Default manifest

Each time Wuff processes an OSGi-bundle[1], it generates an OSGi manifest. It uses various project properties - version, name, dependencies, classpath etc. - as input for manifest generation. The generated manifest does not pollute program sources: it is generated as a temporary file in buildDir. Wuff instructs gradle Jar task to include the generated OSGi manifest into the resulting JAR-file.

When the programmer gives no additional instructions on OSGi-manifest generation, the generated OSGi manifest is called default manifest.

Lets inspect how default manifest looks like.

1. Create folder "tutorials/MyOsgiManifest", create file "build.gradle" in it, insert code:

buildscript {
  repositories {
    mavenLocal()
    jcenter()
  }

  dependencies {
    classpath 'org.akhikhl.wuff:wuff-plugin:0.0.1'
  }
}

apply plugin: 'java'
apply plugin: 'osgi-bundle'

repositories {
  mavenLocal()
  jcenter()
}

2. Invoke on command line:

gradle build

3. Open file "tutorials/MyOsgiPlugin/build/libs/MyOsgiPlugin-1.0.0.0.jar", open "META-INF/MANIFEST.MF", it should contain something like this:

Manifest-Version: 1.0
Bundle-SymbolicName: MyOsgiPlugin
Bundle-Version: 1.0.0.0
Bundle-Name: MyOsgiPlugin
Require-Bundle: org.eclipse.osgi
Bundle-ManifestVersion: 2
Bnd-LastModified: 1398375756000
Created-By: 1.8.0_05 (Oracle Corporation)
Tool: Bnd-2.1.0.20130426-122213
Bundle-Classpath: .

This is how default manifest is generated:

• Bundle-SymbolicName and Bundle-Name are assigned to project name.
• Bundle-Version is assigned to project version. If project version is not specified in "build.gradle", the default value "1.0.0.0" is used for Bundle-Version.
• Require-Bundle is assigned to "org.eclipse.osgi" because of apply plugin: 'osgi-bundle' in "build.gradle".
• Bundle-Classpath is assigned to "root folder" in the context of JAR-file.
• All other fields are specific to BND-tool, which is invoked via chain Wuff -> gradle 'osgi' plugin -> BND-tool.

[1]: In Wuff context OSGi-bundle is a gradle project with one of the plugins applied: "eclipse-bundle", "eclipse-equinox-app", "eclipse-ide-app", "eclipse-ide-bundle", "eclipse-rcp-app", "osgi-bundle".

Next page: Manifest attributes in build.gradle.