RepoIndex program is a small Java program that generates repository indexes compliant with the Repository Service Specification version 1.0, as defined in the OSGi Service Platform Service Compendium, Release 5. It can recurse over a directory structure generates a repository.xml file. The URLs can be rewritten using a template.
RepoIndex is a command line application that can easily be integrated in scripts. It is also an OSGi bundle that publishes a service under the ResourceIndexer interface, and a standalone library that can be used in conventional Java runtimes. While primarily intended for indexing OSGi bundles, it can generate metadata for any arbitrary file type by extending it with pluggable ResourceAnalyzer objects.
RepoIndex is shipped as two alternative forms:
-
org.osgi.impl.bundle.repoindex.libis a pure library and OSGi bundle. Use this if you want to embed index generation functionality into an existing application. See sections "Library Usage" and "OSGi Bundle Usage" below. -
org.osgi.impl.bundle.repoindex.cliis a standalone command-line application. See section "Command Line Usage" below. -
org.osgi.impl.bundle.repoindex.antis a convenience library for ANT. See section "Ant Task Usage" below.
N.B.: The cli and ant libraries do not depend on lib.
The basic command line usage is as follows:
java -jar org.osgi.impl.bundle.repoindex.cli.jar bundles/*.jar
This generates an index file in the local directory named index.xml.gz with metadata for all JAR files found under the bundles directory. The content URLs for the resources will be relative to the current directory, i.e.:
<attribute name='osgi.content' value='bundles/foo.jar'/>
The full set of command line options can be obtained by executing with the -h option.
If custom resource analyzers are required (see below), these can be simply placed on the Java runtime classpath. In this case the java -jar launch method cannot be used, so it is necessary to launch with the application class name as follows:
java -cp org.osgi.impl.bundle.repoindex.cli.jar;MyAnalyzer.jar \
org.osgi.impl.bundle.bindex.cli.Index \
bundles/*.jar
RepoIndex can be used as an Ant Task by adding a taskdef using the org.osgi.impl.bundle.repoindex.ant.jar library:
<taskdef name="repoindex" classname="org.osgi.impl.bundle.repoindex.ant.RepoIndexTask" >
<classpath>
<path location="../cnf/path/to/org.osgi.impl.bundle.repoindex.ant.jar" />
</classpath>
</taskdef>
If custom resource analyzers are required (see below), these can be simply added to the classpath.
The available options are configured through the tasks attributes and the resources are specified using one or more filesets.
<target name="generate-index">
<repoindex name="My Repository" verbose="false" pretty="true"
compressed="false" out="${repository.dir}/index.xml">
<fileset dir="${repository.dir}" includes="**/*.jar" />
</repoindex>
</target>
RepoIndex can be used as a JAR library in a conventional Java application or web/JavaEE container by adding org.osgi.impl.bundle.repoindex.lib.jar to your application classpath. The API is as follows:
RepoIndex indexer = new RepoIndex();
// optional: add one or more custom resource analyzers
indexer.add(new MyExtenderResourceAnalyzer(), null);
// optional: set config params
Map<String, String> config = new HashMap<String, String>();
config.put(ResourceIndexer.REPOSITORY_NAME, "My Repository");
Set<File> inputs = findInputs();
OutputStream output = new FileOutputStream("index.xml.gz");
indexer.index(inputs, output, config);
Note that it is not generally encouraged for client code to directly instantiate RepoIndex as shown, since this creates an implementation dependency. It is better to use the ResourceIndexer API interface along with a Dependency Injection framework such as Guice or Spring to supply the instance. Even better, use ResourceIndexer as an OSGi Service as shown in the next section.
Resource analyzers are added with an optional Filter, which is matched against incoming resources as they are processed. If the filter is null then the analyzer is invoked for all incoming resources. Filters are generated using the org.osgi.framework.FrameworkUtil.createFilter() method, for example:
import static org.osgi.framework.FrameworkUtil.createFilter;
// ...
Filter warFilter = createFilter("(name=*.war)");
indexer.add(new WarAnalyzer(), warFilter);
For more information on the filter string syntax and the properties available to match, see "Resource Analyzers" below.
org.osgi.impl.bundle.repoindex.lib is also an OSGi bundle that publishes a service under the interface org.osgi.service.indexer.ResourceIndexer when in ACTIVE state. For example, to use the ResourceIndexer service from a Declarative Services component:
@Reference
public void setIndexer(ResourceIndexer indexer) {
this.indexer = indexer;
}
public void doSomething() {
// ...
indexer.index(input, output, config);
}
When used as an OSGi bundle, RepoIndex uses the "Whiteboard Pattern" to find custom resource analyzers. The filter, if required, can be given as a property of the service. For example to register an analyzer for WAR files, again using Declarative Services annotations:
@Component(property = "filter=(name=*.war)")
public class WarAnalyzer implements ResourceAnalyzer {
// ...
}
RepoIndex is expected to be used primarily for analyzing and indexing OSGi bundles. However it is designed to be extensible to analyze any other kind of resource, since the OSGi Repository specification supports arbitrary resource types. It can also be extended to extract additional metadata from existing known types such as OSGi bundles.
For example, we may wish to extend RepoIndex to understand configuration files, script files, or native libraries. Alternatively we may wish to process custom extender headers from the MANIFEST.MF of OSGi bundles.
The ResourceAnalyzer interfaces defines a single method analyzeResource:
public interface ResourceAnalyzer {
static final String FILTER = "filter";
void analyzeResource(Resource resource,
List<Capability> capabilities,
List<Requirement> requirements) throws Exception;
}
The analyzeResource method takes a Resource object and the lists of already discovered Requirements and Capabilities. An analyzer is permitted to add zero to many of each but it must not remove or alter any existing entries. A Builder class is provided as a convenience for constructing instances of Capability and Requirement.
The Resource interface is an abstraction over the types of resource that may be supplied to the analyzer. Analyzer implementations are not expected to implement Resource. The abridged interface definition is as follows:
public interface Resource {
String getLocation();
Dictionary<String, Object> getProperties();
long getSize();
InputStream getStream() throws IOException;
Manifest getManifest() throws IOException;
List<String> listChildren(String prefix) throws IOException;
Resource getChild(String path) throws IOException;
void close();
}
We expect that in the majority of cases the resource will be an OSGi bundle, and therefore a JAR file. Therefore we provide the getManifest, listChildren and getChild methods as optimisations, so that every analyzer does not need to re-parse the JAR contents. If the resource does not contain a META-INF/MANIFEST.MF then getManifest will return null. If the resource is not a "compound" resource such as a JAR or ZIP then listChildren and getChild will return null for all input values.
Access to the underlying content of the file is always available through the getStream method but this should be treated as an expensive operation that should only be called when the data required is not otherwise available from the properties, manifest or children.
The following example shows an analyzer for a custom extender header, Help-Docs. If the analyzer finds this header in the bundle manifest, it generates both a capability and a requirement:
public class HelpExtenderAnalyzer {
public void analyzeResource(Resource resource,
List<Capability> caps,
List<Requirement> reqs) {
// Ignore this resource if no META-INF/MANIFEST.MF
// or Help-Docs header
Manifest manifest = resource.getManifest();
if (manifest == null)
return;
String help = manifest.getMainAttributes().getValue("Help-Docs");
if (help == null)
return;
// Generate a new requirement
Requirement req = new Builder()
.setNamespace("help.system")
.addDirective("filter", "(&(version>=1.0)(!(version>=2.0)))")
.buildRequirement();
reqs.add(req);
// Generate a new capability
String bsn = manifest.getMainAttributes()
.getValue(Constants.BUNDLE_SYMBOLICNAME);
Capability cap = new Builder()
.setNamespace("help.doc")
.addAttribute("version", new Version("1.0"))
.addAttribute("bsn", bsn);
caps.add(cap);
}
}
The getProperties method on Resource returns a dictionary of properties for the resource. These properties can be used to define filters so that an analyzer can be invoked only for a subset of interesting resources. The property names are defined as static constants on the Resource interface:
name: the simple name of the resource, i.e. usually the filename excluding its location path;location: the full location of the resource (also available from thegetLocationmethod);size: the size (as aLongvalue) of the resource in bytes (also available from thegetSizemethod);lastmodified: the last-modified timestamp of the resource, as aLongvalue representing milliseconds since the epoch (00:00:00 GMT, January 1, 1970).
The filter expression syntax is described in section 3.2.7 of the OSGi Core Specification.
For example, to select files named either foo.jar or ending with the .ear extension, created on or after midnight on 1 January 2010:
(&(|(name=foo.jar)(name=*.ear))(lastmodified>=1262217600753))
Resource analyzers should be packaged for delivery as OSGi bundles that register services under the ResourceAnalyzer interface. The RepoIndex command-line application uses a lightweight OSGi-like runtime called PojoSR to configure services, and looks for resource analyzers using the whiteboard pattern.
Note that if an analyzer implementation relies on Declarative Service to manage and register it as a service, then it will be necessary to place a Declarative Service implementation (also known as a Service Component Runtime or SCR) on the RepoIndex classpath. For example the Apache Felix SCR can be used as follows:
java -cp org.osgi.impl.bundle.repoindex.cli.jar;org.apache.felix.scr-1.6.0.jar;MyAnalyzer.jar \
org.osgi.impl.bundle.bindex.cli.Index \
bundles/*.jar