jar</packaging>
 
@@ -102,12 +100,4 @@
         </plugins>
     </build>
 
-    <repositories>
-        <repository>
-            <id>maven_central</id>
-            <name>Maven Central</name>
-            <url>https://repo.maven.apache.org/maven2/</url>
-        </repository>
-    </repositories>
-
 </project>

core-java-modules/core-java-10/pom.xml

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-10</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-10</name>
     <packaging>jar</packaging>
 

core-java-modules/core-java-11-2/pom.xml

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-11-2</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-11-2</name>
     <packaging>jar</packaging>
 

core-java-modules/core-java-11-3/pom.xml

@@ -4,7 +4,6 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-11-3</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-11-3</name>
     <packaging>jar</packaging>
 
@@ -14,7 +13,7 @@
         <version>1.0.0-SNAPSHOT</version>
         <relativePath>../../pom.xml</relativePath>
     </parent>
-    
+
     <dependencies>
         <dependency>
             <groupId>com.google.code.gson</groupId>

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

@@ -4,10 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-11</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-11</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-12/pom.xml

@@ -4,10 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-12</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-12</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-13/pom.xml

@@ -3,12 +3,9 @@
     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-13</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-13</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-14/pom.xml

@@ -6,7 +6,6 @@
     <artifactId>core-java-14</artifactId>
     <name>core-java-14</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-15/pom.xml

@@ -6,7 +6,6 @@
     <artifactId>core-java-15</artifactId>
     <name>core-java-15</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-16/pom.xml

@@ -4,10 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-16</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-16</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-17/pom.xml

@@ -4,10 +4,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-java-17</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
     <name>core-java-17</name>
     <packaging>jar</packaging>
-    <url>http://maven.apache.org</url>
 
     <parent>
         <groupId>com.baeldung</groupId>

core-java-modules/core-java-19/README.md

@@ -1,3 +1,4 @@
 ## Relevant Articles
 - [Record Patterns in Java 19](https://www.baeldung.com/java-19-record-patterns)
 - [Structured Concurrency in Java 19](https://www.baeldung.com/java-structured-concurrency)
+- [Possible Root Causes for High CPU Usage in Java](https://www.baeldung.com/java-high-cpu-usage-causes)

core-java-modules/core-java-19/pom.xml

@@ -1,21 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-19</artifactId>
+    <name>core-java-19</name>
+
     <parent>
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <artifactId>core-java-19</artifactId>
-
-    <properties>
-        <maven.compiler.source>19</maven.compiler.source>
-        <maven.compiler.target>19</maven.compiler.target>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    </properties>
     <build>
         <plugins>
             <plugin>
@@ -30,4 +26,10 @@
         </plugins>
     </build>
 
+    <properties>
+        <maven.compiler.source>19</maven.compiler.source>
+        <maven.compiler.target>19</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
 </project>

core-java-modules/core-java-19/src/main/java/com/baeldung/highcpu/Application.java

@@ -0,0 +1,20 @@
+package com.baeldung.highcpu;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.function.IntUnaryOperator;
+import java.util.stream.IntStream;
+
+public class Application {
+
+    static List<Integer> generateList() {
+        return IntStream.range(0, 10000000).parallel().map(IntUnaryOperator.identity()).collect(LinkedList::new, List::add, List::addAll);
+    }
+
+    public static void main(String[] args) {
+        List<Integer> list = generateList();
+        long start = System.nanoTime();
+        int value = list.get(9500000);
+        System.out.printf("Found value %d in %d nanos\n", value, (System.nanoTime() - start));
+    }
+}