Initial Commit

.gitignore

+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

.mvn/wrapper/maven-wrapper.properties

+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.5/apache-maven-3.9.5-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar

mvnw.cmd

+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Apache Maven Wrapper startup batch script, version 3.2.0
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_pre.bat" call "%USERPROFILE%\mavenrc_pre.bat" %*
+if exist "%USERPROFILE%\mavenrc_pre.cmd" call "%USERPROFILE%\mavenrc_pre.cmd" %*
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set WRAPPER_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET WRAPPER_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET WRAPPER_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %WRAPPER_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%WRAPPER_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM If specified, validate the SHA-256 sum of the Maven wrapper jar file
+SET WRAPPER_SHA_256_SUM=""
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperSha256Sum" SET WRAPPER_SHA_256_SUM=%%B
+)
+IF NOT %WRAPPER_SHA_256_SUM%=="" (
+    powershell -Command "&{"^
+       "$hash = (Get-FileHash \"%WRAPPER_JAR%\" -Algorithm SHA256).Hash.ToLower();"^
+       "If('%WRAPPER_SHA_256_SUM%' -ne $hash){"^
+       "  Write-Output 'Error: Failed to validate Maven wrapper SHA-256, your Maven wrapper might be compromised.';"^
+       "  Write-Output 'Investigate or delete %WRAPPER_JAR% to attempt a clean download.';"^
+       "  Write-Output 'If you updated your Maven version, you need to update the specified wrapperSha256Sum property.';"^
+       "  exit 1;"^
+       "}"^
+       "}"
+    if ERRORLEVEL 1 goto error
+)
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% ^
+  %JVM_CONFIG_MAVEN_PROPS% ^
+  %MAVEN_OPTS% ^
+  %MAVEN_DEBUG_OPTS% ^
+  -classpath %WRAPPER_JAR% ^
+  "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" ^
+  %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%"=="" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat"
+if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%"=="on" pause
+
+if "%MAVEN_TERMINATE_CMD%"=="on" exit %ERROR_CODE%
+
+cmd /C exit /B %ERROR_CODE%

pom.xml

+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>3.2.2</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.kafka</groupId>
+	<artifactId>springboot-kafka-tutorial</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>springboot-kafka-tutorial</name>
+	<description>Demo project for Kafka</description>
+	<properties>
+		<java.version>17</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

src/main/java/com/kafka/springbootkafkatutorial/SpringbootKafkaTutorialApplication.java

+package com.kafka.springbootkafkatutorial;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringbootKafkaTutorialApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(SpringbootKafkaTutorialApplication.class, args);
+	}
+
+}

src/main/java/com/kafka/springbootkafkatutorial/config/KafkaTopicConfig.java

+package com.kafka.springbootkafkatutorial.config;
+
+import org.apache.kafka.clients.admin.NewTopic;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.kafka.config.TopicBuilder;
+
+@Configuration
+public class KafkaTopicConfig {
+
+    @Value("${spring.kafka.topic.name}")
+    private String topicName;
+
+    @Value("${spring.kafka.topic-json.name}")
+    private String jsonTopicName;
+
+    @Bean
+    public NewTopic createTopic(){
+        return TopicBuilder.name(topicName).build();
+    }
+
+    @Bean
+    public NewTopic createJsonTopic(){
+        return TopicBuilder.name(jsonTopicName).build();
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/controller/JsonMessageController.java

+package com.kafka.springbootkafkatutorial.controller;
+
+import com.kafka.springbootkafkatutorial.kafka.KafkaJsonProducer;
+import com.kafka.springbootkafkatutorial.payload.User;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/v1/kafka")
+public class JsonMessageController {
+
+    private final KafkaJsonProducer kafkaJsonProducer;
+
+    public JsonMessageController(KafkaJsonProducer kafkaJsonProducer) {
+        this.kafkaJsonProducer = kafkaJsonProducer;
+    }
+
+
+    @PostMapping("/publish")
+    public ResponseEntity<String> sendMessageToKafka(@RequestBody User user){
+        kafkaJsonProducer.sendMessage(user);
+        return ResponseEntity.ok("Json message sent to kafka topic");
+
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/controller/KafkaController.java

+package com.kafka.springbootkafkatutorial.controller;
+
+import com.kafka.springbootkafkatutorial.kafka.KafkaProducer;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/v1/kafka")
+public class KafkaController {
+
+   private KafkaProducer kafkaProducer;
+
+    public KafkaController(KafkaProducer kafkaProducer) {
+        this.kafkaProducer = kafkaProducer;
+    }
+    // http://localhost:8080/api/v1/kafka/publish?message=Hello World
+    @GetMapping("/publish")
+    public ResponseEntity<String> publishMessage(@RequestParam String message){
+        kafkaProducer.sendMessage(message);
+        return ResponseEntity.ok("Message sent to Topic");
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/kafka/KafkaConsumer.java

+package com.kafka.springbootkafkatutorial.kafka;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.stereotype.Service;
+
+@Service
+public class KafkaConsumer {
+
+    private static final Logger LOGGER= LoggerFactory.getLogger(KafkaConsumer.class);
+    @Value("${spring.kafka.topic.name}")
+    private String topicName;
+
+    @KafkaListener(topics = "${spring.kafka.topic.name}",groupId = "${spring.kafka.consumer.group_id}")
+    public void consumeMessage(String message){
+     LOGGER.info(String.format("Reaceived message from the Topic -> %s",message));
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/kafka/KafkaJsonConsumer.java

+package com.kafka.springbootkafkatutorial.kafka;
+
+import com.kafka.springbootkafkatutorial.payload.User;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.stereotype.Component;
+
+@Component
+public class KafkaJsonConsumer {
+    private static final Logger LOGGER= LoggerFactory.getLogger(KafkaJsonConsumer.class);
+
+    @KafkaListener(topics = "${spring.kafka.topic-json.name}",groupId ="${spring.kafka.consumer.group_id}")
+    public void consumeJsonMessage(User userData){
+        LOGGER.info(String.format("Json Message consumed -> %s",userData.toString()));
+
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/kafka/KafkaJsonProducer.java

+package com.kafka.springbootkafkatutorial.kafka;
+
+import com.kafka.springbootkafkatutorial.payload.User;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.kafka.support.KafkaHeaders;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.stereotype.Component;
+
+@Component
+public class KafkaJsonProducer {
+    private static final Logger LOGGER= LoggerFactory.getLogger(KafkaProducer.class);
+
+    @Value("${spring.kafka.topic-json.name}")
+    private String jsonTopicName;
+
+    private final KafkaTemplate<String,String> kafkaTemplate;
+
+    public KafkaJsonProducer(KafkaTemplate<String, String> kafkaTemplate) {
+        this.kafkaTemplate = kafkaTemplate;
+    }
+
+    public void sendMessage(User userData){
+        LOGGER.info(String.format("Message sent  ->%s",userData.toString()));
+
+        Message<User> message= MessageBuilder
+                .withPayload(userData)
+                .setHeader(KafkaHeaders.TOPIC,jsonTopicName)
+                .build();
+        kafkaTemplate.send(message);
+
+
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/kafka/KafkaProducer.java

+package com.kafka.springbootkafkatutorial.kafka;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.stereotype.Service;
+
+@Service
+public class KafkaProducer {
+    private static final Logger LOGGER= LoggerFactory.getLogger(KafkaProducer.class);
+
+    @Value("${spring.kafka.topic.name}")
+    private String topicName;
+
+    private KafkaTemplate<String,String> kafkaTemplate;
+
+    public KafkaProducer(KafkaTemplate<String, String> kafkaTemplate) {
+        this.kafkaTemplate = kafkaTemplate;
+    }
+
+    public void sendMessage(String message){
+        LOGGER.info(String.format("Message sent %s",message));
+        kafkaTemplate.send(topicName,message);
+    }
+}

src/main/java/com/kafka/springbootkafkatutorial/payload/User.java

+package com.kafka.springbootkafkatutorial.payload;
+
+public class User {
+    private int id;
+    private String firstName;
+    private String lastName;
+
+    public int getId() {
+        return id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" +
+                "id=" + id +
+                ", firstName='" + firstName + '\'' +
+                ", lastName='" + lastName + '\'' +
+                '}';
+    }
+
+
+
+}

src/main/resources/application.yml

+spring:
+  kafka:
+    consumer:
+      bootstrap-servers:
+        - localhost:9092
+      group-id: myGroup
+      auto-offset-reset: earliest
+      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
+      #value-deserializer: org.apache.kafka.common.serialization.StringDeserializer
+      value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
+      properties:
+        spring:
+          json:
+            trusted:
+              packages: "*"
+
+      group_id: myGroup
+
+
+    producer:
+      bootstrap-servers:
+        - localhost:9092
+      key-serializer: org.apache.kafka.common.serialization.StringSerializer
+      #value-serializer: org.apache.kafka.common.serialization.StringSerializer
+      value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
+
+    topic:
+      name: ExampleTopic
+    topic-json:
+      name: JsonTopic
\ No newline at end of file

src/test/java/com/kafka/springbootkafkatutorial/SpringbootKafkaTutorialApplicationTests.java

+package com.kafka.springbootkafkatutorial;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class SpringbootKafkaTutorialApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}