07a6fb3a9a
`IMAPFolder.idle()` by default keeps idle-ing after each response. We don't need that, because we want to fetch the new mails immediately (over the same connection). To make `idle()` not keep on going, we called `folder.isOpen()` which in most cases makes `idle()` stop by calling `noop()` internally (to keep the connection alive) which leads to the current `idle()`-call being canceled. The problem this commits addresses is that the call to `noop()` only happens if there were no calls in the last second. There is a check for that in `com.sun.mail.imap.IMAPFolder.keepConnectionAlive`. So if a new message appears less then a second after idle started, we will miss it. This new way interrupts `idle()` more often than before, e.g. when there is an expunge-message (i.e. a message was deleted), which we don't care about. But the subsequent `receive()` in IdleTask will simply get no messages and then turn around and start idle-ing again. **Cherry-pick to `5.3.x` & `master`**
Spring Integration 
Code of Conduct
Please see our Code of conduct.
Reporting Security Vulnerabilities
Please see our Security policy.
Checking out and Building
To check out the project and build from the source, do the following:
git clone git://github.com/spring-projects/spring-integration.git
cd spring-integration
./gradlew clean test
or
./gradlew clean testAll
The latter runs additional tests (those annotated with @LongRunningIntegrationTest); it is a more thorough test but takes quite a lot longer to run.
The test results are captured in build/reports/tests/test (or .../testAll) under each module (in HTML format).
Add --continue to the command to perform a complete build, even if there are failing tests in some modules; otherwise the build will stop after the current module(s) being built are completed.
NOTE: While Spring Integration runs with Java SE 8 or higher, a Java 11 compiler is required to build the project.
To build and install jars into your local Maven cache:
./gradlew publishToMavenLocal
To build api Javadoc (results will be in build/api):
./gradlew api
To build the reference documentation (results will be in build/docs/asciidoc and build/docs/asciidocPdf):
./gradlew reference
To build complete distribution including -dist, -docs, and -schema zip files (results will be in build/distributions):
./gradlew dist
Using Eclipse or Spring Tool Suite (with BuildShip Plugin)
If you have the BuildShip plugin installed,
File -> Import -> Gradle -> Existing Gradle Project
Using Eclipse or Spring Tool Suite (when the BuildShip Plugin is not installed)
To generate Eclipse metadata (.classpath and .project files, etc), do the following:
./gradlew eclipse
Once complete, you may then import the projects into Eclipse as usual:
File -> Import -> General -> Existing projects into workspace
Browse to the 'spring-integration' root directory. All projects should import free of errors.
Using IntelliJ IDEA
To import the project into IntelliJ IDEA:
File -> Open... -> and select build.gradle from spring-integration project root directory
Guidelines
See also Contributor Guidelines.
Resources
For more information, please visit the Spring Integration website at: https://spring.io/projects/spring-integration