Merge branch 'master' into BAEL-4406-jacoco-exclusions

2021-06-03 21:57:38 +01:00
parent 443c0c7850 bf5b25b7a6
commit 08843a0141
43 changed files with 1762 additions and 1 deletions
@@ -0,0 +1 @@
+.aws-sam/
@@ -6,3 +6,4 @@ This module contains articles about AWS Lambda
 - [Using AWS Lambda with API Gateway](https://www.baeldung.com/aws-lambda-api-gateway)
 - [Introduction to AWS Serverless Application Model](https://www.baeldung.com/aws-serverless)
 - [How to Implement Hibernate in an AWS Lambda Function in Java](https://www.baeldung.com/java-aws-lambda-hibernate)
+- [Writing an Enterprise-Grade AWS Lambda in Java](https://www.baeldung.com/java-enterprise-aws-lambda)
@@ -17,6 +17,7 @@
    <modules>
        <module>lambda</module>
        <module>shipping-tracker/ShippingFunction</module>
+        <module>todo-reminder/ToDoFunction</module>
    </modules>

 </project>
@@ -0,0 +1,105 @@
+<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">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>helloworld</groupId>
+    <artifactId>HelloWorld</artifactId>
+    <version>1.0</version>
+    <packaging>jar</packaging>
+    <name>To Do Application Example.</name>
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-lambda-java-core</artifactId>
+            <version>1.2.1</version>
+        </dependency>
+        <dependency>
+          <groupId>com.amazonaws</groupId>
+          <artifactId>aws-lambda-java-events</artifactId>
+          <version>3.6.0</version>
+        </dependency>
+        <dependency>
+            <groupId>uk.org.webcompere</groupId>
+            <artifactId>lightweight-config</artifactId>
+            <version>1.1.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-lambda-java-log4j2</artifactId>
+            <version>1.2.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-slf4j-impl</artifactId>
+            <version>2.13.2</version>
+        </dependency>
+        <dependency>
+            <groupId>io.github.openfeign</groupId>
+            <artifactId>feign-core</artifactId>
+            <version>11.2</version>
+        </dependency>
+        <dependency>
+            <groupId>io.github.openfeign</groupId>
+            <artifactId>feign-slf4j</artifactId>
+            <version>11.2</version>
+        </dependency>
+        <dependency>
+            <groupId>io.github.openfeign</groupId>
+            <artifactId>feign-gson</artifactId>
+            <version>11.2</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.inject</groupId>
+            <artifactId>guice</artifactId>
+            <version>5.0.1</version>
+        </dependency>
+        <dependency>
+          <groupId>junit</groupId>
+          <artifactId>junit</artifactId>
+          <version>4.13.1</version>
+          <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>uk.org.webcompere</groupId>
+            <artifactId>system-stubs-junit4</artifactId>
+            <version>1.2.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>3.3.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.19.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-shade-plugin</artifactId>
+          <version>3.2.4</version>
+          <configuration>
+          </configuration>
+          <executions>
+            <execution>
+              <phase>package</phase>
+              <goals>
+                <goal>shade</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+      </plugins>
+    </build>
+</project>
@@ -0,0 +1,43 @@
+package com.baeldung.lambda.todo;
+
+import java.io.*;
+import java.net.URL;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+import com.amazonaws.services.lambda.runtime.RequestStreamHandler;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
+import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
+import com.baeldung.lambda.todo.config.ExecutionContext;
+import com.baeldung.lambda.todo.service.PostService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Handler for requests to Lambda function.
+ */
+public class App implements RequestStreamHandler {
+    private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
+    private String environmentName = System.getenv("ENV_NAME");
+    private ExecutionContext executionContext = new ExecutionContext();
+
+    @Override
+    public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException {
+        context.getLogger().log("App starting\n");
+        context.getLogger().log("Environment: "
+          + environmentName + "\n");
+
+        try {
+            PostService postService = executionContext.getPostService();
+            executionContext.getToDoReaderService()
+              .getOldestToDo()
+              .ifPresent(postService::makePost);
+        } catch (Exception e) {
+            LOGGER.error("Failed: {}", e.getMessage(), e);
+        }
+    }
+}
@@ -0,0 +1,8 @@
+package com.baeldung.lambda.todo.api;
+
+import feign.RequestLine;
+
+public interface PostApi {
+    @RequestLine("POST /posts")
+    void makePost(PostItem item);
+}
@@ -0,0 +1,40 @@
+package com.baeldung.lambda.todo.api;
+
+public class PostItem {
+    private String title;
+    private String body;
+    private int userId;
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getBody() {
+        return body;
+    }
+
+    public void setBody(String body) {
+        this.body = body;
+    }
+
+    public int getUserId() {
+        return userId;
+    }
+
+    public void setUserId(int userId) {
+        this.userId = userId;
+    }
+
+    @Override
+    public String toString() {
+        return "PostItem{"
+          + "title='" + title + '\''
+          + ", body='" + body + '\''
+          + ", userId=" + userId +
+          '}';
+    }
+}
@@ -0,0 +1,10 @@
+package com.baeldung.lambda.todo.api;
+
+import feign.RequestLine;
+
+import java.util.List;
+
+public interface ToDoApi {
+    @RequestLine("GET /todos")
+    List<ToDoItem> getAllTodos();
+}
@@ -0,0 +1,50 @@
+package com.baeldung.lambda.todo.api;
+
+public class ToDoItem {
+    private int userId;
+    private int id;
+    private String title;
+    private boolean completed;
+
+    public int getUserId() {
+        return userId;
+    }
+
+    public void setUserId(int userId) {
+        this.userId = userId;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public boolean isCompleted() {
+        return completed;
+    }
+
+    public void setCompleted(boolean completed) {
+        this.completed = completed;
+    }
+
+    @Override
+    public String toString() {
+        return "ToDoItem{"
+          + "userId=" + userId
+          + ", id=" + id
+          + ", title='" + title + '\''
+          + ", completed=" + completed +
+          '}';
+    }
+}
@@ -0,0 +1,50 @@
+package com.baeldung.lambda.todo.config;
+
+public class Config {
+    private String toDoEndpoint;
+    private String postEndpoint;
+    private String environmentName;
+
+    private Credentials toDoCredentials;
+    private Credentials postCredentials;
+
+    public String getToDoEndpoint() {
+        return toDoEndpoint;
+    }
+
+    public void setToDoEndpoint(String toDoEndpoint) {
+        this.toDoEndpoint = toDoEndpoint;
+    }
+
+    public String getPostEndpoint() {
+        return postEndpoint;
+    }
+
+    public void setPostEndpoint(String postEndpoint) {
+        this.postEndpoint = postEndpoint;
+    }
+
+    public String getEnvironmentName() {
+        return environmentName;
+    }
+
+    public void setEnvironmentName(String environmentName) {
+        this.environmentName = environmentName;
+    }
+
+    public Credentials getToDoCredentials() {
+        return toDoCredentials;
+    }
+
+    public void setToDoCredentials(Credentials toDoCredentials) {
+        this.toDoCredentials = toDoCredentials;
+    }
+
+    public Credentials getPostCredentials() {
+        return postCredentials;
+    }
+
+    public void setPostCredentials(Credentials postCredentials) {
+        this.postCredentials = postCredentials;
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.lambda.todo.config;
+
+public class Credentials {
+    private String username;
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+}
@@ -0,0 +1,36 @@
+package com.baeldung.lambda.todo.config;
+
+import com.baeldung.lambda.todo.service.PostService;
+import com.baeldung.lambda.todo.service.ToDoReaderService;
+import com.google.inject.Guice;
+import com.google.inject.Injector;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ExecutionContext {
+    private static final Logger LOGGER =
+            LoggerFactory.getLogger(ExecutionContext.class);
+
+    private ToDoReaderService toDoReaderService;
+    private PostService postService;
+
+    public ExecutionContext() {
+        LOGGER.info("Loading configuration");
+
+        try {
+            Injector injector = Guice.createInjector(new Services());
+            this.toDoReaderService = injector.getInstance(ToDoReaderService.class);
+            this.postService = injector.getInstance(PostService.class);
+        } catch (Exception e) {
+            LOGGER.error("Could not start", e);
+        }
+    }
+
+    public ToDoReaderService getToDoReaderService() {
+        return toDoReaderService;
+    }
+
+    public PostService getPostService() {
+        return postService;
+    }
+}
@@ -0,0 +1,38 @@
+package com.baeldung.lambda.todo.config;
+
+import com.baeldung.lambda.todo.api.PostApi;
+import com.baeldung.lambda.todo.api.ToDoApi;
+import com.google.inject.AbstractModule;
+import feign.Feign;
+import feign.auth.BasicAuthRequestInterceptor;
+import feign.gson.GsonDecoder;
+import feign.gson.GsonEncoder;
+import feign.slf4j.Slf4jLogger;
+import uk.org.webcompere.lightweightconfig.ConfigLoader;
+
+import static feign.Logger.Level.FULL;
+
+public class Services extends AbstractModule {
+    @Override
+    protected void configure() {
+        Config config = ConfigLoader.loadYmlConfigFromResource("configuration.yml", Config.class);
+
+        ToDoApi toDoApi = Feign.builder()
+          .decoder(new GsonDecoder())
+          .logger(new Slf4jLogger())
+          .logLevel(FULL)
+          .requestInterceptor(new BasicAuthRequestInterceptor(config.getToDoCredentials().getUsername(), config.getToDoCredentials().getPassword()))
+          .target(ToDoApi.class, config.getToDoEndpoint());
+
+        PostApi postApi = Feign.builder()
+          .encoder(new GsonEncoder())
+          .logger(new Slf4jLogger())
+          .logLevel(FULL)
+          .requestInterceptor(new BasicAuthRequestInterceptor(config.getPostCredentials().getUsername(), config.getPostCredentials().getPassword()))
+          .target(PostApi.class, config.getPostEndpoint());
+
+        bind(Config.class).toInstance(config);
+        bind(ToDoApi.class).toInstance(toDoApi);
+        bind(PostApi.class).toInstance(postApi);
+    }
+}
@@ -0,0 +1,30 @@
+package com.baeldung.lambda.todo.service;
+
+import com.baeldung.lambda.todo.api.PostApi;
+import com.baeldung.lambda.todo.api.PostItem;
+import com.baeldung.lambda.todo.api.ToDoItem;
+import com.google.inject.Inject;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+
+public class PostService {
+    private static final Logger LOGGER = LogManager.getLogger(PostService.class);
+    private PostApi postApi;
+
+    @Inject
+    public PostService(PostApi postApi) {
+        this.postApi = postApi;
+    }
+
+    public void makePost(ToDoItem toDoItem) {
+        LOGGER.info("Posting about: {}", toDoItem);
+        PostItem item = new PostItem();
+        item.setTitle("To Do is Out Of Date: " + toDoItem.getId());
+        item.setUserId(toDoItem.getUserId());
+        item.setBody("Not done: " + toDoItem.getTitle());
+
+        LOGGER.info("Post: {}", item);
+        postApi.makePost(item);
+    }
+}
@@ -0,0 +1,30 @@
+package com.baeldung.lambda.todo.service;
+
+import com.baeldung.lambda.todo.api.ToDoApi;
+import com.baeldung.lambda.todo.api.ToDoItem;
+import com.baeldung.lambda.todo.config.Config;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import javax.inject.Inject;
+import java.util.Optional;
+
+public class ToDoReaderService {
+    // Log4j logger
+    private static final Logger LOGGER = LogManager.getLogger(ToDoReaderService.class);
+
+    private ToDoApi toDoApi;
+
+    @Inject
+    public ToDoReaderService(Config configuration, ToDoApi toDoApi) {
+        LOGGER.info("ToDo Endpoint on: {}", configuration.getToDoEndpoint());
+
+        this.toDoApi = toDoApi;
+    }
+
+    public Optional<ToDoItem> getOldestToDo() {
+        return toDoApi.getAllTodos().stream()
+          .filter(item -> !item.isCompleted())
+          .findFirst();
+    }
+}
@@ -0,0 +1,9 @@
+toDoEndpoint: https://jsonplaceholder.typicode.com
+postEndpoint: https://jsonplaceholder.typicode.com
+environmentName: ${ENV_NAME}
+toDoCredentials:
+  username: baeldung
+  password: ${TODO_PASSWORD:-password}
+postCredentials:
+  username: baeldung
+  password: ${POST_PASSWORD:-password}
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration packages="com.amazonaws.services.lambda.runtime.log4j2">
+    <Appenders>
+        <Lambda name="Lambda">
+            <PatternLayout>
+                <pattern>%d{yyyy-MM-dd HH:mm:ss} %X{AWSRequestId} %-5p %c{1} - %m%n</pattern>
+            </PatternLayout>
+        </Lambda>
+    </Appenders>
+    <Loggers>
+        <Root level="info">
+            <AppenderRef ref="Lambda" />
+        </Root>
+    </Loggers>
+</Configuration>
@@ -0,0 +1,58 @@
+package com.baeldung.lambda.todo;
+
+import com.amazonaws.services.lambda.runtime.Context;
+import com.baeldung.lambda.todo.config.Config;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Answers;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+import uk.org.webcompere.lightweightconfig.ConfigLoader;
+import uk.org.webcompere.systemstubs.rules.EnvironmentVariablesRule;
+import uk.org.webcompere.systemstubs.stream.input.LinesAltStream;
+import uk.org.webcompere.systemstubs.stream.output.NoopStream;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.verify;
+
+@RunWith(MockitoJUnitRunner.class)
+public class AppTest {
+
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private Context mockContext;
+
+    @Rule
+    public EnvironmentVariablesRule environmentVariablesRule = new EnvironmentVariablesRule();
+
+    private InputStream fakeInputStream = new LinesAltStream();
+    private OutputStream fakeOutputStream = new NoopStream();
+
+    @Test
+    public void whenTheEnvironmentVariableIsSet_thenItIsLogged() throws Exception {
+        environmentVariablesRule.set("ENV_NAME", "unitTest");
+        new App().handleRequest(fakeInputStream, fakeOutputStream, mockContext);
+
+        verify(mockContext.getLogger())
+          .log("Environment: unitTest\n");
+    }
+
+    @Test
+    public void givenEnvironmentVariableIsNotSet_thenUseDefault() {
+        String setting = Optional.ofNullable(System.getenv("SETTING"))
+          .orElse("default");
+
+        assertThat(setting).isEqualTo("default");
+    }
+
+    @Test
+    public void givenConfiguration_canLoadIntoPojo() {
+        environmentVariablesRule.set("ENV_NAME", "unitTest");
+        Config config = ConfigLoader.loadYmlConfigFromResource("configuration.yml", Config.class);
+        assertThat(config.getEnvironmentName()).isEqualTo("unitTest");
+    }
+}
@@ -0,0 +1,24 @@
+package com.baeldung.lambda.todo.service;
+
+import com.baeldung.lambda.todo.config.Config;
+import org.junit.Rule;
+import org.junit.Test;
+import uk.org.webcompere.systemstubs.rules.SystemOutRule;
+
+import static org.assertj.core.api.AssertionsForInterfaceTypes.assertThat;
+
+public class ToDoReaderServiceTest {
+
+    @Rule
+    public SystemOutRule systemOutRule = new SystemOutRule();
+
+    @Test
+    public void whenTheServiceStarts_thenItOutputsEndpoint() {
+        Config config = new Config();
+        config.setToDoEndpoint("https://todo-endpoint.com");
+        ToDoReaderService service = new ToDoReaderService(config, null);
+
+        assertThat(systemOutRule.getLinesNormalized())
+          .contains("ToDo Endpoint on: https://todo-endpoint.com");
+    }
+}
@@ -0,0 +1,22 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: todo-reminder application
+
+Parameters:
+  EnvironmentName:
+    Type: String
+    Default: dev
+
+Resources:
+  ToDoFunction:
+    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
+    Properties:
+      Timeout: 20
+      CodeUri: ToDoFunction
+      Handler: com.baeldung.lambda.todo.App::handleRequest
+      Runtime: java8
+      MemorySize: 512
+      Environment: # More info about Env Vars: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#environment-object
+        Variables:
+          PARAM1: VALUE
+          ENV_NAME: !Ref EnvironmentName
@@ -8,3 +8,4 @@ This module contains complete guides about arrays in Java
 - [What is \[Ljava.lang.Object;?](https://www.baeldung.com/java-tostring-array)
 - [Guide to ArrayStoreException](https://www.baeldung.com/java-arraystoreexception)
 - [Creating a Generic Array in Java](https://www.baeldung.com/java-generic-array)
+- [Maximum Size of Java Arrays](https://www.baeldung.com/java-arrays-max-size)
@@ -8,3 +8,4 @@
 - [Localizing Exception Messages in Java](https://www.baeldung.com/java-localize-exception-messages)
 - [Explanation of ClassCastException in Java](https://www.baeldung.com/java-classcastexception)
 - [NoSuchFieldError in Java](https://www.baeldung.com/java-nosuchfielderror)
+- [IllegalAccessError in Java](https://www.baeldung.com/java-illegalaccesserror)
@@ -5,4 +5,5 @@ This module contains articles about networking in Java
 ### Relevant Articles

 - [Finding a Free Port in Java](https://www.baeldung.com/java-free-port)
+- [Downloading Email Attachments in Java](https://www.baeldung.com/java-download-email-attachments)
 - [[<-- Prev]](/core-java-modules/core-java-networking-2)
@@ -5,3 +5,4 @@
 - [Checking If a Method is Static Using Reflection in Java](https://www.baeldung.com/java-check-method-is-static)
 - [Checking if a Java Class is ‘abstract’ Using Reflection](https://www.baeldung.com/java-reflection-is-class-abstract)
 - [Invoking a Private Method in Java](https://www.baeldung.com/java-call-private-method)
+- [Finding All Classes in a Java Package](https://www.baeldung.com/java-find-all-classes-in-package)
@@ -13,3 +13,4 @@
 - [Regular Expressions \s and \s+ in Java](https://www.baeldung.com/java-regex-s-splus)
 - [Validate Phone Numbers With Java Regex](https://www.baeldung.com/java-regex-validate-phone-numbers)
 - [How to Count the Number of Matches for a Regex?](https://www.baeldung.com/java-count-regex-matches)
+- [Find All Numbers in a String in Java](https://www.baeldung.com/java-find-numbers-in-string)
@@ -0,0 +1,77 @@
+package com.baeldung.regex.countdigits;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.junit.jupiter.api.Test;
+
+import com.google.common.base.CharMatcher;
+
+/**
+ * Unit Test to count the number of digits in a String
+ */
+class CountDigitsUnitTest {
+
+    // Guava CharMatcher to match digits
+    private static final CharMatcher DIGIT_CHAR_MATCHER = CharMatcher.inRange('0', '9');
+    
+    private static final String STR_WITH_ALL_DIGITS = "970987678607608";
+    private static final String STR_WITH_SINGLE_DIGITS_SEP_BY_NON_DIGITS = "9kjl()4f*(&6~3dfd8&5dfd8a";
+    private static final String STR_WITH_SEQUENCES_OF_1_OR_MORE_DIGITS_SEP_BY_NON_DIGITS
+      = "64.6lk.l~453lkdsf9wg038.68*()(k;95786fsd7986";
+    
+    private static int countDigits(String stringToSearch) {
+        Matcher countEmailMatcher = Pattern.compile("\\d").matcher(stringToSearch);
+
+        int count = 0;
+        while (countEmailMatcher.find()) {
+            count++;
+        }
+
+        return count;
+    }
+
+    @Test
+    void givenStrOfAllDigits_whenRegexMatchByDigit_thenFifteenDigitsCounted() {
+        int count = countDigits(STR_WITH_ALL_DIGITS);
+
+        assertThat(count).isEqualTo(15);
+    }
+
+    @Test
+    void givenStrWithSingleDigitsSepByNonDigits_whenRegexMatchByDigit_thenSevenDigitsCounted() {
+        int count = countDigits(STR_WITH_SINGLE_DIGITS_SEP_BY_NON_DIGITS);
+
+        assertThat(count).isEqualTo(7);
+    }
+
+    @Test
+    void givenStrWithOneOrMoreDigitsSepByNonDigits_whenRegexMatchByDigit_thenTwentyOneDigitsCounted() {
+        int count = countDigits(STR_WITH_SEQUENCES_OF_1_OR_MORE_DIGITS_SEP_BY_NON_DIGITS);
+
+        assertThat(count).isEqualTo(21);
+    }
+    
+    @Test
+    void givenStrOfAllDigits_whenGuavaCharMatchByDigit_thenFifteenDigitsCounted() {
+        int count = DIGIT_CHAR_MATCHER.countIn(STR_WITH_ALL_DIGITS);
+
+        assertThat(count).isEqualTo(15);
+    }
+    
+    @Test
+    void givenStrWithSingleDigitsSepByNonDigits_whenGuavaCharMatchByDigit_thenSevenDigitsCounted() {
+        int count = DIGIT_CHAR_MATCHER.countIn(STR_WITH_SINGLE_DIGITS_SEP_BY_NON_DIGITS);
+
+        assertThat(count).isEqualTo(7);
+    }
+    
+    @Test
+    void givenStrWithOneOrMoreDigitsSepByNonDigits_whenGuavaCharMatchByDigit_thenTwentyOneDigitsCounted() {
+        int count = DIGIT_CHAR_MATCHER.countIn(STR_WITH_SEQUENCES_OF_1_OR_MORE_DIGITS_SEP_BY_NON_DIGITS);
+
+        assertThat(count).isEqualTo(21);
+    }
+}
@@ -0,0 +1,128 @@
+package com.baeldung.regex.findnumbers;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.DoubleStream;
+import java.util.stream.LongStream;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit Test to find Integers, Decimal Numbers, and Scientific Notation and Hexadecimal Numbers in a String
+ */
+class FindNumbersUnitTest {
+
+    private static List<String> findIntegers(String stringToSearch) {
+        Pattern integerPattern = Pattern.compile("-?\\d+");
+        Matcher matcher = integerPattern.matcher(stringToSearch);
+
+        List<String> integerList = new ArrayList<>();
+        while (matcher.find()) {
+            integerList.add(matcher.group());
+        }
+
+        return integerList;
+    }
+
+    private static List<String> findDecimalNums(String stringToSearch) {
+        Pattern decimalNumPattern = Pattern.compile("-?\\d+(\\.\\d+)?");
+        Matcher matcher = decimalNumPattern.matcher(stringToSearch);
+
+        List<String> decimalNumList = new ArrayList<>();
+        while (matcher.find()) {
+            decimalNumList.add(matcher.group());
+        }
+
+        return decimalNumList;
+    }
+
+    @Test
+    void givenStrOfAllDigits_whenRegexMatchByInt_thenWholeStrMatchedAsOneInt() {     
+        List<String> integersFound = findIntegers("970987678607608");
+
+        assertThat(integersFound).containsExactly("970987678607608");
+    }
+
+    @Test
+    void givenStrWithIntegersSepByPeriods_whenRegexMatchByInt_thenExpectedIntsFound() {
+        List<String> integersFound = findIntegers("3453..5.-23532...32432.-2363.3454......345.-34.");
+
+        assertThat(integersFound).containsExactly("3453", "5", "-23532", "32432", "-2363", "3454", "345", "-34");
+    }
+
+    @Test
+    void givenStrWithIntegersSepByNonDigits_whenRegexMatchByInt_thenExpectedIntsFound() {
+        List<String> integersFound = findIntegers("646lkl~4-53l-k34.fdsf.-ds-35.45f9wg3868*()(k;-95786fsd79-86");
+
+        assertThat(integersFound).containsExactly("646", "4", "-53", "34", "-35", "45", "9", "3868", "-95786", "79", "-86");
+    }
+    
+    @Test
+    void givenStrOfAllDigits_whenRegexMatchByDecNum_thenWholeStrMatchedAsOneDecimalNumber() {
+        List<String> decimalNumsFound = findDecimalNums("970987678607608");
+        
+        assertThat(decimalNumsFound).containsExactly("970987678607608");
+    }
+    
+    @Test
+    void givenStrOfDecNumsSepByNonDigits_whenRegexMatchByDecNum_thenExpectedNumsFound() {
+        List<String> decimalNumsFound = findDecimalNums(".7854.455wo.rdy(do.g)-3.-553.00.53;good^night%o3456sdcardR%3567.4%£cat");
+        
+        assertThat(decimalNumsFound).containsExactly("7854.455", "-3", "-553.00", "53", "3456", "3567.4");
+    }
+    
+    @Test
+    void givenStrWithRandomDigitsDashesAndPeriods_whenRegexMatchByDecNum_thenExpectedNumsFound() {
+        List<String> decimalNumsFound = findDecimalNums(".-..90834.345.--493-..-85.-875.345-.-.-355.345...345.-.636-5.6-3.");
+        
+        assertThat(decimalNumsFound).containsExactly("90834.345", "-493", "-85", "-875.345", "-355.345", "345", "636", "-5.6", "-3");
+    }
+    
+    @Test
+    void givenStrOfIntsSepByNonDigits_whenRegexMatchByInt_thenExpectedValuesFound() {
+        LongStream integerValuesFound = findIntegers(".7854.455wo.rdy(do.g)-3.ght%o34.56")
+          .stream().mapToLong(Long::valueOf);
+        
+        assertThat(integerValuesFound).containsExactly(7854L, 455L, -3L, 34L, 56L);
+    }    
+    
+    @Test
+    void givenStrOfDecNumsSepByNonDigits_whenRegexMatchByDecNum_thenExpectedValuesFound() {
+        DoubleStream decimalNumValuesFound = findDecimalNums(".7854.455wo.rdy(do.g)-3.ght%o34.56")
+          .stream().mapToDouble(Double::valueOf);
+        
+        assertThat(decimalNumValuesFound).containsExactly(7854.455, -3.0, 34.56);
+    }
+    
+    @Test
+    void givenStrOfSciNotationNumsSepByNonDigits_whenRegexMatchBySciNotNum_thenExpectedNumsFound() {
+        String strToSearch = "}s1.25E-3>,/@l2e109he-70.96E+105d£d_-8.7312E-102=#;,.d919.3822e+31e]";
+        
+        Matcher matcher = Pattern.compile("-?\\d+(\\.\\d+)?[eE][+-]?\\d+")
+          .matcher(strToSearch);
+        List<String> sciNotationNums = new ArrayList<>();
+        while (matcher.find()) {
+            sciNotationNums.add(matcher.group());
+        }
+        
+        assertThat(sciNotationNums).containsExactly("1.25E-3", "2e109", "-70.96E+105", "-8.7312E-102", "919.3822e+31");
+    }
+    
+    @Test
+    void givenStrOfHexNumsSepByNonDigits_whenRegexMatchByHexNum_thenExpectedNumsFound() {
+        String strToSearch = "}saF851Bq-3f6Cm>,/@j-2Ad9eE>70ae19.>";
+        
+        Matcher matcher = Pattern.compile("-?[0-9a-fA-F]+")
+          .matcher(strToSearch);
+        List<String> hexNums = new ArrayList<>();
+        while (matcher.find()) {
+            hexNums.add(matcher.group());
+        }
+        
+        assertThat(hexNums).containsExactly("aF851B", "-3f6C", "-2Ad9eE", "70ae19");
+    }
+}
@@ -4,5 +4,5 @@ This module contains articles about core Java Security

 ### Relevant Articles:

- [Secret Key and String Conversion in Java](https://www.baeldung.com/secret-key-and-string-conversion-in-java/)
+- [Secret Key and String Conversion in Java](https://www.baeldung.com/java-secret-key-to-string)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security-2)
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Using Cucumber with Gradle](https://www.baeldung.com/java-cucumber-gradle)
@@ -17,6 +17,7 @@
            <artifactId>client-java</artifactId>
            <version>11.0.0</version>
        </dependency>
+
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
--- a/Show More
+++ b/Show More