[KARAF-4693] shell:new issue with class wildcards

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.6
• Fix Version/s: 4.1.0, 4.0.7
• Component/s: karaf
• Flags: Patch
• Assignee: Freeman Yue Fang
• Reporter: Paolo Antinori
• Created: 02/Sep/16 09:28
• Updated: 15/Sep/18 16:35
• Resolved: 05/Sep/16 03:23

Description

Karaf shell fails if you run this command:

a=shell:new java.util.ArrayList 2

2016-09-02 11:15:51,525 | ERROR | nsole user karaf | ShellUtil                        | 43 - org.apache.karaf.shell.core - 4.0.6 | Exception caught while executing command
java.lang.IllegalStateException
	at org.apache.karaf.shell.support.converter.GenericType.parametersOf(GenericType.java:161)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.support.converter.GenericType.[init](GenericType.java:53)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.support.converter.GenericType.parametersOf(GenericType.java:154)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.support.converter.GenericType.[init](GenericType.java:53)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.commands.impl.NewAction.findMatchingConstructors(NewAction.java:167)[41:org.apache.karaf.shell.commands:4.0.6]
	at org.apache.karaf.shell.commands.impl.NewAction.execute(NewAction.java:89)[41:org.apache.karaf.shell.commands:4.0.6]
	at org.apache.karaf.shell.impl.action.command.ActionCommand.execute(ActionCommand.java:83)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:67)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.impl.console.osgi.secured.SecuredCommand.execute(SecuredCommand.java:87)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.Closure.executeCmd(Closure.java:480)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.Closure.executeStatement(Closure.java:406)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.Pipe.run(Pipe.java:108)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:182)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.Closure.execute(Closure.java:119)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.felix.gogo.runtime.CommandSessionImpl.execute(CommandSessionImpl.java:94)[43:org.apache.karaf.shell.core:4.0.6]
	at org.apache.karaf.shell.impl.console.ConsoleSessionImpl.run(ConsoleSessionImpl.java:274)[43:org.apache.karaf.shell.core:4.0.6]
	at java.lang.Thread.run(Thread.java:745)[:1.8.0_102]

The reason for that is not really that it can't handle generics but it the logic that probe for the best matching constructor, that at some point, in this class:

https://github.com/apache/karaf/blob/68bef0ced72a3fe192cfe496b3fff654b49b2377/shell/core/src/main/java/org/apache/karaf/shell/support/converter/GenericType.java#L161-L161

sees type set to "? extends E" that is not able to handle, thus throwing the blocking exception.

It's enough to replace that exception with an empty return, to bypass the failing iteration and have the command to succeed.

Issue Links

• links to: GitHub Pull Request #236