Upgrade Scala Version

2.13 is now the version recommended by Apache Kafka.

Author: garyrussell

build.gradle

@@ -61,7 +61,7 @@ ext {
 	micrometerVersion = '1.5.2'
 	mockitoVersion = '3.3.3'
 	reactorVersion = 'Dysprosium-SR9'
-	scalaVersion = '2.12'
+	scalaVersion = '2.13'
 	springDataCommonsVersion = '2.3.1.RELEASE'
 	springRetryVersion = '1.3.0'
 	springVersion = '5.2.7.RELEASE'

src/reference/asciidoc/appendix.adoc

@@ -1,9 +1,9 @@
-////
+[[update-deps]]
+== Override Spring Boot Dependencies
 
-[[deps-for-24x]]
-== Override Spring Boot Dependencies to use Spring for Apache Kafka 2.4
-
-When you use `spring-kafka-test` (version 2.4.x) with Spring Boot, you need to override certain Boot managed dependencies, as follows:
+When using Spring for Apache Kafka in a Spring Boot application, the Kafka dependency versions are determined by Spring Boot's dependency management.
+If you wish to use a different version, you need to override all of the associated dependencies.
+This is especially true when using the embedded Kafka broker in `spring-kafka-test`.
 
 **maven**
 
@@ -26,35 +26,35 @@ When you use `spring-kafka-test` (version 2.4.x) with Spring Boot, you need to o
 <dependency>
     <groupId>org.apache.kafka</groupId>
     <artifactId>kafka-clients</artifactId>
-    <version>2.4.1</version>
+    <version>{kafka-version}</version>
 </dependency>
 
 <!-- optional - only needed when using kafka-streams -->
 <dependency>
     <groupId>org.apache.kafka</groupId>
     <artifactId>kafka-streams</artifactId>
-    <version>2.4.1</version>
+    <version>{kafka-version}</version>
 </dependency>
 
 <dependency>
     <groupId>org.apache.kafka</groupId>
     <artifactId>kafka-clients</artifactId>
-    <version>2.4.1</version>
+    <version>{kafka-version}</version>
     <classifier>test</classifier>
     <scope>test</scope>
 </dependency>
 
 <dependency>
     <groupId>org.apache.kafka</groupId>
-    <artifactId>kafka_2.12</artifactId>
-    <version>2.4.1</version>
+    <artifactId>kafka_2.13</artifactId>
+    <version>{kafka-version}</version>
     <scope>test</scope>
 </dependency>
 
 <dependency>
     <groupId>org.apache.kafka</groupId>
-    <artifactId>kafka_2.12</artifactId>
-    <version>2.4.1</version>
+    <artifactId>kafka_2.13</artifactId>
+    <version>{kafka-version}</version>
     <classifier>test</classifier>
     <scope>test</scope>
 </dependency>
@@ -70,21 +70,18 @@ dependencies {
 
     implementation 'org.springframework.kafka:spring-kafka:{project-version}'
 
-    implementation 'org.apache.kafka:kafka-clients:2.4.1'
-    implementation 'org.apache.kafka:kafka-streams:2.4.1' // optional - only needed when using kafka-streams
-    testImplementation ('org.springframework.kafka:spring-kafka-test:{project-version}') {
-        exclude module: 'kafka_2.11'
-    }
-    testImplementation 'org.apache.kafka:kafka-clients:2.4.1:test'
-    testImplementation 'org.apache.kafka:kafka_2.12:2.4.1'
-    testImplementation 'org.apache.kafka:kafka_2.12:2.4.1:test'
+    implementation "org.apache.kafka:kafka-clients:$kafkaVersion"
+    implementation "org.apache.kafka:kafka-streams:$kafkaVersion" // optional - only needed when using kafka-streams
+    testImplementation 'org.springframework.kafka:spring-kafka-test:{project-version}'
+    testImplementation "org.apache.kafka:kafka-clients:$kafkaVersion:test"
+    testImplementation "org.apache.kafka:kafka_2.13:$kafkaVersion"
+    testImplementation "org.apache.kafka:kafka_2.13:$kafkaVersion:test"
 
 }
 ----
 ====
 
 The test scope dependencies are only needed if you are using the embedded Kafka broker in tests.
-////
 
 [appendix]
 [[history]]