org.osgi.service.startlevel
public interface StartLevel
A start level is defined to be a state of execution in which the Framework exists. StartLevel values are defined as unsigned integers with 0 (zero) being the state where the Framework is not launched. Progressively higher integral values represent progressively higher start levels. e.g. 2 is a higher start level than 1.
Access to the StartLevel service is protected by corresponding
ServicePermission
. In addition AdminPermission
is required to actually modify start level information.
Start Level support in the Framework includes the ability to control the beginning start level of the Framework, to modify the active start level of the Framework and to assign a specific start level to a bundle. How the beginning start level of a Framework is specified is implementation dependent. It may be a command line argument when invoking the Framework implementation.
When the Framework is first started it must be at start level zero. In this
state, no bundles are running. This is the initial state of the Framework
before it is launched.
When the Framework is launched, the Framework will enter start level one and
all bundles which are assigned to start level one and whose autostart setting
indicates the bundle should be started are started as described in the
Bundle.start
method. The Framework will continue to increase
the start level, starting bundles at each start level, until the Framework
has reached a beginning start level. At this point the Framework has
completed starting bundles and will then fire a Framework event of type
FrameworkEvent.STARTED
to announce it has completed its
launch.
Within a start level, bundles may be started in an order defined by the
Framework implementation. This may be something like ascending
Bundle.getBundleId
order or an order based upon dependencies
between bundles. A similar but reversed order may be used when stopping
bundles within a start level.
The StartLevel service can be used by management bundles to alter the active start level of the framework.
Version: $Revision: 1.19 $
Method Summary | |
---|---|
int | getBundleStartLevel(Bundle bundle)
Return the assigned start level value for the specified Bundle.
|
int | getInitialBundleStartLevel()
Return the initial start level value that is assigned to a Bundle when it
is first installed.
|
int | getStartLevel()
Return the active start level value of the Framework.
|
boolean | isBundleActivationPolicyUsed(Bundle bundle)
Returns whether the specified bundle's autostart setting indicates that
the activation policy declared in the bundle's manifest must be used.
|
boolean | isBundlePersistentlyStarted(Bundle bundle)
Returns whether the specified bundle's autostart setting indicates the
bundle must be started.
|
void | setBundleStartLevel(Bundle bundle, int startlevel)
Assign a start level value to the specified Bundle.
|
void | setInitialBundleStartLevel(int startlevel)
Set the initial start level value that is assigned to a Bundle when it is
first installed.
|
void | setStartLevel(int startlevel)
Modify the active start level of the Framework.
|
Parameters: bundle The target bundle.
Returns: The start level value of the specified Bundle.
Throws: java.lang.IllegalArgumentException If the specified bundle has been uninstalled.
Returns: The initial start level value for Bundles.
See Also: StartLevel
Returns: The active start level value of the Framework.
The autostart setting of a bundle indicates whether the bundle's declared activation policy is to be used when the bundle is started.
Parameters: bundle The bundle whose autostart setting is to be examined.
Returns: true
if the bundleb s autostart setting indicates
the activation policy declared in the manifest must be used.
false
if the bundle must be eagerly activated.
Throws: java.lang.IllegalArgumentException If the specified bundle has been uninstalled.
Since: 1.1
See Also: START_ACTIVATION_POLICY
The autostart setting of a bundle indicates whether the bundle is to be started when its start level is reached.
Parameters: bundle The bundle whose autostart setting is to be examined.
Returns: true
if the autostart setting of the bundle
indicates the bundle is to be started. false
otherwise.
Throws: java.lang.IllegalArgumentException If the specified bundle has been uninstalled.
See Also: START_TRANSIENT
The specified bundle will be assigned the specified start level. The start level value assigned to the bundle will be persistently recorded by the Framework.
If the new start level for the bundle is lower than or equal to the
active start level of the Framework and the bundle's autostart setting
indicates the bundle must be started, the Framework will start the
specified bundle as described in the Bundle method
using the START_TRANSIENT option. The
START_ACTIVATION_POLICY option must also be used if
isBundleActivationPolicyUsed returns true
for the bundle. The actual starting of this bundle must occur
asynchronously.
If the new start level for the bundle is higher than the active start level of the Framework, the Framework will stop the specified bundle as described in the Bundle method using the STOP_TRANSIENT option. The actual stopping of this bundle must occur asynchronously.
Parameters: bundle The target bundle. startlevel The new start level for the specified Bundle.
Throws: IllegalArgumentException If the specified bundle has been
uninstalled or if the specified start level is less than or equal
to zero, or the specified bundle is the system bundle. SecurityException If the caller does not have
AdminPermission[bundle,EXECUTE]
and the Java
runtime environment supports permissions.
The initial bundle start level will be set to the specified start level. The initial bundle start level value will be persistently recorded by the Framework.
When a Bundle is installed via BundleContext.installBundle
,
it is assigned the initial bundle start level value.
The default initial bundle start level value is 1 unless this method has been called to assign a different initial bundle start level value.
Thie method does not change the start level values of installed bundles.
Parameters: startlevel The initial start level for newly installed bundles.
Throws: IllegalArgumentException If the specified start level is less
than or equal to zero. SecurityException If the caller does not have
AdminPermission[System Bundle,STARTLEVEL]
and the
Java runtime environment supports permissions.
The Framework will move to the requested start level. This method will return immediately to the caller and the start level change will occur asynchronously on another thread.
If the specified start level is higher than the active start level, the Framework will continue to increase the start level until the Framework has reached the specified start level. At each intermediate start level value on the way to and including the target start level, the Framework must:
true
for the bundle.
FrameworkEvent.STARTLEVEL_CHANGED
to announce it has moved
to the specified start level.
If the specified start level is lower than the active start level, the Framework will continue to decrease the start level until the Framework has reached the specified start level. At each intermediate start level value on the way to and including the specified start level, the framework must:
FrameworkEvent.STARTLEVEL_CHANGED
to announce it has moved
to the specified start level.
If the specified start level is equal to the active start level, then no
bundles are started or stopped, however, the Framework must fire a
Framework event of type FrameworkEvent.STARTLEVEL_CHANGED
to announce it has finished moving to the specified start level. This
event may arrive before this method return.
Parameters: startlevel The requested start level for the Framework.
Throws: IllegalArgumentException If the specified start level is less
than or equal to zero. SecurityException If the caller does not have
AdminPermission[System Bundle,STARTLEVEL]
and the
Java runtime environment supports permissions.