Streamline Integration Starter and add Java DSL to it

This commit streamlines the Integration Starter by removing the file
http, ip, and stream modules as they are not always used by a majority
of apps that use Spring Integration and can also pull in other, unwanted
dependencies.

Additionally, a dependency on spring-integration-java-dsl has been
added. This makes it easy for users to configure Spring Integration
using Java configuration (the recommended approach), rather than via
XML. The Integration sample has been updated to use the DSL. Further
improvements could be made once the sample is using Java 8.

Closes gh-5528

Author: wilkinsona

spring-boot-dependencies/pom.xml

@@ -147,6 +147,7 @@
 		<spring-data-releasetrain.version>Hopper-SR1</spring-data-releasetrain.version>
 		<spring-hateoas.version>0.19.0.RELEASE</spring-hateoas.version>
 		<spring-integration.version>4.3.0.M1</spring-integration.version>
+		<spring-integration-java-dsl.version>1.1.2.RELEASE</spring-integration-java-dsl.version>
 		<spring-loaded.version>1.2.5.RELEASE</spring-loaded.version>
 		<spring-mobile.version>1.1.5.RELEASE</spring-mobile.version>
 		<spring-plugin.version>1.2.0.RELEASE</spring-plugin.version>
@@ -2064,6 +2065,11 @@
 					</exclusion>
 				</exclusions>
 			</dependency>
+			<dependency>
+				<groupId>org.springframework.integration</groupId>
+				<artifactId>spring-integration-java-dsl</artifactId>
+				<version>${spring-integration-java-dsl.version}</version>
+			</dependency>
 			<dependency>
 				<groupId>org.springframework.mobile</groupId>
 				<artifactId>spring-mobile-device</artifactId>

spring-boot-samples/spring-boot-sample-integration/pom.xml

@@ -27,6 +27,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-actuator</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.integration</groupId>
+			<artifactId>spring-integration-file</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.integration</groupId>
 			<artifactId>spring-integration-jmx</artifactId>

spring-boot-samples/spring-boot-sample-integration/src/main/java/sample/integration/HelloWorldService.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +16,16 @@
 
 package sample.integration;
 
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Service;
 
-@Component
+@Service
 public class HelloWorldService {
 
-	@Autowired
-	private ServiceProperties configuration;
+	private final ServiceProperties configuration;
+
+	public HelloWorldService(ServiceProperties configuration) {
+		this.configuration = configuration;
+	}
 
 	public String getHelloMessage(String name) {
 		return this.configuration.getGreeting() + " " + name;

spring-boot-samples/spring-boot-sample-integration/src/main/java/sample/integration/SampleEndpoint.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,16 +19,18 @@
 import java.io.File;
 import java.io.FileInputStream;
 
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.integration.annotation.MessageEndpoint;
 import org.springframework.integration.annotation.ServiceActivator;
 import org.springframework.util.StreamUtils;
 
 @MessageEndpoint
 public class SampleEndpoint {
 
-	@Autowired
-	private HelloWorldService helloWorldService;
+	private final HelloWorldService helloWorldService;
+
+	public SampleEndpoint(HelloWorldService helloWorldService) {
+		this.helloWorldService = helloWorldService;
+	}
 
 	@ServiceActivator
 	public String hello(File input) throws Exception {

spring-boot-samples/spring-boot-sample-integration/src/main/java/sample/integration/SampleIntegrationApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,18 +16,69 @@
 
 package sample.integration;
 
+import java.io.File;
+
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.annotation.ImportResource;
+import org.springframework.context.annotation.Bean;
+import org.springframework.integration.channel.DirectChannel;
+import org.springframework.integration.dsl.IntegrationFlow;
+import org.springframework.integration.dsl.IntegrationFlows;
+import org.springframework.integration.dsl.SourcePollingChannelAdapterSpec;
+import org.springframework.integration.dsl.core.Pollers;
+import org.springframework.integration.dsl.support.Consumer;
+import org.springframework.integration.file.FileReadingMessageSource;
+import org.springframework.integration.file.FileWritingMessageHandler;
 
 @SpringBootApplication
 @EnableConfigurationProperties(ServiceProperties.class)
-@ImportResource("integration-context.xml")
 public class SampleIntegrationApplication {
 
+	@Bean
+	public FileReadingMessageSource fileReader() {
+		FileReadingMessageSource reader = new FileReadingMessageSource();
+		reader.setDirectory(new File("target/input"));
+		return reader;
+	}
+
+	@Bean
+	public DirectChannel inputChannel() {
+		return new DirectChannel();
+	}
+
+	@Bean
+	public DirectChannel outputChannel() {
+		return new DirectChannel();
+	}
+
+	@Bean
+	public FileWritingMessageHandler fileWriter() {
+		FileWritingMessageHandler writer = new FileWritingMessageHandler(
+				new File("target/output"));
+		writer.setExpectReply(false);
+		return writer;
+	}
+
+	@Bean
+	public IntegrationFlow integrationFlow(SampleEndpoint endpoint) {
+		return IntegrationFlows.from(fileReader(), new FixedRatePoller())
+				.channel(inputChannel()).handle(endpoint).channel(outputChannel())
+				.handle(fileWriter()).get();
+	}
+
 	public static void main(String[] args) throws Exception {
 		SpringApplication.run(SampleIntegrationApplication.class, args);
 	}
 
+	private static class FixedRatePoller
+			implements Consumer<SourcePollingChannelAdapterSpec> {
+
+		@Override
+		public void accept(SourcePollingChannelAdapterSpec spec) {
+			spec.poller(Pollers.fixedRate(500));
+		}
+
+	}
+
 }

spring-boot-samples/spring-boot-sample-integration/src/main/resources/application.properties

@@ -1,4 +1,2 @@
-logging.file: /tmp/logs/app.log
 logging.level.org.springframework.integration.file: DEBUG
 service.greeting: Hello
-debug: true

spring-boot-samples/spring-boot-sample-integration/src/main/resources/integration-context.xml

@@ -32,19 +32,7 @@
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.integration</groupId>
-			<artifactId>spring-integration-file</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.integration</groupId>
-			<artifactId>spring-integration-http</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.integration</groupId>
-			<artifactId>spring-integration-ip</artifactId>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.integration</groupId>
-			<artifactId>spring-integration-stream</artifactId>
+			<artifactId>spring-integration-java-dsl</artifactId>
 		</dependency>
 	</dependencies>
 </project>