I've downloaded Karaf 3.0.8 and tried to enable spring 3.2 and gemini blueprint - without success
karaf@root()> feature:install spring/3.2.17.RELEASE_1
karaf@root()> feature:install gemini-blueprint
Exception in thread "EclipseGeminiBlueprintExtenderThread-25" org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 22 in XML document from URL [bundle://55.0:0/OSGI-INF/blueprint/kar-deployer.xml] is invalid;
nested exception is org.xml.sax.SAXParseException: cvc-complex-type.2.4.c:
The matching wildcard is strict, but no declaration can be found for element 'ext:property-placeholder'.
....
karaf@root()> feature:list -i
Name | Version | Installed | Repository | Description
---------------------------------------------------------------------------------------------------------------------
spring | 3.2.17.RELEASE_1 | x | spring-3.0.8 | Spring 3.2.x support
gemini-blueprint | 1.0.0.RELEASE | x | spring-3.0.8 | Gemini Blueprint Extender
standard | 3.0.8 | x | standard-3.0.8 | Karaf standard feature
config | 3.0.8 | x | standard-3.0.8 | Provide OSGi ConfigAdmin support
region | 3.0.8 | x | standard-3.0.8 | Provide Region Support
package | 3.0.8 | x | standard-3.0.8 | Package commands and mbeans
kar | 3.0.8 | x | standard-3.0.8 | Provide KAR (KARaf archive) support
ssh | 3.0.8 | x | standard-3.0.8 | Provide a SSHd server on Karaf
management | 3.0.8 | x | standard-3.0.8 | Provide a JMX MBeanServer and a set of MBeans in K
karaf@root()> list -t 0
START LEVEL 100 , List Threshold: 0
ID | State | Lvl | Version | Name
------------------------------------------------------------------------------------------------------------
0 | Active | 0 | 4.2.1 | System Bundle
1 | Active | 5 | 2.4.7 | OPS4J Pax Url - aether:
2 | Active | 5 | 2.4.7 | OPS4J Pax Url - wrap:
3 | Active | 8 | 1.8.4 | OPS4J Pax Logging - API
4 | Active | 8 | 1.8.4 | OPS4J Pax Logging - Service
5 | Active | 10 | 3.0.8 | Apache Karaf :: Service :: Guard
6 | Active | 10 | 1.8.4 | Apache Felix Configuration Admin Service
7 | Active | 11 | 3.5.2 | Apache Felix File Install
8 | Active | 12 | 5.0.3 | ASM all classes with debug info
9 | Active | 20 | 1.1.1 | Apache Aries Util
10 | Active | 20 | 1.0.1 | Apache Aries Proxy API
11 | Active | 20 | 1.0.8 | Apache Aries Blueprint CM
12 | Active | 20 | 1.0.4 | Apache Aries Proxy Service
13 | Active | 20 | 1.0.1 | Apache Aries Blueprint API
14 | Resolved | 20 | 1.0.0 | Apache Aries Blueprint Core Compatiblity Fragment Bundle, Hosts: 15
15 | Active | 20 | 1.6.1 | Apache Aries Blueprint Core, Fragments: 14
16 | Active | 24 | 3.0.8 | Apache Karaf :: Deployer :: Spring
17 | Active | 24 | 3.0.8 | Apache Karaf :: Deployer :: Blueprint
18 | Active | 24 | 3.0.8 | Apache Karaf :: Deployer :: Wrap Non OSGi Jar
19 | Active | 25 | 3.0.8 | Apache Karaf :: Region :: Core
20 | Active | 25 | 3.0.8 | Apache Karaf :: Features :: Core
21 | Active | 26 | 3.0.8 | Apache Karaf :: Deployer :: Features
22 | Active | 30 | 2.13.0 | JLine
23 | Active | 30 | 0.2.1 | JLEdit :: Core
24 | Active | 30 | 3.0.8 | Apache Karaf :: Features :: Command
25 | Active | 30 | 3.0.8 | Apache Karaf :: Bundle :: Core
26 | Active | 30 | 3.0.8 | Apache Karaf :: Bundle :: Commands
27 | Active | 30 | 3.0.8 | Apache Karaf :: Shell :: Console
28 | Active | 30 | 3.0.8 | Apache Karaf :: JAAS :: Modules
29 | Active | 30 | 3.0.8 | Apache Karaf :: JAAS :: Config
30 | Active | 30 | 0.14.0 | Apache Mina SSHD :: Core
31 | Active | 30 | 3.0.8 | Apache Karaf :: Shell :: Help System
32 | Active | 30 | 3.0.8 | Apache Karaf :: Shell :: Table
33 | Active | 30 | 3.0.8 | Apache Karaf :: System :: Core
34 | Active | 30 | 3.0.8 | Apache Karaf :: System :: Shell Commands
35 | Active | 30 | 3.0.8 | Apache Karaf :: Shell :: Various Commands
36 | Active | 30 | 1.0.0 | Apache Aries Quiesce API
37 | Active | 30 | 3.0.8 | Apache Karaf :: ConfigAdmin :: Core
38 | Active | 30 | 3.0.8 | Apache Karaf :: ConfigAdmin :: Commands
39 | Active | 30 | 3.0.8 | Apache Karaf :: Instance :: Core
40 | Active | 30 | 3.0.8 | Apache Karaf :: Instance :: Command
41 | Active | 30 | 3.0.8 | Apache Karaf :: JAAS :: Command
42 | Active | 30 | 3.0.8 | Apache Karaf :: Diagnostic :: Core
43 | Active | 30 | 3.0.8 | Apache Karaf :: Diagnostic :: Command
44 | Active | 30 | 3.0.8 | Apache Karaf :: Log :: Core
45 | Active | 30 | 3.0.8 | Apache Karaf :: Log :: Command
46 | Active | 30 | 3.0.8 | Apache Karaf :: Service :: Core
47 | Active | 30 | 3.0.8 | Apache Karaf :: Service :: Command
48 | Active | 30 | 1.0.0.v20110524 | Region Digraph
49 | Active | 30 | 3.0.8 | Apache Karaf :: Region :: Persistence
50 | Active | 30 | 3.0.8 | Apache Karaf :: Region :: Shell Commands
51 | Active | 30 | 3.0.8 | Apache Karaf :: Package :: Core
52 | Active | 30 | 3.0.8 | Apache Karaf :: Package :: Commands
53 | Active | 30 | 3.0.8 | Apache Karaf :: KAR :: Core
54 | Active | 30 | 3.0.8 | Apache Karaf :: KAR :: Command
55 | Active | 30 | 3.0.8 | Apache Karaf :: Deployer :: Karaf Archive (.kar)
56 | Active | 30 | 2.0.7 | Apache MINA Core
57 | Active | 30 | 3.0.8 | Apache Karaf :: Shell :: SSH
58 | Active | 30 | 3.0.8 | Apache Karaf :: Management
59 | Active | 30 | 1.1.1 | Apache Aries JMX API
60 | Active | 30 | 1.1.6 | Apache Aries JMX Core
61 | Active | 30 | 1.1.0 | Apache Aries JMX Blueprint API
62 | Active | 30 | 1.1.0 | Apache Aries JMX Blueprint Core
63 | Active | 30 | 1.0.0 | Apache Aries JMX Whiteboard
64 | Active | 30 | 1.0.0.6 | Apache ServiceMix :: Bundles :: aopalliance
65 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-core
66 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-expression
67 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-beans
68 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-aop
69 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-context
70 | Active | 30 | 3.2.17.RELEASE_1 | Apache ServiceMix :: Bundles :: spring-context-support
71 | Active | 30 | 1.0.0.RELEASE | gemini-blueprint-io
72 | Active | 30 | 1.0.0.RELEASE | gemini-blueprint-core
73 | Active | 30 | 1.0.0.RELEASE | gemini-blueprint-extender
After restart I've got following exception printed for almost every bundle
73 - org.eclipse.gemini.blueprint.extender - 1.0.0.RELEASE | Application context refresh failed (OsgiBundleXmlApplicationContext(bundle=org.apache.karaf.config.command, config=OSGI-INF/blueprint/shell-config.xml))
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 25 in XML document from URL [bundle://38.0:0/OSGI-INF/blueprint/shell-config.xml] is invalid; nested exception is org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'command-bundle'.
For some bundles there's a problem with command-bundle element and for others with ext:property-placeholder
So it looks like Karaf core bundles have invalid blueprint xml? Is it a bug?
The Apache Karaf 2.x and 3.x versions use blueprint internally. Blueprint specification is somewhat limited and does not cover any extension mechanism through namespaces. This is supported by both Aries Blueprint and Gemini Blueprint, but in different ways. Those Karaf versions rely on Aries Blueprint, so it's a bit hard to get Gemini Blueprint working.
Karaf 4.x does not use Blueprint internally anymore, so it should be much easier to install Gemini Blueprint there.
That said, Gemini Blueprint isn't much active, so you should have a look at the Aries Blueprint implementation instead. Fwiw, Aries Blueprint also provides a full Spring compatibility layer if you need.