Fix some Kotlin <-> Java DSL interoperability

* Remove generic argument from the `EnricherSpec.property()` which simply does nothing, but noise
- `Object` is enough
* Do the same for `EnricherSpec.header()`
* Fix `KotlinEnricherSpec`, respectively: no generic argument - just `Any`
* Make `KotlinIntegrationFlowDefinition.route()` to expect non-null for `router` arg
* Add `& Any` to generic params of the `KotlinRouterSpec` methods - according compiler warning requirements

spring-integration-core/src/main/java/org/springframework/integration/dsl/EnricherSpec.java

@@ -182,11 +182,10 @@ public EnricherSpec shouldClonePayload(boolean shouldClonePayload) {
 	/**
 	 * @param key the key.
 	 * @param value the value.
-	 * @param <V> the value type.
 	 * @return the enricher spec.
 	 * @see ContentEnricher#setPropertyExpressions(Map)
 	 */
-	public <V> EnricherSpec property(String key, V value) {
+	public EnricherSpec property(String key, Object value) {
 		this.propertyExpressions.put(key, new ValueExpression<>(value));
 		return _this();
 	}
@@ -220,25 +219,23 @@ public <P> EnricherSpec propertyFunction(String key, Function<Message<P>, Object
 	 * Set a header with the value if it is not already present.
 	 * @param name the header name.
 	 * @param value the value.
-	 * @param <V> the value type.
 	 * @return the enricher spec.
 	 * @see ContentEnricher#setHeaderExpressions(Map)
 	 */
-	public <V> EnricherSpec header(String name, V value) {
+	public EnricherSpec header(String name, Object value) {
 		return header(name, value, null);
 	}
 
 	/**
 	 * @param name the header name.
 	 * @param value the value.
 	 * @param overwrite true to overwrite the header if already present.
-	 * @param <V> the value type.
 	 * @return the enricher spec.
 	 * @see ContentEnricher#setHeaderExpressions(Map)
 	 */
-	public <V> EnricherSpec header(String name, V value, @Nullable Boolean overwrite) {
-		AbstractHeaderValueMessageProcessor<V> headerValueMessageProcessor =
-				new StaticHeaderValueMessageProcessor<V>(value);
+	public EnricherSpec header(String name, Object value, @Nullable Boolean overwrite) {
+		AbstractHeaderValueMessageProcessor<Object> headerValueMessageProcessor =
+				new StaticHeaderValueMessageProcessor<>(value);
 		headerValueMessageProcessor.setOverwrite(overwrite);
 		return header(name, headerValueMessageProcessor);
 	}
@@ -305,11 +302,10 @@ private EnricherSpec headerExpression(String name, Expression expression, @Nulla
 	 * Set a header value using an explicit {@link HeaderValueMessageProcessor}.
 	 * @param headerName the header name.
 	 * @param headerValueMessageProcessor the headerValueMessageProcessor.
-	 * @param <V> the value type.
 	 * @return the enricher spec.
 	 * @see ContentEnricher#setHeaderExpressions(Map)
 	 */
-	public <V> EnricherSpec header(String headerName, HeaderValueMessageProcessor<V> headerValueMessageProcessor) {
+	public EnricherSpec header(String headerName, HeaderValueMessageProcessor<Object> headerValueMessageProcessor) {
 		Assert.hasText(headerName, "'headerName' must not be empty");
 		this.headerExpressions.put(headerName, headerValueMessageProcessor);
 		return _this();

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

@@ -85,7 +85,7 @@ class KotlinEnricherSpec(override val delegate: EnricherSpec)
 		this.delegate.shouldClonePayload(shouldClonePayload)
 	}
 
-	fun <V> property(key: String, value: V) {
+	fun property(key: String, value: Any) {
 		this.delegate.property(key, value)
 	}
 
@@ -97,7 +97,7 @@ class KotlinEnricherSpec(override val delegate: EnricherSpec)
 		this.delegate.propertyFunction(key, function)
 	}
 
-	fun <V> header(name: String, value: V, overwrite: Boolean?) {
+	fun header(name: String, value: Any, overwrite: Boolean?) {
 		this.delegate.header(name, value, overwrite)
 	}
 
@@ -109,7 +109,7 @@ class KotlinEnricherSpec(override val delegate: EnricherSpec)
 		this.delegate.header(name, function, overwrite)
 	}
 
-	fun <V> header(headerName: String, headerValueMessageProcessor: HeaderValueMessageProcessor<V>) {
+	fun header(headerName: String, headerValueMessageProcessor: HeaderValueMessageProcessor<Any>) {
 		this.delegate.header(headerName, headerValueMessageProcessor)
 	}
 

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

@@ -1043,7 +1043,7 @@ class KotlinIntegrationFlowDefinition(@PublishedApi internal val delegate: Integ
 	 * current integration flow position.
 	 * In addition, accept options for the integration endpoint using [GenericEndpointSpec].
 	 */
-	fun <R : AbstractMessageRouter?> route(router: R, endpointConfigurer: GenericEndpointSpec<R>.() -> Unit = {}) {
+	fun <R : AbstractMessageRouter> route(router: R, endpointConfigurer: GenericEndpointSpec<R>.() -> Unit = {}) {
 		this.delegate.route(router, endpointConfigurer)
 	}
 

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

@@ -51,19 +51,19 @@ class KotlinRouterSpec<K, R : AbstractMappingMessageRouter>(override val delegat
 		this.delegate.channelKeyFallback(channelKeyFallback)
 	}
 
-	fun channelMapping(key: K, channelName: String) {
+	fun channelMapping(key: K & Any, channelName: String) {
 		this.delegate.channelMapping(key, channelName)
 	}
 
-	fun channelMapping(key: K, channel: MessageChannel) {
+	fun channelMapping(key: K & Any, channel: MessageChannel) {
 		this.delegate.channelMapping(key, channel)
 	}
 
-	fun subFlowMapping(key: K, subFlow: KotlinIntegrationFlowDefinition.() -> Unit) {
+	fun subFlowMapping(key: K & Any, subFlow: KotlinIntegrationFlowDefinition.() -> Unit) {
 		subFlowMapping(key) { definition -> subFlow(KotlinIntegrationFlowDefinition(definition)) }
 	}
 
-	fun subFlowMapping(key: K, subFlow: IntegrationFlow) {
+	fun subFlowMapping(key: K & Any, subFlow: IntegrationFlow) {
 		this.delegate.subFlowMapping(key, subFlow)
 	}