[SLING-3370] Bootdelegation support for third party library

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Launchpad Base 2.5.0
• Fix Version/s: Launchpad Base 2.5.2
• Component/s: Launchpad
• Assignee: Amit Gupta
• Reporter: Rohit Kumar
• Created: 04/Feb/14 17:10
• Updated: 26/Jul/14 17:35
• Resolved: 26/Feb/14 09:27

Description

Requirement:
1) Bootdelegate third party library in SLing OSGI framework.
2) Bootdelegated classes and resources should be looked up from configured third party jars only. Similar classes from parent classloaders should not leak into system. This case arises usually in Web deployment scenario.

Infact we want to bootdelegate RSA library and at the same time prevent interference from parent classloaders in Web deployment model.

Approach:

1) We extend SlingLauncherClassloader to scan a predefined path (say <launchpadhome>/lib/etx) for jar files and add them to its classpath. This is done at startup. SlingLauncherClassloader will try to load class from its classpath before trying parent classloaders. Currently it is done for org.apache.sling.launchpad.base.jar.
2) The packages can be configured for bootdelegation using sling properties:
sling.bootdelegation.class.<any bootdelegated class>=<bootdelegated package>