li.strolch.agent.api

Class StrolchComponent

java.lang.Object

li.strolch.agent.api.StrolchComponent

Direct Known Subclasses:

DefaultEnumHandler, DefaultPolicyHandler, DefaultRealmHandler, DefaultServiceHandler, DefaultStrolchPrivilegeHandler, SimplePostInitializer

public class StrolchComponent
extends Object

A StrolchComponent is a configurable extension to Strolch. Every major feature should be implemented as a StrolchComponent so that they can be easily added or removed from a Strolch runtime.

A StrolchComponent has access to the container and can perform different operations. They can be passive or active and their life cycle is bound to the container's life cycle

A StrolchComponent is registered in the Strolch configuration file and can have different configuration depending on the container's runtime environment

Author:

Robert von Burg

Field Summary

Fields

Modifier and Type	Field and Description
static String	COMPONENT_VERSION_PROPERTIES
protected static org.slf4j.Logger	logger

Constructor Summary

Constructors

Constructor and Description
StrolchComponent(ComponentContainer container, String componentName) Constructor which takes a reference to the container and the component's name under which it can be retrieved at runtime (although one mostly retrieves the component by interface class for automatic casting)

Method Summary

Modifier and Type	Method and Description
protected void	assertContainerStarted() Can be used by sub classes to assert that the entire container is started and thus ready to use, before any component methods are used
protected void	assertStarted() Can be used by sub classes to assert that the component is started and thus ready to use, before any component methods are used
void	destroy() Life cycle step destroy.
protected ComponentConfiguration	getConfiguration() The components current configuration dependent on the environment which is loaded
protected ComponentContainer	getContainer() Returns the reference to the container for sub classes
String	getName()
ComponentState	getState() Returns the current component's state
ComponentVersion	getVersion() Returns the version of this component.
void	initialize(ComponentConfiguration configuration) Life cycle step initialize.
protected void	runAs(String username, PrivilegedRunnable runnable) Performs the given PrivilegedRunnable as the given system user
protected void	runAs(String username, SystemAction action) Performs the given PrivilegedRunnable as the given system user
protected void	runAsAgent(PrivilegedRunnable runnable) Performs the given PrivilegedRunnable as the privileged system user StrolchConstants.SYSTEM_USER_AGENT
protected void	runAsAgent(SystemAction action) Performs the given PrivilegedRunnable as the given system user
protected <T> T	runAsAgentWithResult(PrivilegedRunnableWithResult<T> runnable) Performs the given PrivilegedRunnable as the privileged system user StrolchConstants.SYSTEM_USER_AGENT
protected <T> T	runAsAgentWithResult(SystemActionWithResult<T> action) Performs the given PrivilegedRunnable as the given system user
protected <T> T	runWithResult(String username, PrivilegedRunnableWithResult<T> runnable) Performs the given PrivilegedRunnable as the given system user
protected <T> T	runWithResult(String username, SystemActionWithResult<T> action) Performs the given PrivilegedRunnable as the given system user
void	setup(ComponentConfiguration configuration) Life cycle step setup.
void	start() Life cycle step start.
void	stop() Life cycle step stop.

Methods inherited from class java.lang.Object

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

Field Detail

COMPONENT_VERSION_PROPERTIES

public static final String COMPONENT_VERSION_PROPERTIES

See Also:

Constant Field Values

logger

protected static final org.slf4j.Logger logger

Constructor Detail

StrolchComponent

public StrolchComponent(ComponentContainer container,
                        String componentName)

Constructor which takes a reference to the container and the component's name under which it can be retrieved at runtime (although one mostly retrieves the component by interface class for automatic casting)

Parameters:

container - the container

componentName - the component name

Method Detail

getName

public String getName()

Returns:

the componentName

getState

public ComponentState getState()

Returns the current component's state

Returns:

the component's current state

getContainer

protected ComponentContainer getContainer()

Returns the reference to the container for sub classes

Returns:

the reference to the container

getConfiguration

protected ComponentConfiguration getConfiguration()

The components current configuration dependent on the environment which is loaded

Returns:

the component's configuration

assertStarted

protected void assertStarted()

Can be used by sub classes to assert that the component is started and thus ready to use, before any component methods are used

assertContainerStarted

protected void assertContainerStarted()

Can be used by sub classes to assert that the entire container is started and thus ready to use, before any component methods are used

setup

public void setup(ComponentConfiguration configuration)

Life cycle step setup. This is a very early step in the container's startup phase.

Parameters:

configuration -

initialize

public void initialize(ComponentConfiguration configuration)
                throws Exception

Life cycle step initialize. Here you would typically read configuration values

Parameters:

configuration -

Throws:

Exception

start

public void start()
           throws Exception

Life cycle step start. This is the last step of startup and is where threads and connections etc. would be prepared. Can also be called after stop, to restart the component.

Throws:

Exception

stop

public void stop()
          throws Exception

Life cycle step stop. This is the first step in the tearing down of the container. Stop all active threads and connections here. After stop is called, another start might also be called to restart the component.

Throws:

Exception

destroy

public void destroy()
             throws Exception

Life cycle step destroy. This is the last step in the tearing down of the container. Here you would release remaining resources and the component can not be started anymore afterwards

Throws:

Exception

runAs

protected void runAs(String username,
                     SystemAction action)
              throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

action - the action to perform

Throws:

PrivilegeException

runWithResult

protected <T> T runWithResult(String username,
                              SystemActionWithResult<T> action)
                       throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

action - the action to perform

Returns:

the result

Throws:

PrivilegeException

runAs

protected void runAs(String username,
                     PrivilegedRunnable runnable)
              throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

runnable - the runnable to perform

Throws:

PrivilegeException

runWithResult

protected <T> T runWithResult(String username,
                              PrivilegedRunnableWithResult<T> runnable)
                       throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

runnable - the runnable to perform

Returns:

the result

Throws:

PrivilegeException

runAsAgent

protected void runAsAgent(SystemAction action)
                   throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

action - the action to perform

Throws:

PrivilegeException

runAsAgentWithResult

protected <T> T runAsAgentWithResult(SystemActionWithResult<T> action)
                              throws PrivilegeException

Performs the given PrivilegedRunnable as the given system user

Parameters:

username - the name of the system user to perform the action as

action - the action to perform

Returns:

the result

Throws:

PrivilegeException

runAsAgent

protected void runAsAgent(PrivilegedRunnable runnable)
                   throws PrivilegeException

Performs the given PrivilegedRunnable as the privileged system user StrolchConstants.SYSTEM_USER_AGENT

Parameters:

runnable - the runnable to perform

Throws:

PrivilegeException

runAsAgentWithResult

protected <T> T runAsAgentWithResult(PrivilegedRunnableWithResult<T> runnable)
                              throws PrivilegeException

Performs the given PrivilegedRunnable as the privileged system user StrolchConstants.SYSTEM_USER_AGENT

Parameters:

runnable - the runnable to perform

Returns:

the result

Throws:

PrivilegeException

getVersion

public ComponentVersion getVersion()
                            throws IOException

Returns the version of this component. The version should be stored in the file COMPONENT_VERSION_PROPERTIES. See ComponentVersion for more information

Returns:

the component's version.

Throws:

IOException