Add Statistics Provider Service

pom.xml

@@ -10,6 +10,7 @@
 
   <modules>
     <module>account-service-provider</module>
+    <module>statistics-service-provider</module>
   </modules>
 
 </project>

statistics-service-provider/pom.xml

@@ -0,0 +1,108 @@
+<?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>3.3.0</version>
+    <relativePath/> <!-- lookup parent from repository -->
+  </parent>
+  <groupId>de.sample.schulung.spring</groupId>
+  <artifactId>statistics-service-provider</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <name>Statistics Service Provider</name>
+  <properties>
+    <java.version>17</java.version>
+    <mapstruct.version>1.5.5.Final</mapstruct.version>
+    <lombok-mapstruct-binding.version>0.2.0</lombok-mapstruct-binding.version>
+  </properties>
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-validation</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-devtools</artifactId>
+      <scope>runtime</scope>
+      <optional>true</optional>
+    </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <optional>true</optional>
+    </dependency>
+    <dependency>
+      <groupId>org.mapstruct</groupId>
+      <artifactId>mapstruct</artifactId>
+      <version>${mapstruct.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-data-jpa</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.h2database</groupId>
+      <artifactId>h2</artifactId>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <configuration>
+            <annotationProcessorPaths>
+              <path>
+                <groupId>org.projectlombok</groupId>
+                <artifactId>lombok</artifactId>
+                <version>${lombok.version}</version>
+              </path>
+              <path>
+                <groupId>org.mapstruct</groupId>
+                <artifactId>mapstruct-processor</artifactId>
+                <version>${mapstruct.version}</version>
+              </path>
+              <path>
+                <groupId>org.projectlombok</groupId>
+                <artifactId>lombok-mapstruct-binding</artifactId>
+                <version>${lombok-mapstruct-binding.version}</version>
+              </path>
+            </annotationProcessorPaths>
+          </configuration>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+        <configuration>
+          <excludes>
+            <exclude>
+              <groupId>org.projectlombok</groupId>
+              <artifactId>lombok</artifactId>
+            </exclude>
+            <exclude>
+              <groupId>org.mapstruct</groupId>
+              <artifactId>mapstruct</artifactId>
+            </exclude>
+          </excludes>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

statistics-service-provider/src/main/java/de/sample/schulung/statistics/StatisticsServiceProviderApplication.java

@@ -0,0 +1,13 @@
+package de.sample.schulung.statistics;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class StatisticsServiceProviderApplication {
+
+  public static void main(String[] args) {
+    SpringApplication.run(StatisticsServiceProviderApplication.class, args);
+  }
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/boundary/CustomerStatisticsDto.java

@@ -0,0 +1,14 @@
+package de.sample.schulung.statistics.boundary;
+
+import lombok.Data;
+
+import java.time.LocalDate;
+
+@Data
+public class CustomerStatisticsDto {
+
+  private long count;
+  private LocalDate earliestBirthdate;
+  private LocalDate latestBirthdate;
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/boundary/CustomerStatisticsDtoMapper.java

@@ -0,0 +1,11 @@
+package de.sample.schulung.statistics.boundary;
+
+import de.sample.schulung.statistics.domain.CustomerStatistics;
+import org.mapstruct.Mapper;
+
+@Mapper(componentModel = "spring")
+public interface CustomerStatisticsDtoMapper {
+
+  CustomerStatisticsDto map(CustomerStatistics source);
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/boundary/StatisticsController.java

@@ -0,0 +1,31 @@
+package de.sample.schulung.statistics.boundary;
+
+import de.sample.schulung.statistics.domain.CustomerStatisticsService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/v1/statistics")
+@RequiredArgsConstructor
+public class StatisticsController {
+
+  private final CustomerStatisticsService customerStatisticsService;
+  private final CustomerStatisticsDtoMapper customerStatisticsDtoMapper;
+
+  @GetMapping(
+    value = "/customers",
+    produces = MediaType.APPLICATION_JSON_VALUE
+  )
+  public CustomerStatisticsDto getStatistics() {
+    return this.customerStatisticsDtoMapper
+      .map(
+        this.customerStatisticsService
+          .getStatistics()
+      );
+  }
+
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/Customer.java

@@ -0,0 +1,20 @@
+package de.sample.schulung.statistics.domain;
+
+import jakarta.validation.constraints.NotNull;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDate;
+import java.util.UUID;
+
+@Getter
+@Setter
+@Builder
+public class Customer {
+
+  @NotNull
+  private UUID uuid;
+  private LocalDate dateOfBirth;
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomerStatistics.java

@@ -0,0 +1,17 @@
+package de.sample.schulung.statistics.domain;
+
+import lombok.Builder;
+import lombok.Data;
+
+import java.time.LocalDate;
+
+@Data
+@Builder
+public class CustomerStatistics {
+
+  @Builder.Default
+  private long count = 0;
+  private LocalDate earliestBirthdate;
+  private LocalDate latestBirthdate;
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomerStatisticsService.java

@@ -0,0 +1,16 @@
+package de.sample.schulung.statistics.domain;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class CustomerStatisticsService {
+
+  private final CustomerStatisticsSink customerStatisticsSink;
+
+  public CustomerStatistics getStatistics() {
+    return customerStatisticsSink.getStatistics();
+  }
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomerStatisticsSink.java

@@ -0,0 +1,7 @@
+package de.sample.schulung.statistics.domain;
+
+public interface CustomerStatisticsSink {
+
+  CustomerStatistics getStatistics();
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomersInitializer.java

@@ -0,0 +1,40 @@
+package de.sample.schulung.statistics.domain;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+import java.time.LocalDate;
+import java.util.UUID;
+
+@Component
+@ConditionalOnProperty(
+  name = "application.init-sample-data.enabled",
+  havingValue = "true"
+)
+@RequiredArgsConstructor
+public class CustomersInitializer {
+
+  private final CustomersService customersService;
+
+  @EventListener(ContextRefreshedEvent.class)
+  public void createSamples() {
+    if (customersService.count() < 1) {
+      customersService.saveCustomer(
+        Customer.builder()
+          .uuid(UUID.randomUUID())
+          .dateOfBirth(LocalDate.now().minusYears(20).minusDays(100))
+          .build()
+      );
+      customersService.saveCustomer(
+        Customer.builder()
+          .uuid(UUID.randomUUID())
+          .dateOfBirth(LocalDate.now().minusYears(30).minusDays(55))
+          .build()
+      );
+    }
+  }
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomersService.java

@@ -0,0 +1,28 @@
+package de.sample.schulung.statistics.domain;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.validation.annotation.Validated;
+
+import java.util.UUID;
+
+@Validated
+@Service
+@RequiredArgsConstructor
+public class CustomersService {
+
+  private final CustomersSink customersSink;
+
+  public void saveCustomer(Customer customer) {
+    customersSink.saveCustomer(customer);
+  }
+
+  public void deleteCustomer(UUID uuid) {
+    customersSink.deleteCustomer(uuid);
+  }
+
+  public long count() {
+    return customersSink.count();
+  }
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/domain/CustomersSink.java

@@ -0,0 +1,11 @@
+package de.sample.schulung.statistics.domain;
+
+import java.util.UUID;
+
+public interface CustomersSink {
+
+  void saveCustomer(Customer customer);
+  void deleteCustomer(UUID uuid);
+  long count();
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/persistence/CustomerEntity.java

@@ -0,0 +1,24 @@
+package de.sample.schulung.statistics.persistence;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import jakarta.validation.constraints.NotNull;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDate;
+import java.util.UUID;
+
+@Getter
+@Setter
+@Entity(name = "Customer")
+@Table(name = "CUSTOMERS")
+public class CustomerEntity {
+
+  @NotNull
+  @Id
+  private UUID uuid;
+  private LocalDate dateOfBirth;
+
+}

statistics-service-provider/src/main/java/de/sample/schulung/statistics/persistence/CustomerEntityMapper.java

@@ -0,0 +1,11 @@
+package de.sample.schulung.statistics.persistence;
+
+import de.sample.schulung.statistics.domain.Customer;
+import org.mapstruct.Mapper;
+
+@Mapper(componentModel = "spring")
+public interface CustomerEntityMapper {
+
+  CustomerEntity map(Customer customer);
+
+}