Component (Knopflerfish OSGi 6.1.2 javadoc)

```
public interface Component
```
The Component interface represents a single component managed by the Service Component Runtime. Management agents may access the Component instances through the ScrService.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`STATE_ACTIVATING` The Component is currently being activated either because it has been enabled or because any dependency which was previously unsatisfied has become satisfied (value is 8).
`static int`	`STATE_ACTIVE` The Component has successfully been activated and is fully functional (value is 16).
`static int`	`STATE_DEACTIVATING` The Component is being deactivated either because it is being disabled or because a dependency is not satisfied any more (value is 128).
`static int`	`STATE_DESTROYED` Deprecated. as of version 1.2 this constant has been renamed to `STATE_DISPOSED`.
`static int`	`STATE_DISABLED` The Component has just been created and is still disabled or it has been disabled by calling the `disable()` method (value is 1).
`static int`	`STATE_DISABLING` The Component is being disabled (value is 1024).
`static int`	`STATE_DISPOSED` The Component has been disposed off and cannot be used any more (value is 256).
`static int`	`STATE_DISPOSING` The Component is being disposed off (value is 2048).
`static int`	`STATE_ENABLED` Deprecated. as of version 1.2 the enabled state is collapsed into the `STATE_UNSATISFIED` state. This status code is never returned from the `getState()` method.
`static int`	`STATE_ENABLING` The Component is being enabled (value is 512).
`static int`	`STATE_FACTORY` The Component is a Component Factory ready to create Component instances with the `ComponentFactory.newInstance(Dictionary)` method or (if enabled with the `ds.factory.enabled` configuration) to manage Component instances from configuration data received from the Configuration Admin Service (value is 64).
`static int`	`STATE_REGISTERED` The Component has successfully been activated but is a Delayed or Service Factory Component pending instantiation on first use (value is 32).
`static int`	`STATE_UNSATISFIED` The Component activation failed because any dependency is not satisfied (value is 4).

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`disable()` Disables this Component if it is enabled.
`void`	`enable()` Enables this Component if it is disabled.
`java.lang.String`	`getActivate()` Returns the name of the method to be called when the component is being activated.
`Bundle`	`getBundle()` Returns the `Bundle` declaring this component.
`java.lang.String`	`getClassName()` Returns the class name of the Component implementation.
`ComponentInstance`	`getComponentInstance()` Returns the `org.osgi.service.component.ComponentInstance` representing this component or `null` if this component is not been activated yet.
`java.lang.String`	`getConfigurationPolicy()` Reuturns the configuration policy declared in the component descriptor.
`java.lang.String`	`getDeactivate()` Returns the name of the method to be called when the component is being deactivated.
`java.lang.String`	`getFactory()` Returns the component factory name or `null` if this component is not defined as a component factory.
`long`	`getId()` Returns the component ID of this component.
`java.lang.String`	`getModified()` Returns the name of the method to be called when the component configuration has been updated or `null` if such a method is not declared in the component descriptor.
`java.lang.String`	`getName()` Returns the name of the component, which is also used as the service PID.
`java.util.Dictionary`	`getProperties()` Returns the properties of the Component.
`Reference[]`	`getReferences()` Returns an array of `Reference` instances representing the service references (or dependencies) of this Component.
`java.lang.String[]`	`getServices()` Returns an array of service names provided by this Component or `null` if the Component is not registered as a service.
`int`	`getState()` Returns the current state of the Component, which is one of the `STATE_*` constants defined in this interface.
`boolean`	`isActivateDeclared()` Returns `true` if the name of the method to be called on component activation (see `getActivate()` is declared in the component descriptor or not.
`boolean`	`isDeactivateDeclared()` Returns `true` if the name of the method to be called on component deactivation (see `getDeactivate()` is declared in the component descriptor or not.
`boolean`	`isDefaultEnabled()` Returns whether the Component is declared to be enabled initially.
`boolean`	`isImmediate()` Returns whether the Component is an Immediate or a Delayed Component.
`boolean`	`isServiceFactory()` Returns `true` if this component is a service factory.

- Field Detail
  - STATE_DISABLED
```
static final int STATE_DISABLED
```
    The Component has just been created and is still disabled or it has been disabled by calling the disable() method (value is 1).
    
    See Also:
    Constant Field Values
  - STATE_ENABLING
```
static final int STATE_ENABLING
```
    The Component is being enabled (value is 512). After the component has been enabled it enters the STATE_UNSATISFIED state.
    
    Since:
    
    1.2
    
    See Also:
    Constant Field Values
  - STATE_ENABLED
```
static final int STATE_ENABLED
```
    Deprecated. as of version 1.2 the enabled state is collapsed into the STATE_UNSATISFIED state. This status code is never returned from the getState() method.
    
    The Component has been enabled and is now going to be activated (value is 2).
    
    See Also:
    Constant Field Values
  - STATE_UNSATISFIED
```
static final int STATE_UNSATISFIED
```
    The Component activation failed because any dependency is not satisfied (value is 4).
    
    See Also:
    Constant Field Values
  - STATE_ACTIVATING
```
static final int STATE_ACTIVATING
```
    The Component is currently being activated either because it has been enabled or because any dependency which was previously unsatisfied has become satisfied (value is 8).
    
    See Also:
    Constant Field Values
  - STATE_ACTIVE
```
static final int STATE_ACTIVE
```
    The Component has successfully been activated and is fully functional (value is 16). This is the state of immediate components after successfull activation. Delayed and Service Factory Components enter this state when the service instance has actually be instantiated because the service has been acquired.
    
    See Also:
    Constant Field Values
  - STATE_REGISTERED
```
static final int STATE_REGISTERED
```
    The Component has successfully been activated but is a Delayed or Service Factory Component pending instantiation on first use (value is 32).
    
    See Also:
    Constant Field Values
  - STATE_FACTORY
```
static final int STATE_FACTORY
```
    The Component is a Component Factory ready to create Component instances with the ComponentFactory.newInstance(Dictionary) method or (if enabled with the ds.factory.enabled configuration) to manage Component instances from configuration data received from the Configuration Admin Service (value is 64).
    
    See Also:
    Constant Field Values
  - STATE_DEACTIVATING
```
static final int STATE_DEACTIVATING
```
    The Component is being deactivated either because it is being disabled or because a dependency is not satisfied any more (value is 128). After deactivation the Component enters the STATE_UNSATISFIED state.
    
    See Also:
    Constant Field Values
  - STATE_DISABLING
```
static final int STATE_DISABLING
```
    The Component is being disabled (value is 1024). After the component has been disabled it enters the STATE_DISABLED state.
    
    Since:
    
    1.2
    
    See Also:
    Constant Field Values
  - STATE_DISPOSING
```
static final int STATE_DISPOSING
```
    The Component is being disposed off (value is 2048). After the component has been disposed off it enters the STATE_DESTROYED state.
    
    Since:
    
    1.2
    
    See Also:
    Constant Field Values
  - STATE_DESTROYED
```
static final int STATE_DESTROYED
```
    Deprecated. as of version 1.2 this constant has been renamed to STATE_DISPOSED.
    
    The Component has been destroyed and cannot be used any more (value is 256). This state is only used when the bundle declaring the component is being stopped and all components have to be removed.
    
    See Also:
    Constant Field Values
  - STATE_DISPOSED
```
static final int STATE_DISPOSED
```
    The Component has been disposed off and cannot be used any more (value is 256). This state is used when the bundle declaring the component is being stopped and all components have to be removed. This status is also the final status of a component after the ComponentInstance.dispose() method has been called.
    
    Since:
    
    1.2
    
    See Also:
    Constant Field Values
- Method Detail
  - getId
```
long getId()
```
    Returns the component ID of this component. This ID is managed by the SCR. If the component is not currently enabled the ID might not be assigned to the component (yet) and this method will return -1 in this case.
  - getName
```
java.lang.String getName()
```
    Returns the name of the component, which is also used as the service PID. This method provides access to the name attribute of the component element.
  - getState
```
int getState()
```
    Returns the current state of the Component, which is one of the STATE_* constants defined in this interface.
  - getBundle
```
Bundle getBundle()
```
    Returns the Bundle declaring this component.
  - getFactory
```
java.lang.String getFactory()
```
    Returns the component factory name or null if this component is not defined as a component factory. This method provides access to the factory attribute of the component element.
  - isServiceFactory
```
boolean isServiceFactory()
```
    Returns true if this component is a service factory. This method returns the value of the serviceFactory attribute of the service element. If the component has no service element, this method returns false.
  - getClassName
```
java.lang.String getClassName()
```
    Returns the class name of the Component implementation. This method provides access to the class attribute of the implementation element.
  - isDefaultEnabled
```
boolean isDefaultEnabled()
```
    Returns whether the Component is declared to be enabled initially. This method provides access to the enabled attribute of the component element.
  - isImmediate
```
boolean isImmediate()
```
    Returns whether the Component is an Immediate or a Delayed Component. This method provides access to the immediate attribute of the component element.
  - getServices
```
java.lang.String[] getServices()
```
    Returns an array of service names provided by this Component or null if the Component is not registered as a service. This method provides access to the interface attributes of the provide elements.
  - getProperties
```
java.util.Dictionary getProperties()
```
    Returns the properties of the Component. The Dictionary returned is a private copy of the actual properties and contains the same entries as are used to register the Component as a service and are returned by the ComponentContext.getProperties() method.
  - getReferences
```
Reference[] getReferences()
```
    Returns an array of Reference instances representing the service references (or dependencies) of this Component. If the Component has no references, null is returned.
  - getComponentInstance
```
ComponentInstance getComponentInstance()
```
    Returns the org.osgi.service.component.ComponentInstance representing this component or null if this component is not been activated yet.
    
    Since:
    
    1.2
  - getActivate
```
java.lang.String getActivate()
```
    Returns the name of the method to be called when the component is being activated.
    This method never returns null, that is, if this method is not declared in the component descriptor this method returns the default value activate.
    
    Since:
    
    1.2
  - isActivateDeclared
```
boolean isActivateDeclared()
```
    Returns true if the name of the method to be called on component activation (see getActivate() is declared in the component descriptor or not.
    For a component declared in a Declarative Services 1.0 descriptor, this method always returns false.
    
    Since:
    
    1.2
  - getDeactivate
```
java.lang.String getDeactivate()
```
    Returns the name of the method to be called when the component is being deactivated.
    This method never returns null, that is, if this method is not declared in the component descriptor this method returns the default value deactivate.
    
    Since:
    
    1.2
  - isDeactivateDeclared
```
boolean isDeactivateDeclared()
```
    Returns true if the name of the method to be called on component deactivation (see getDeactivate() is declared in the component descriptor or not.
    For a component declared in a Declarative Services 1.0 descriptor, this method always returns false.
    
    Since:
    
    1.2
  - getModified
```
java.lang.String getModified()
```
    Returns the name of the method to be called when the component configuration has been updated or null if such a method is not declared in the component descriptor.
    For a component declared in a Declarative Services 1.0 descriptor, this method always returns null.
    
    Since:
    
    1.2
  - getConfigurationPolicy
```
java.lang.String getConfigurationPolicy()
```
    Reuturns the configuration policy declared in the component descriptor. If the component descriptor is a Declarative Services 1.0 descriptor or not configuration poliy has been declared, the default value optional is returned.
    The returned string is one of the three policies defined in the Declarative Services specification 1.1:
    
    optional
    
    Configuration from the Configuration Admin service is supplied to the component if available. Otherwise the component is activated without Configuration Admin configuration. This is the default value reflecting the behaviour of Declarative Services 1.0
    
    require
    
    Configuration is required. The component remains unsatisfied until configuartion is available from the Configuration Admin service.
    
    ignore
    
    Configuration is ignored. No Configuration Admin service configuration is supplied to the component.
    
    Since:
    
    1.2
  - enable
```
void enable()
```
    Enables this Component if it is disabled. If the Component is not currently disabled this method has no effect. If the Component is destroyed, this method throws an IllegalStateException.
    
    Throws:
    
    java.lang.IllegalStateException - If the Component is destroyed.
  - disable
```
void disable()
```
    Disables this Component if it is enabled. If the Component is already disabled this method has no effect. If the Component is destroyed, this method throws an IllegalStateException.
    
    Throws:
    
    java.lang.IllegalStateException - If the Component is destroyed.

Interface Component

Field Summary

Method Summary

Field Detail

STATE_DISABLED

STATE_ENABLING

STATE_ENABLED

STATE_UNSATISFIED

STATE_ACTIVATING

STATE_ACTIVE

STATE_REGISTERED

STATE_FACTORY

STATE_DEACTIVATING

STATE_DISABLING

STATE_DISPOSING

STATE_DESTROYED

STATE_DISPOSED

Method Detail

getId

getName

getState

getBundle

getFactory

isServiceFactory

getClassName

isDefaultEnabled

isImmediate

getServices

getProperties

getReferences

getComponentInstance

getActivate

isActivateDeclared

getDeactivate

isDeactivateDeclared

getModified

getConfigurationPolicy

enable

disable