feat(transactions): implementar módulo de transacciones con antifraude, persistencia y mensajería Kafka

anti-fraud-service/pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+ <groupId>com.yape</groupId>
+ <artifactId>anti-fraud-service</artifactId>
+ <version>1.0.0</version>
+
+ <properties>
+   <java.version>21</java.version>
+   <spring.boot.version>3.2.1</spring.boot.version>
+ </properties>
+
+ <dependencyManagement>
+   <dependencies>
+     <dependency>
+       <groupId>org.springframework.boot</groupId>
+       <artifactId>spring-boot-dependencies</artifactId>
+       <version>${spring.boot.version}</version>
+       <type>pom</type>
+       <scope>import</scope>
+     </dependency>
+   </dependencies>
+ </dependencyManagement>
+
+ <dependencies>
+   <dependency>
+     <groupId>org.springframework.boot</groupId>
+     <artifactId>spring-boot-starter-web</artifactId>
+   </dependency>
+   <dependency>
+     <groupId>org.springframework.boot</groupId>
+     <artifactId>spring-boot-starter-data-jpa</artifactId>
+   </dependency>
+   <dependency>
+     <groupId>org.springframework.kafka</groupId>
+     <artifactId>spring-kafka</artifactId>
+   </dependency>
+   <dependency>
+     <groupId>com.h2database</groupId>
+     <artifactId>h2</artifactId>
+     <scope>runtime</scope>
+   </dependency>
+
+     <dependency>
+         <groupId>org.springframework.boot</groupId>
+         <artifactId>spring-boot-starter-test</artifactId>
+         <scope>test</scope>
+     </dependency>
+     <dependency>
+         <groupId>org.mockito</groupId>
+         <artifactId>mockito-core</artifactId>
+         <scope>test</scope>
+     </dependency>
+     <dependency>
+         <groupId>org.mockito</groupId>
+         <artifactId>mockito-junit-jupiter</artifactId>
+         <scope>test</scope>
+     </dependency>
+     <dependency>
+         <groupId>org.projectlombok</groupId>
+         <artifactId>lombok</artifactId>
+         <scope>provided</scope>
+     </dependency>
+ </dependencies>
+
+ <build>
+   <plugins>
+     <plugin>
+       <groupId>org.springframework.boot</groupId>
+       <artifactId>spring-boot-maven-plugin</artifactId>
+     </plugin>
+       <plugin>
+           <groupId>org.apache.maven.plugins</groupId>
+           <artifactId>maven-compiler-plugin</artifactId>
+           <configuration>
+               <source>21</source>
+               <target>21</target>
+           </configuration>
+       </plugin>
+   </plugins>
+ </build>
+</project>

anti-fraud-service/src/main/java/com/yape/antifraud/AntiFraudApplication.java

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

anti-fraud-service/src/main/java/com/yape/antifraud/aplication/FraudDecisionService.java

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+package com.yape.antifraud.aplication;
+
+import com.yape.antifraud.kafka.models.TransactionReqEvent;
+
+public interface FraudDecisionService {
+
+  void analyze(TransactionReqEvent transaction);
+}

anti-fraud-service/src/main/java/com/yape/antifraud/aplication/ProducerService.java

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+package com.yape.antifraud.aplication;
+
+import com.yape.antifraud.kafka.models.TransactionRespEvent;
+
+public interface ProducerService {
+
+  void sendMessage(TransactionRespEvent transaction);
+}

anti-fraud-service/src/main/java/com/yape/antifraud/aplication/impl/FraudDetectionService.java

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+package com.yape.antifraud.aplication.impl;
+
+import com.yape.antifraud.kafka.models.TransactionRespEvent;
+import com.yape.antifraud.model.TransactionStatus;
+import com.yape.antifraud.kafka.models.TransactionReqEvent;
+import com.yape.antifraud.aplication.FraudDecisionService;
+import com.yape.antifraud.aplication.ProducerService;
+import org.springframework.stereotype.Service;
+
+@Service
+public class FraudDetectionService implements FraudDecisionService {
+
+  private final FraudPolicy fraudPolicy;
+  private final ProducerService producer;
+
+  public FraudDetectionService(FraudPolicy fraudPolicy, ProducerService producer){
+    this.fraudPolicy = fraudPolicy;
+    this.producer = producer;
+  }
+
+  @Override
+  public void analyze(TransactionReqEvent transaction) {
+
+    var isFraud = fraudPolicy.isFraud(transaction.getAmount());
+    var statusTrx = isFraud? TransactionStatus.REJECTED : TransactionStatus.APPROVED;
+    transaction.setStatus(statusTrx);
+
+    var updateTransaction = getUpdateEvent(transaction);
+    producer.sendMessage(updateTransaction);
+  }
+
+  private TransactionRespEvent getUpdateEvent(TransactionReqEvent transaction){
+    return new TransactionRespEvent(transaction.getId(), transaction.getStatus());
+  }
+}

anti-fraud-service/src/main/java/com/yape/antifraud/aplication/impl/FraudPolicy.java

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+package com.yape.antifraud.aplication.impl;
+
+import org.springframework.stereotype.Component;
+import static com.yape.antifraud.utils.Constants.MAX_ALLOWED_VALUE;
+
+@Component
+public class FraudPolicy {
+
+  public boolean isFraud(double amount) {
+    return amount > MAX_ALLOWED_VALUE;
+  }
+}

anti-fraud-service/src/main/java/com/yape/antifraud/kafka/config/KafkaConfig.java

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+package com.yape.antifraud.kafka.config;
+
+import java.util.HashMap;
+import java.util.Map;
+import com.yape.antifraud.kafka.models.TransactionReqEvent;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.kafka.annotation.EnableKafka;
+import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
+import org.springframework.kafka.core.*;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
+import org.springframework.kafka.support.serializer.JsonSerializer;
+
+import static com.yape.antifraud.utils.Constants.TOPIC_SERVICE_GROUP;
+
+
+@EnableKafka
+@Configuration
+public class KafkaConfig {
+
+  @Value("${spring.kafka.bootstrap-servers}")
+  private String bootstrapServers;
+
+  @Bean
+  public ProducerFactory<String, Object> producerFactory() {
+    Map<String, Object> props = new HashMap<>();
+    props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
+    props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
+    props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);
+    props.put(JsonSerializer.ADD_TYPE_INFO_HEADERS, false);
+    return new DefaultKafkaProducerFactory<>(props);
+  }
+
+  @Bean
+  public KafkaTemplate<String, Object> kafkaTemplate() {
+    return new KafkaTemplate<>(producerFactory());
+  }
+
+  @Bean
+  public ConsumerFactory<String, TransactionReqEvent> consumerFactory() {
+
+    JsonDeserializer<TransactionReqEvent> deserializer = new JsonDeserializer<>(TransactionReqEvent.class);
+    deserializer.addTrustedPackages("*");
+    deserializer.setRemoveTypeHeaders(true);
+
+    Map<String, Object> props = new HashMap<>();
+    props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
+    props.put(ConsumerConfig.GROUP_ID_CONFIG, TOPIC_SERVICE_GROUP);//"anti-fraud-group"
+    props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "latest");
+    return new DefaultKafkaConsumerFactory<>(props, new StringDeserializer(), deserializer);
+  }
+
+  @Bean
+  public ConcurrentKafkaListenerContainerFactory<String, TransactionReqEvent> kafkaListenerContainerFactory() {
+
+    ConcurrentKafkaListenerContainerFactory<String, TransactionReqEvent> factory = new ConcurrentKafkaListenerContainerFactory<>();
+    factory.setConsumerFactory(consumerFactory());
+    return factory;
+  }
+}

anti-fraud-service/src/main/java/com/yape/antifraud/kafka/event/TransactionConsumer.java

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+package com.yape.antifraud.kafka.event;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import com.yape.antifraud.model.TransactionStatus;
+import com.yape.antifraud.aplication.impl.FraudDetectionService;
+import com.yape.antifraud.aplication.FraudDecisionService;
+import com.yape.antifraud.kafka.models.TransactionReqEvent;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.stereotype.Component;
+
+import static com.yape.antifraud.utils.Constants.TOPIC_CREATED;
+import static com.yape.antifraud.utils.Constants.TOPIC_SERVICE_GROUP;
+
+@Component
+public class TransactionConsumer {
+
+  private static final Logger log = LoggerFactory.getLogger(TransactionConsumer.class);
+  private final FraudDecisionService fraudService;
+
+  public TransactionConsumer(FraudDetectionService fraudService) {
+    this.fraudService = fraudService;
+  }
+
+  @KafkaListener(topics = TOPIC_CREATED, groupId = TOPIC_SERVICE_GROUP)
+  public void consume(TransactionReqEvent transaction) {
+
+    fraudService.analyze(transaction);
+    log.info("📦 [ANTI-FRAUD-SERVICE LISTENER] {} -> {} {}", transaction.getId(), transaction.getStatus(), transaction.getStatus() == TransactionStatus.APPROVED ? "✅" : transaction.getStatus() == TransactionStatus.REJECTED ? "❌" : "⏳");
+  }
+}

anti-fraud-service/src/main/java/com/yape/antifraud/kafka/event/TransactionProducer.java

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+package com.yape.antifraud.kafka.event;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import com.yape.antifraud.aplication.ProducerService;
+import com.yape.antifraud.kafka.models.TransactionRespEvent;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.stereotype.Component;
+
+import static com.yape.antifraud.utils.Constants.TOPIC_UPDATE;
+
+
+@Component
+public class TransactionProducer implements ProducerService {
+
+  private static final Logger log = LoggerFactory.getLogger(TransactionProducer.class);
+  private final KafkaTemplate<String, Object> kafkaTemplate;
+
+  public TransactionProducer(KafkaTemplate<String, Object> kafkaTemplate) {
+    this.kafkaTemplate = kafkaTemplate;
+  }
+
+  @Override
+  public void sendMessage(TransactionRespEvent transaction) {
+
+    kafkaTemplate.send(TOPIC_UPDATE, transaction);
+    log.info("📦 [ANTI-FRAUD-SERVICE PRODUCER] {} -> {}", transaction.id(), transaction.status());
+  }
+}