Merge pull request #6 from ralf-ueberfuhr-ars/feature/layers

add blogpost initialization

src/main/java/de/sample/schulung/spring/blog/domain/BlogPostInitializer.java

@@ -0,0 +1,28 @@
+package de.sample.schulung.spring.blog.domain;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class BlogPostInitializer {
+
+  private final BlogPostService service;
+
+  @EventListener(ContextRefreshedEvent.class)
+  void initBlogPosts() {
+    if(service.count() == 0) {
+      service.create(
+        BlogPost
+          .builder()
+          .title("Welcome to the blog!")
+          .content("This is a great blog :)")
+          .build()
+      );
+    }
+
+  }
+
+}

src/main/java/de/sample/schulung/spring/blog/domain/BlogPostService.java

@@ -18,6 +18,10 @@ public class BlogPostService {
 
   private final Map<UUID, BlogPost> blogPosts = new HashMap<>();
 
+  public long count() {
+    return blogPosts.size();
+  }
+
   public Stream<BlogPost> findAll() {
     return blogPosts.values().stream();
   }

src/test/java/de/sample/schulung/spring/blog/domain/BlogPostServiceTests.java

@@ -0,0 +1,23 @@
+package de.sample.schulung.spring.blog.domain;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+public class BlogPostServiceTests {
+
+  @Autowired
+  BlogPostService service;
+
+  @Test
+  void shouldNotBeEmpty() {
+    assertThat(service.count())
+      .isGreaterThan(0L);
+    assertThat(service.findAll())
+      .hasAtLeastOneElementOfType(BlogPost.class);
+  }
+
+}