055e9a40db
JIRA: https://jira.spring.io/browse/INT-4457 When an `IntegrationFlow` is reply-based (we expect a reply in the beginning) and `log()` (or `wireTap()`) is used in the end, we are forced to add an empty `bridge()` in the end to ensure a `replyChannel` header routing * Fix `IntegrationFlowDefinition` to add `enrichHeaders()` in the end to populate a `nullChannel` as a `replyChannel` header if that is missed in the request message headers. This way we cover both use-cases when we expect reply from the flow and when it is used as a one-way scenario * Improve a `HeaderEnricher` do not create a new `Message` if there are no new headers to add/remove * Remove a note from the `dsl.adoc` about now redundant `bridge()` after `log()` * Resolve TODO in the `.handle()` paragraph * Restore anonymous class in the MessageHistoryIntegrationTests: Mockito can't mock/spy lambdas because they are `final` classes * Introduce `IntegrationFlowDefinition.logAndReply()` operator * Fix logging message Doc Polishing
Spring Integration 
Checking out and Building
To check out the project and build from source, do the following:
git clone git://github.com/spring-projects/spring-integration.git
cd spring-integration
./gradlew build
NOTE: While Spring Integration runs with Java SE 6 or higher, a Java 8 compiler is required to build the project.
If you encounter out of memory errors during the build, increase available heap and permgen for Gradle:
GRADLE_OPTS='-XX:MaxPermSize=1024m -Xmx1024m'
To build and install jars into your local Maven cache:
./gradlew install
To build api Javadoc (results will be in build/api):
./gradlew api
To build reference documentation (results will be in build/reference):
./gradlew reference
To build complete distribution including -dist, -docs, and -schema zip files (results will be in build/distributions)
./gradlew dist
Using Eclipse
To generate Eclipse metadata (.classpath and .project files), do the following:
./gradlew eclipse
Once complete, you may then import the projects into Eclipse as usual:
File -> Import -> Existing projects into workspace
Browse to the 'spring-integration' root directory. All projects should import free of errors.
Using IntelliJ IDEA
To generate IDEA metadata (.iml and .ipr files), do the following:
./gradlew idea
Resources
For more information, please visit the Spring Integration website at: http://projects.spring.io/spring-integration