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6.4. Native System Information Access
All plug-ins have access to a set of native libraries that allow plug-in components to ask the underlying operating system for details about the machine on which the plug-in is running. Some of these features are not available on all hardware and OS platforms - only those platforms that have the native libraries available will be able to support all features described below. However, for those platforms that do not have the native libraries available, there will still be a limited feature set available.
6.4.1. SystemInfoFactory and SystemInfo
The plug-ins will have access to a SystemInfo object that is specific to the hardware/OS platform on which the plug-in is running. Once a plug-in obtains a SystemInfo object from its context (either
ResourceDiscoveryContext or ResourceContext), it can make calls to that object which will call down into the native libraries to obtain the requested data from the operating system. If there are no native libraries available, the SystemInfo will be backed with a pure Java implementation of some, but not all, of the methods defined in the SystemInfo interface (see the JavaSystemInfo implementation of that interface). The methods that are not supported by the pure Java implementation will throw an UnsupportedOperationException.
6.4.2. ProcessInfoQuery
The SystemInfo interface provides the ability to probe the operating system's process table. This is useful for ResourceDiscoveryComponent implementations because they can scan the list of running processes and attempt to determine if they can auto-detect a managed resource it is tasked to discover.
Through the use of the ProcessInfoQuery object, you can find processes that match a given set of criteria, defined by the Process Info Query Language (PIQL). You can even set pre-defined PIQL queries in your plug-in's descriptor via the process-scan tag to have the plug-in container scan the process table on behalf of your plug-in.
Note
Rather than repeat already documented information see ProcessInfoQuery http://git.fedorahosted.org/git/rhq/rhq.git?p=rhq/rhq.git;a=blob;hb=master;f=modules/core/native-system/src/main/java/org/rhq/core/system/pquery/ProcessInfoQuery.java to learn more about the syntax and usage of PIQL.
