Module org.apache.jena.core
Package org.apache.jena.sys

Class JenaSystem

java.lang.Object
org.apache.jena.sys.JenaSystem
public class JenaSystem extends Object
Jena "system" - simple controls for ensuring components are loaded and initialized.

All initialization should be concurrent and thread-safe. In particular, some subsystems need initialization in some sort of order (e.g. ARQ before TDB).

This is achieved by "levels": levels less than 500 are considered "Jena system levels" and are reserved.

  • 0 - reserved
  • 10 - jena-core
  • 20 - RIOT
  • 30 - ARQ
  • 40 - TDB
  • 50-100 - Other Jena system modules.
  • 101 - Fuseki
  • 102-9998 - Application
  • 9999 - other
See also the notes on Jena initialization.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static boolean
    DEBUG_INIT
    Development support - flag to enable output during initialization.

  • Constructor Summary

    Constructors
    Constructor
    Description
    JenaSystem()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static void
    init()
    Initialize Jena.
    static void
    init(boolean withTracing)
    Initialize Jena.
    static void
    logLifecycle(String fmt, Object... args)
    Output a debugging message if DEBUG_INIT is set
    static void
    shutdown()
     

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • DEBUG_INIT

      public static boolean DEBUG_INIT
      Development support - flag to enable output during initialization. Output to System.err, not a logger to avoid the risk of recursive initialization.

  • Constructor Details

    • JenaSystem

      public JenaSystem()

  • Method Details

    • logLifecycle

      public static void logLifecycle(String fmt, Object... args)
      Output a debugging message if DEBUG_INIT is set

    • init

      public static void init()
      Initialize Jena. This call can be made several times. Only the first causes the one-time initialization.

    • init

      public static void init(boolean withTracing)
      Initialize Jena. This call can be made several times. Only the first causes the one-time initialization.

      Optionally, output initialization steps (prints to stderr).

    • shutdown

      public static void shutdown()