One tough point is that it isn’t attainable to have a qualifier with out specifying the entire numeric parts of the model. so that you can’t specify 1. 2. build-59; you need to specify 1. 2. zero. build-59. OSGi makes use of this universal version-number structure for versioning either bundles and Java programs. In bankruptcy nine, we’ll talk about high-level techniques for coping with model numbers in your programs, bundles, and purposes. obtain from Wow! book Defining bundles with metadata 2. five. three 39 Code visibility Human-readable and bundle-identification metadata are worthy, yet they don’t cross some distance in permitting you to explain your bundle’s modularity features. The OSGi specification defines metadata for comprehensively describing which code is noticeable internally in a package deal and which inner code is noticeable externally. OSGi metadata for code visibility captures the next info: ■ ■ ■ inner package deal type path—The code forming the package Exported inner code—Explicitly uncovered code from the package category direction for sharing with different bundles Imported exterior code—External code on which the package deal classification course code relies each one of those components captures separate yet comparable information regarding which Java sessions are available on your package and by way of your package. We’ll disguise every one intimately; yet sooner than we do this, let’s step again and dissect the way you use JAR records and the Java classification direction in conventional Java programming. this can offer you a foundation for comparability to OSGi’s method of code visibility. very important! regular JAR documents commonly fail as bundles due to the fact they have been written below the idea of world kind visibility (i. e. , if it’s at the type direction, you should use it). If you’re going to create powerful bundles, you might want to unfastened your self from this outdated assumption and completely comprehend and settle for that sort visibility for bundles relies in basic terms at the primitives we describe during this part. To make this aspect very transparent, we’ll pass into problematic information about sort visibility ideas for traditional JAR records as opposed to package JAR records. even supposing this can seem to be a lesson within the arcane, it’s serious to appreciate those changes. CODE VISIBILITY IN commonplace JAR records AND the category direction typically conversing, you collect Java resource records into periods after which use the jar software to create a JAR dossier from the generated sessions. If the JAR dossier has a Main-Class characteristic within the take place dossier, you could run the applying like this: java -jar app. jar If now not, you upload it to the category direction and begin the appliance anything like this: java -cp app. jar org. foo. major determine 2. nine indicates the levels the JVM is going via. First it searches for the category laid out in the Main-Class characteristic or the only distinct at the command line. If it unearths the category, it searches it for a static public void main(String[]) process. If one of these process is located, it invokes it to begin the appliance. because the software executes, any extra periods wanted by way of the applying are came upon through looking the category course, which consists of the appliance sessions within the JAR dossier and the traditional JRE sessions (and something you might have further to the category path).