feat: kafka and zookeeper

Author: keskiju

alternatives/server-micronaut-java/README.md

@@ -2,4 +2,4 @@
 
 ## Autorestart
 
-You can disable autorestart in `src/main/resources/application.yml` if you would rather restart manually with `taito restart:server`.
+You can turn autorestart on/off in `src/main/resources/application.yml`. Note that you can manually restart the server at anytime with `taito restart:server`.

alternatives/server-micronaut-java/bin/main/.gitignore

@@ -5,11 +5,12 @@ micronaut:
   io:
     watch:
       paths: src/main/java
-      restart: true
+      restart: false
 
 ---
 datasources:
   default:
+    # TODO: DATABASE_PORT
     url: jdbc:postgresql://${DATABASE_HOST}:5432/${DATABASE_NAME}
     username: ${DATABASE_USER}
     password: ${DATABASE_PASSWORD}
@@ -20,4 +21,7 @@ datasources:
 ---
 kafka:
   bootstrap:
-    servers: localhost:9092
+    servers: ${KAFKA_HOST}:${KAFKA_PORT}
+  producers:
+    default:
+      retries: 5

alternatives/server-micronaut-java/bin/main/application.yml

@@ -57,7 +57,9 @@ dependencies {
     testCompile "io.micronaut.test:micronaut-test-junit5"
     testRuntime "org.junit.jupiter:junit-jupiter-engine"
 
-    // Database and database class generation
+    compile "org.apache.commons:commons-lang3:3.9"
+
+    // Database, jooq, and jooq class generation
     compile 'io.micronaut:micronaut-spring' // For db transaction support
     runtime 'org.springframework:spring-jdbc' // For db transaction support
     compile 'org.jooq:jooq:3.11.11'
@@ -68,12 +70,10 @@ dependencies {
     generate 'org.jooq:jooq-codegen:3.11.11'
     generate 'org.postgresql:postgresql:42.2.5'
     runtime 'org.postgresql:postgresql:42.2.5'
-
     generate "javax.xml.bind:jaxb-api:2.3.0"
     generate "com.sun.xml.bind:jaxb-core:2.3.0"
     generate "com.sun.xml.bind:jaxb-impl:2.3.0"
     generate "javax.activation:activation:1.1.1"
-
 }
 
 test.classpath += configurations.developmentOnly

alternatives/server-micronaut-java/bin/test/.gitignore

@@ -5,4 +5,14 @@ public class Post {
   public String subject;
   public String content;
   public String author;
+  
+  public Post() {}
+  
+  public Post(String id, String subject, String content, String author) {
+    this.id = id;
+    this.subject = subject;
+    this.content = content;
+    this.author = author;
+  }
+  
 }

alternatives/server-micronaut-java/build.gradle

@@ -15,13 +15,16 @@ public class PostDAO {
   private @Inject DSLContext jooq;
 
   public List<Post> fetch() {
-    return jooq.selectFrom(POSTS).orderBy(POSTS.ID).fetchInto(Post.class);
+    return jooq.selectFrom(POSTS)
+      .orderBy(POSTS.CREATED_AT.desc())
+      .fetchInto(Post.class);
   }
 
   public Post create(Post post) {
-    jooq.insertInto(POSTS, POSTS.SUBJECT, POSTS.AUTHOR, POSTS.CONTENT).values(post.subject, post.author, post.content)
-        .returning(POSTS.ID, POSTS.SUBJECT, POSTS.AUTHOR, POSTS.CONTENT);
-    // .fetchOne().into(Post.class);
+    jooq.insertInto(POSTS, POSTS.SUBJECT, POSTS.AUTHOR, POSTS.CONTENT)
+      .values(post.subject, post.author, post.content)
+      .returning(POSTS.ID, POSTS.SUBJECT, POSTS.AUTHOR, POSTS.CONTENT)
+      .fetchOne().into(Post.class);
     return post;
   }
 

alternatives/server-micronaut-java/src/main/java/content/Post.java

@@ -1,12 +1,12 @@
 package content;
 
+import io.micronaut.spring.tx.annotation.Transactional;
+
 import java.util.List;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
-// import io.micronaut.spring.tx.annotation.Transactional;
-
 @Singleton
 public class PostService {
 
@@ -17,7 +17,10 @@ public List<Post> fetch() {
     return postDAO.fetch();
   }
 
-  // @Transactional
+  // TODO: @Transactional does not work properly?
+  // package org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy
+  // not in classpath?
+  @Transactional
   public Post create(Post post) {
     return postDAO.create(post);
   }

alternatives/server-micronaut-java/src/main/java/content/PostDAO.java

@@ -0,0 +1,22 @@
+package content;
+
+import javax.inject.Inject;
+
+import io.micronaut.configuration.kafka.annotation.KafkaKey;
+import io.micronaut.configuration.kafka.annotation.KafkaListener;
+import io.micronaut.configuration.kafka.annotation.OffsetReset;
+import io.micronaut.configuration.kafka.annotation.Topic;
+
+@KafkaListener(offsetReset = OffsetReset.EARLIEST)
+public class UserListener {
+
+  @Inject
+  PostService postService;
+
+  @Topic("users")
+  public void receive(@KafkaKey String id, String username) {
+    postService.create(new Post(null, "User " + username + " was added!",
+        "Let's make him/her feel welcome", "System"));
+  }
+
+}