Add handle() based on single argument lambda

* Upgrade dependencies including Gradle

spring-integration-kotlin-dsl/build.gradle

@@ -4,7 +4,7 @@ plugins {
     id 'idea'
     id 'jacoco'
     id 'org.sonarqube' version '2.8'
-    id 'io.spring.dependency-management' version '1.0.8.RELEASE'
+    id 'io.spring.dependency-management' version '1.0.9.RELEASE'
     id 'org.jetbrains.kotlin.jvm' version "$kotlinVersion"
     id 'org.jetbrains.kotlin.plugin.spring' version "$kotlinVersion"
     id 'org.jetbrains.dokka' version '0.9.18'
@@ -28,10 +28,10 @@ repositories {
 ext {
     assertkVersion = '0.20'
     jacksonVersion = '2.10.1'
-    junitVersion = '5.5.2'
+    junitVersion = '5.6.0'
     log4jVersion = '2.13.0'
-    reactorVersion = 'Dysprosium-SR1'
-    springIntegrationVersion = '5.2.2.RELEASE'
+    reactorVersion = 'Dysprosium-SR4'
+    springIntegrationVersion = '5.2.3.RELEASE'
 
     idPrefix = 'kotlin-dsl'
 
@@ -66,13 +66,11 @@ dependencyManagement {
 compileKotlin {
     kotlinOptions {
         jvmTarget = '1.8'
-        freeCompilerArgs = ['-Xjsr305=strict']
         allWarningsAsErrors = true
     }
 }
 compileTestKotlin {
     kotlinOptions {
-        freeCompilerArgs = ['-Xjsr305=strict']
         jvmTarget = '1.8'
     }
 }
@@ -82,7 +80,7 @@ eclipse.project.natures += 'org.springframework.ide.eclipse.core.springnature'
 
 
 jacoco {
-    toolVersion = '0.8.4'
+    toolVersion = '0.8.5'
 }
 
 dependencies {

spring-integration-kotlin-dsl/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

spring-integration-kotlin-dsl/src/main/kotlin/org/springframework/integration/dsl/kotlin/KotlinIntegrationFlowDefinition.kt

@@ -485,6 +485,25 @@ class KotlinIntegrationFlowDefinition(@PublishedApi internal val delegate: Integ
 		this.delegate.handle(messageHandlerSpec, endpointConfigurer)
 	}
 
+	/**
+	 * Populate a [ServiceActivatingHandler] for the provided
+	 * [MessageHandler] lambda.
+	 */
+	fun handle(messageHandler: (Message<*>) -> Unit) {
+		this.delegate.handle(MessageHandler { messageHandler(it) })
+	}
+
+	/**
+	 * Populate a [ServiceActivatingHandler] for the provided
+	 * [MessageHandler] lambda.
+	 * In addition accept options for the integration endpoint using [GenericEndpointSpec].
+	 */
+	fun handle(messageHandler: (Message<*>) -> Unit,
+			   endpointConfigurer: GenericEndpointSpec<MessageHandler>.() -> Unit) {
+
+		this.delegate.handle(MessageHandler { messageHandler(it) }, endpointConfigurer)
+	}
+
 	/**
 	 * Populate a [ServiceActivatingHandler] for the provided
 	 * [MessageHandler] implementation.

spring-integration-kotlin-dsl/src/test/kotlin/org/springframework/integration/dsl/kotlin/test/KotlinDslTests.kt

@@ -222,6 +222,7 @@ class KotlinDslTests {
 				integrationFlow("convertFlowInput") {
 					convert<TestPojo>()
 					convert<TestPojo> { id("kotlinConverter") }
+					handle { m -> (m.headers[MessageHeaders.REPLY_CHANNEL] as MessageChannel).send(m) }
 				}
 
 		@Bean
@@ -231,7 +232,10 @@ class KotlinDslTests {
 					split<Message<*>> { it.payload }
 					split<String>({ it }) { id("splitterEndpoint") }
 					resequence()
-					aggregate { id("aggregator").outputProcessor { it.one } }
+					aggregate {
+						id("aggregator")
+						outputProcessor { it.one }
+					}
 				}
 
 		@Bean