Previously, there was a `synchronized` block in the `GroovyScriptExecutingMessageProcessor`
to achieve thread-safety around script variables.
In addition, the parsing and executing logic was delegated to `GroovyScriptFactory`, who, in turn,
has its own `synchronized` around script parsing.
This causes a bottleneck in a messaging architecture.
* Introduce `GroovyScriptExecutor implements ScriptExecutor`
to encapsulate Groovy parsing and executing logic
* synchronize via `ReentrantLock` only when script resource `isModified()`
JIRA: https://jira.springsource.org/browse/INT-3166
INT-3166: Fixes and Polishing
INT-3166: add synchronized double check
INT-3166: Remove `GroovyScriptExecutor`
Polishing tests and logic around exceptions
Fix up some white space issues in Groovy*Tests
Previously, there was no logic to check, if a JSR223 script
was modified should be refreshed from the external resource.
* Fix `RefreshableResourceScriptSource` to take care of refreshing
on call `isModified()`
* Add `scriptSource.isModified()` before getting script text
* Introduce `ScriptSourceFactoryBean` to avoid I/O operations, when
there is need to refresh script resource - `refreshDelay < 0`
JIRA: https://jira.springsource.org/browse/INT-3164
INT-3164: change the refresh mutation logic
Remove factory bean - no longer needed.
* Add `<script>` and `<expression>` to `<int:inbound-channel-adapter>`
* Refactoring for `DefaultInboundChannelAdapterParser`
* Introduce `ScriptExecutingMessageSource` to allow scripts' `MessageProcessor`
implementations work as a source for polling endpoint
JIRA: https://jira.springsource.org/browse/INT-2867
INT-2867: documentation
In addition the tests for Lifecycle attributes
Polishing
Make 'lang' attribute optional on a script element and
attempt to derive the language from the file extension.
Change return value on ScriptParser.deriveLanguageFromExtension to the language name
Polishing (PR Comments)
* add XSD element for nested router type
* add tests on the matter
* polishing for RouterParserTests
JIRA: https://jira.springsource.org/browse/INT-2893
INT-2893: Polishing
INT-2893: after rebasing to 3.0
XSD changes reverted from 2.2 and moved to 3.0
INT-2893 Polishing
Factor out common elements; fixing missing documentation for
`expression` within a `router` within a `chain`.
