Add Spring Cloud Stream function based apps

Resolves #135

spring-cloud-stream-function-bindings/log-sink/src/main/java/com/example/logsink/LogConsumerConfiguration.java

@@ -0,0 +1,31 @@
+package com.example.logsink;
+
+import java.util.function.Consumer;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.dsl.IntegrationFlows;
+import org.springframework.integration.handler.LoggingHandler;
+import org.springframework.messaging.Message;
+
+@Configuration
+public class LogConsumerConfiguration {
+	public LogConsumerConfiguration() {
+	}
+
+	@Bean
+	IntegrationFlow logConsumerFlow() {
+		return IntegrationFlows.from(MessageConsumer.class, (gateway) -> gateway.beanName("logConsumer"))
+				.handle((payload, headers) -> {
+					if (payload instanceof byte[]) {
+						return new String((byte[]) payload);
+					}
+					return payload;
+				})
+				.log(LoggingHandler.Level.INFO, "log-consumer", "payload")
+				.get();
+	}
+
+	private interface MessageConsumer extends Consumer<Message<?>> {}
+}

spring-cloud-stream-function-bindings/log-sink/src/main/java/com/example/logsink/LogSinkApplication.java

@@ -0,0 +1,12 @@
+package com.example.logsink;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class LogSinkApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(LogSinkApplication.class, args);
+	}
+}