A.4. Wrap URL Handler
Overview
If you need to reference a JAR file that is not already packaged as a bundle, you can use the Wrap URL handler to convert it dynamically. The implementation of the Wrap URL handler is based on Peter Krien's open source Bnd utility.
Syntax
A Wrap URL has the following syntax:
wrap:locationURL[,instructionsURL][$instructions]
The locationURL can be any URL that locates a JAR (where the referenced JAR is not formatted as a bundle). The optional instructionsURL references a Bnd properties file that specifies how the bundle conversion is performed. The optional instructions is an ampersand,
&, delimited list of Bnd properties that specify how the bundle conversion is performed.
Default instructions
In most cases, the default Bnd instructions are adequate for wrapping an API JAR file. By default, Wrap adds manifest headers to the JAR's
META-INF/Manifest.mf file as shown in Table A.1, “Default Instructions for Wrapping a JAR”.
| Manifest Header | Default Value |
|---|---|
Import-Package | *;resolution:=optional |
Export-Package | All packages from the wrapped JAR. |
Bundle-SymbolicName | The name of the JAR file, where any characters not in the set [a-zA-Z0-9_-] are replaced by underscore, _. |
Examples
The following Wrap URL locates version 1.1 of the
commons-logging JAR in a Maven repository and converts it to an OSGi bundle using the default Bnd properties:
wrap:mvn:commons-logging/commons-logging/1.1
The following Wrap URL uses the Bnd properties from the file,
E:\Data\Examples\commons-logging-1.1.bnd:
wrap:mvn:commons-logging/commons-logging/1.1,file:E:/Data/Examples/commons-logging-1.1.bnd
The following Wrap URL specifies the
Bundle-SymbolicName property and the Bundle-Version property explicitly:
wrap:mvn:commons-logging/commons-logging/1.1$Bundle-SymbolicName=apache-comm-log&Bundle-Version=1.1
If the preceding URL is used as a command-line argument, it might be necessary to escape the dollar sign,
\$, to prevent it from being processed by the command line, as follows:
wrap:mvn:commons-logging/commons-logging/1.1\$Bundle-SymbolicName=apache-comm-log&Bundle-Version=1.1
Reference
For more details about the
wrap URL handler, see the following references:
- The Bnd tool documentation, for more details about Bnd properties and Bnd instruction files.
- The original Pax URL Wrap Protocol documentation.
