Remove @MessagingGateway usage

The `@MessagingGateway` requires a classpath scanning which is not possible
when we use these function artifacts as dependencies, where packages are fully
different from what target project is built with

consumer/spring-cassandra-consumer/src/main/java/org/springframework/cloud/fn/consumer/cassandra/CassandraConsumerConfiguration.java

@@ -47,9 +47,9 @@ import org.springframework.data.cassandra.core.UpdateOptions;
 import org.springframework.data.cassandra.core.WriteResult;
 import org.springframework.data.cassandra.core.cql.WriteOptions;
 import org.springframework.integration.JavaUtils;
-import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.cassandra.outbound.CassandraMessageHandler;
 import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.gateway.AnnotationGatewayProxyFactoryBean;
 import org.springframework.integration.support.json.Jackson2JsonObjectMapper;
 import org.springframework.integration.transformer.AbstractPayloadTransformer;
 import org.springframework.messaging.MessageHandler;
@@ -71,7 +71,7 @@ public class CassandraConsumerConfiguration {
 	private CassandraConsumerProperties cassandraSinkProperties;
 
 	@Bean
-	public Consumer<Object> cassandraConsumer(CassandraConsumerFunction cassandraConsumerFunction) {
+	Consumer<Object> cassandraConsumer(CassandraConsumerFunction cassandraConsumerFunction) {
 		return (payload) -> cassandraConsumerFunction.apply(payload).block();
 	}
 
@@ -121,6 +121,13 @@ public class CassandraConsumerConfiguration {
 		return cassandraMessageHandler;
 	}
 
+	@Bean
+	AnnotationGatewayProxyFactoryBean<CassandraConsumerFunction> cassandraConsumerFunction() {
+		var gatewayProxyFactoryBean = new AnnotationGatewayProxyFactoryBean<>(CassandraConsumerFunction.class);
+		gatewayProxyFactoryBean.setDefaultRequestChannelName("cassandraConsumerFlow.input");
+		return gatewayProxyFactoryBean;
+	}
+
 	private static boolean isUuid(String uuid) {
 		if (uuid.length() == 36) {
 			String[] parts = uuid.split("-");
@@ -198,7 +205,6 @@ public class CassandraConsumerConfiguration {
 
 	}
 
-	@MessagingGateway(name = "cassandraConsumerFunction", defaultRequestChannel = "cassandraConsumerFlow.input")
 	interface CassandraConsumerFunction extends Function<Object, Mono<? extends WriteResult>> {
 
 	}

consumer/spring-elasticsearch-consumer/src/main/java/org/springframework/cloud/fn/consumer/elasticsearch/ElasticsearchConsumerConfiguration.java

@@ -45,10 +45,10 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.context.annotation.Bean;
 import org.springframework.integration.aggregator.AbstractAggregatingMessageGroupProcessor;
 import org.springframework.integration.aggregator.MessageCountReleaseStrategy;
-import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.config.AggregatorFactoryBean;
 import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.expression.ValueExpression;
+import org.springframework.integration.gateway.AnnotationGatewayProxyFactoryBean;
 import org.springframework.integration.store.MessageGroup;
 import org.springframework.integration.store.MessageGroupStore;
 import org.springframework.integration.store.SimpleMessageStore;
@@ -138,6 +138,14 @@ public class ElasticsearchConsumerConfiguration {
 		};
 	}
 
+	@Bean
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	AnnotationGatewayProxyFactoryBean<Consumer<Message<?>>> elasticsearchConsumer() {
+		var gatewayProxyFactoryBean = new AnnotationGatewayProxyFactoryBean<>(Consumer.class);
+		gatewayProxyFactoryBean.setDefaultRequestChannelName("elasticsearchConsumerFlow.input");
+		return (AnnotationGatewayProxyFactoryBean) gatewayProxyFactoryBean;
+	}
+
 	@Bean
 	public MessageHandler indexingHandler(ElasticsearchClient elasticsearchClient,
 			ElasticsearchConsumerProperties consumerProperties) {
@@ -303,9 +311,4 @@ public class ElasticsearchConsumerConfiguration {
 
 	}
 
-	@MessagingGateway(name = "elasticsearchConsumer", defaultRequestChannel = "elasticsearchConsumerFlow.input")
-	private interface MessageConsumer extends Consumer<Message<?>> {
-
-	}
-
 }

consumer/spring-jdbc-consumer/src/main/java/org/springframework/cloud/fn/consumer/jdbc/JdbcConsumerConfiguration.java

@@ -44,11 +44,11 @@ import org.springframework.expression.spel.SpelParseException;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.integration.aggregator.DefaultAggregatingMessageGroupProcessor;
 import org.springframework.integration.aggregator.MessageCountReleaseStrategy;
-import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.config.AggregatorFactoryBean;
 import org.springframework.integration.context.IntegrationContextUtils;
 import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.expression.ValueExpression;
+import org.springframework.integration.gateway.AnnotationGatewayProxyFactoryBean;
 import org.springframework.integration.jdbc.JdbcMessageHandler;
 import org.springframework.integration.jdbc.SqlParameterSourceFactory;
 import org.springframework.integration.store.MessageGroupStore;
@@ -131,6 +131,14 @@ public class JdbcConsumerConfiguration {
 		};
 	}
 
+	@Bean
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	AnnotationGatewayProxyFactoryBean<Consumer<Message<?>>> jdbcConsumer() {
+		var gatewayProxyFactoryBean = new AnnotationGatewayProxyFactoryBean<>(Consumer.class);
+		gatewayProxyFactoryBean.setDefaultRequestChannelName("jdbcConsumerFlow.input");
+		return (AnnotationGatewayProxyFactoryBean) gatewayProxyFactoryBean;
+	}
+
 	@Bean
 	FactoryBean<MessageHandler> aggregator(MessageGroupStore messageGroupStore) {
 		AggregatorFactoryBean aggregatorFactoryBean = new AggregatorFactoryBean();
@@ -232,11 +240,6 @@ public class JdbcConsumerConfiguration {
 		return dataSourceInitializer;
 	}
 
-	@MessagingGateway(name = "jdbcConsumer", defaultRequestChannel = "jdbcConsumerFlow.input")
-	public interface MessageConsumer extends Consumer<Message<?>> {
-
-	}
-
 	private record ParameterFactory(MultiValueMap<String, Expression> columnExpressions,
 			EvaluationContext context) implements SqlParameterSourceFactory {
 

consumer/spring-log-consumer/src/main/java/org/springframework/cloud/fn/consumer/log/LogConsumerConfiguration.java

@@ -21,8 +21,8 @@ import java.util.function.Consumer;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
-import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.gateway.AnnotationGatewayProxyFactoryBean;
 import org.springframework.messaging.Message;
 
 /**
@@ -46,9 +46,12 @@ public class LogConsumerConfiguration {
 			.nullChannel();
 	}
 
-	@MessagingGateway(name = "logConsumer", defaultRequestChannel = "logConsumerFlow.input")
-	private interface MessageConsumer extends Consumer<Message<?>> {
-
+	@Bean
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	AnnotationGatewayProxyFactoryBean<Consumer<Message<?>>> logConsumer() {
+		var gatewayProxyFactoryBean = new AnnotationGatewayProxyFactoryBean<>(Consumer.class);
+		gatewayProxyFactoryBean.setDefaultRequestChannelName("logConsumerFlow.input");
+		return (AnnotationGatewayProxyFactoryBean) gatewayProxyFactoryBean;
 	}
 
 }

consumer/spring-sftp-consumer/src/main/java/org/springframework/cloud/fn/consumer/sftp/SftpConsumerConfiguration.java

@@ -25,9 +25,9 @@ import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.cloud.fn.common.config.ComponentCustomizer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Import;
-import org.springframework.integration.annotation.MessagingGateway;
 import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.file.remote.session.SessionFactory;
+import org.springframework.integration.gateway.AnnotationGatewayProxyFactoryBean;
 import org.springframework.integration.sftp.dsl.Sftp;
 import org.springframework.integration.sftp.dsl.SftpMessageHandlerSpec;
 import org.springframework.integration.sftp.session.SftpRemoteFileTemplate;
@@ -69,9 +69,12 @@ public class SftpConsumerConfiguration {
 		return (flow) -> flow.handle(handlerSpec);
 	}
 
-	@MessagingGateway(name = "sftpConsumer", defaultRequestChannel = "ftpOutboundFlow.input")
-	public interface MessageConsumer extends Consumer<Message<?>> {
-
+	@Bean
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	AnnotationGatewayProxyFactoryBean<Consumer<Message<?>>> sftpConsumer() {
+		var gatewayProxyFactoryBean = new AnnotationGatewayProxyFactoryBean<>(Consumer.class);
+		gatewayProxyFactoryBean.setDefaultRequestChannelName("ftpOutboundFlow.input");
+		return (AnnotationGatewayProxyFactoryBean) gatewayProxyFactoryBean;
 	}
 
 }