framework.java

OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上

   * <p>If the Framework is already started, this method does nothing.
   * If the Framework is not started, this method will:
   * <ol>
   * <li>Enable event handling. At this point, events can be delivered to
   * listeners.</li>
   * <li>Attempt to start all bundles marked for starting as described in the
   * {@link Bundle#start} method.
   * Reports any exceptions that occur during startup using
   * <code>FrameworkErrorEvents</code>.</li>
   * <li>Set the state of the Framework to <i>active</i>.</li>
   * <li>Broadcasting a <code>FrameworkEvent</code> through the
   * <code>FrameworkListener.frameworkStarted</code> method.</li>
   * </ol></p>
   *
   * <p>If this Framework is not launched, it can still install,
   * uninstall, start and stop bundles.  (It does these tasks without
   * broadcasting events, however.)  Using Framework without launching
   * it allows for off-line debugging of the Framework.</p>
   *
   * @param startBundle If it is specified with a value larger than 0,
   *                    then the bundle with that id is started.
   *                    Otherwise start all suspended bundles.
   */
  public void launch(long startBundle) throws BundleException {
    if (!active) {
      active = true;
      if (startBundle > 0) {
	startBundle(startBundle);
      } else {
	for (Iterator i = storage.getStartOnLaunchBundles().iterator(); i.hasNext(); ) {
	  Bundle b = bundles.getBundle((String)i.next());
	  try {
	    b.start();
	  } catch (BundleException be) {
	    listeners.frameworkError(b, be);
	  }
	}
      }
      systemBundle.systemActive();

      // start level open is delayed to this point to 
      // correctly work at restart
      if(startLevelService != null) {
        startLevelService.open();
      }

      listeners.frameworkEvent(new FrameworkEvent(FrameworkEvent.STARTED, systemBundle, null));
    }
  }


  /**
   * Stop this Framework, suspending all started contexts.
   * This method suspends all started contexts so that they can be
   * automatically restarted when this Framework is next launched.
   *
   * <p>If the framework is not started, this method does nothing.
   * If the framework is started, this method will:
   * <ol>
   * <li>Set the state of the Framework to <i>inactive</i>.</li>
   * <li>Suspended all started bundles as described in the
   * {@link Bundle#stop} method except that the persistent
   * state of the bundle will continue to be started.
   * Reports any exceptions that occur during stopping using
   * <code>FrameworkErrorEvents</code>.</li>
   * <li>Disable event handling.</li>
   * </ol></p>
   *
   */
  public void shutdown() {
    if (active) {
      // No shuttingdown event specified
      // listeners.frameworkChanged(new FrameworkEvent(FrameworkEvent.SHUTTING_DOWN));
      active = false;
      List slist = storage.getStartOnLaunchBundles();
      shuttingdown = true;
      if(startLevelService != null) {
	startLevelService.close();
      }
      systemBundle.systemShuttingdown();
      // Stop bundles, in reverse start order
      for (int i = slist.size()-1; i >= 0; i--) {
	Bundle b = bundles.getBundle((String)slist.get(i));
	try {
	  if(b != null) {
	    synchronized (b) {
	      if (b.getState() == Bundle.ACTIVE) {
		b.stop();
	      }
	    }
	  }
	} catch (BundleException be) {
	  listeners.frameworkEvent(new FrameworkEvent(FrameworkEvent.ERROR, b, be));
	}
      }
      shuttingdown = false; 
      // Purge any unrefreshed bundles
      BundleImpl [] all = bundles.getBundles();
      for (int i = 0; i < all.length; i++) {
	all[i].purge();
      }
    }
  }


  /**
   * Install a bundle from the given location.
   *
   * @param location The location identifier of the bundle to install.
   * @param in The InputStream from which the bundle will be read.
   * @return The BundleImpl object of the installed bundle.
   * @exception BundleException If the install failed.
   */
  public long installBundle(String location, InputStream in) throws BundleException {
    return bundles.install(location, in).id;
  }


  /**
   * Start a bundle.
   *
   * @param id Id of bundle to start.
   * @exception BundleException If start failed.
   */
  public void startBundle(long id) throws BundleException {
    BundleImpl b = bundles.getBundle(id);
    if (b != null) {
      b.start();
    } else {
      throw new BundleException("No such bundle: " + id);
    }
  }


  /**
   * Stop a bundle.
   *
   * @param id Id of bundle to stop.
   * @exception BundleException If stop failed.
   */
  public void stopBundle(long id) throws BundleException {
    BundleImpl b = bundles.getBundle(id);
    if (b != null) {
      b.stop();
    } else {
      throw new BundleException("No such bundle: " + id);
    }
  }


  /**
   * Uninstall a bundle.
   *
   * @param id Id of bundle to stop.
   * @exception BundleException If uninstall failed.
   */
  public void uninstallBundle(long id) throws BundleException {
    BundleImpl b = bundles.getBundle(id);
    if (b != null) {
      b.uninstall();
    } else {
      throw new BundleException("No such bundle: " + id);
    }
  }


  /**
   * Update a bundle.
   *
   * @param id Id of bundle to update.
   * @exception BundleException If update failed.
   */
  public void updateBundle(long id) throws BundleException {
    BundleImpl b = bundles.getBundle(id);
    if (b != null) {
      b.update();
    } else {
      throw new BundleException("No such bundle: " + id);
    }
  }


  /**
   * Retrieve location of the bundle that has the given
   * unique identifier.
   *
   * @param id The identifier of the bundle to retrieve.
   * @return A location as a string, or <code>null</code>
   * if the identifier doesn't match any installed bundle.
   */
  public String getBundleLocation(long id) {
    BundleImpl b = bundles.getBundle(id);
    if (b != null) {
      return b.location;
    } else {
      return null;
    }
  }

  /**
   * Retrieve bundle id of the bundle that has the given
   * unique location.
   *
   * @param location The location of the bundle to retrieve.
   * @return The unique identifier of the bundle, or <code>-1</code>
   * if the location doesn't match any installed bundle.
   */
  public long getBundleId(String location) {
    BundleImpl b = bundles.getBundle(location);
    if (b != null) {
      return b.id;
    } else {
      return -1;
    }
  }

  /**
   * Check that we have admin permission.
   *
   * @exception SecurityException if we don't have admin permission.
   */
  void checkAdminPermission() {
    if (bPermissions) {
      AccessController.checkPermission(ADMIN_PERMISSION);
    }
  }

  /**
   * Get private bundle data storage file handle.
   */
  FileTree getDataStorage() {
    return dataStorage;
  }

  /**
   * Check if an execution environment string is accepted
   */
  boolean isValidEE(String ee) {

    if(ee == null || "".equals(ee)) {
      return true;
    }

    String fwEE = System.getProperty(Constants.FRAMEWORK_EXECUTIONENVIRONMENT);

    if(fwEE == null) {
      eeCacheSet.clear();
    } else {
      if(!fwEE.equals(eeCache)) {
	eeCacheSet.clear();

	String[] l = Util.splitwords(fwEE, ",", '\"');
	for(int i = 0 ; i < l.length; i++) {
	  eeCacheSet.add(l[i]);
	}
      }
    }
    eeCache = fwEE;

    String[] eel   = Util.splitwords(ee, ",", '\"');
    
    for(int i = 0 ; i < eel.length; i++) {
      if(eeCacheSet.contains(eel[i])) {
	return true;
      }
    }

    return false;
  }


  // Cached value of 
  // System.getProperty(Constants.FRAMEWORK_EXECUTIONENVIRONMENT)
  // Used and updated by isValidEE()
  Set    eeCacheSet = new HashSet();
  String eeCache = null;

  //
  // Static package methods
  //

  /**
   * Retrieve the value of the named framework property.
   *
   */
  public static String getProperty(String key) {
    if (Constants.FRAMEWORK_VERSION.equals(key)) {
      // The version of the framework. 
      return SPEC_VERSION;
    } else if (Constants.FRAMEWORK_VENDOR.equals(key)) {
      // The vendor of this framework implementation. 
      return "Knopflerfish";
    } else if (Constants.FRAMEWORK_LANGUAGE.equals(key)) {
      // The language being used. See ISO 639 for possible values. 
      return Locale.getDefault().getLanguage();
    } else if (Constants.FRAMEWORK_OS_NAME.equals(key)) {
      // The name of the operating system of the hosting computer. 
      return osName;
    } else if (Constants.FRAMEWORK_OS_VERSION.equals(key)) {
      // The version number of the operating system of the hosting computer. 
      return osVersion;
    } else if (Constants.FRAMEWORK_PROCESSOR.equals(key)) {
      // The name of the processor of the hosting computer. 
      return osArch;
    } else if (Constants.FRAMEWORK_EXECUTIONENVIRONMENT.equals(key)) {
      // The name of the fw execution environment
      return System.getProperty(Constants.FRAMEWORK_EXECUTIONENVIRONMENT);
    } else {
      return System.getProperty(key);
    }
  }

  /**
   * Get the bundle context used by the system bundle.
   */
  public BundleContext getSystemBundleContext() {
    return (BundleContext)
      AccessController.doPrivileged(new  PrivilegedAction() {
	  public Object run() {
	    return systemBC;
	  }});
  }
}