Package org.apache.sling.installer.api.tasks

Class InstallTask

java.lang.Object

org.apache.sling.installer.api.tasks.InstallTask

All Implemented Interfaces:

Comparable<InstallTask>

Direct Known Subclasses:

ChangeStateTask

public abstract class InstallTask
extends Object
implements Comparable<InstallTask>

Base class for tasks that can be executed by the OsgiInstaller. The task is invoked by the installer through the execute(InstallationContext) method. During execution the task should use the setFinishedState(ResourceState) or setFinishedState(ResourceState, String) method once the task is performed or the task decided that the task can never be performed. If the task needs to be retried, the implementation should just not alter the state at all. The installer will invoke the tasks at a later time again for retrying.

Field Summary

Fields

Modifier and Type	Field	Description
static String	ASYNC_ATTR_NAME	Attribute which is set by the OSGi installer for asynchronous execution.

Constructor Summary

Constructors

Constructor	Description
InstallTask(TaskResourceGroup erl)	Constructor for the task

Method Summary

Modifier and Type	Method	Description
int	compareTo(InstallTask o)	All comparisons are based on getSortKey().
boolean	equals(Object o)
abstract void	execute(InstallationContext ctx)	This is the heart of the task - it performs the actual task.
TaskResource	getResource()	Return the corresponding resource - depending on the task this might be null.
TaskResourceGroup	getResourceGroup()	Return the corresponding resource - depending on the task this might be null.
abstract String	getSortKey()	Tasks are sorted according to this key.
int	hashCode()
boolean	isAsynchronousTask()	If this an asynchronous task it should return true The OSGi installer will set the attribute ASYNC_ATTR_NAME with an integer value.
void	setFinishedState(ResourceState state)	Set the finished state for the resource.
void	setFinishedState(ResourceState state, String alias)	Set the finished state for the resource and the alias
void	setFinishedState(ResourceState state, String alias, String error)	Set the finish state for the active resource and alias (may be null).
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

ASYNC_ATTR_NAME

public static final String ASYNC_ATTR_NAME

Attribute which is set by the OSGi installer for asynchronous execution. The value of the attribute is an Integer which is increased on each async call, it starts with the value 1.

See Also:

Constant Field Values

Constructor Detail

InstallTask

public InstallTask(TaskResourceGroup erl)

Constructor for the task

Parameters:

erl - The resource group or null.

Method Detail

getResource

public TaskResource getResource()

Return the corresponding resource - depending on the task this might be null.

Returns:

The task resource or null.

getResourceGroup

public TaskResourceGroup getResourceGroup()

Return the corresponding resource - depending on the task this might be null.

Returns:

The task resource group or null.

execute

public abstract void execute(InstallationContext ctx)

This is the heart of the task - it performs the actual task.

Parameters:

ctx - The installation context.

getSortKey

public abstract String getSortKey()

Tasks are sorted according to this key. Therefore this key must uniquely identify this task. A typical sort key contains the entity id of the resource in execution.

Returns:

The sorting key.

setFinishedState

public void setFinishedState(ResourceState state)

Set the finished state for the resource.

Parameters:

state - The new state.

setFinishedState

public void setFinishedState(ResourceState state,
                             String alias)

Set the finished state for the resource and the alias

Parameters:

state - The new state.

alias - The new alias

Since:

1.1

setFinishedState

public void setFinishedState(ResourceState state,
                             String alias,
                             String error)

Set the finish state for the active resource and alias (may be null). In addition set an error text (may be null).

Parameters:

state - The new state.

alias - The new alias (may be null).

error - An error text (may be null).

Since:

1.4

See Also:

setFinishedState(ResourceState)

toString

public String toString()

Overrides:

toString in class Object

equals

public final boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

compareTo

public final int compareTo(InstallTask o)

All comparisons are based on getSortKey().

Specified by:

compareTo in interface Comparable<InstallTask>

isAsynchronousTask

public boolean isAsynchronousTask()

If this an asynchronous task it should return true The OSGi installer will set the attribute ASYNC_ATTR_NAME with an integer value. The next time, after the asynchronous task has been run and the OSGi installer has restarted, this attribute will be set on the resource. Asynchronous tasks should only be used for tasks which require the OSGi installer to stop and force it to restart, like a bundle update of the installer itself or a system update. The OSGi installer stops itself for an asynchronous task and is not able to restart itself!

Returns:

If this is a async request, true otherwise false

Since:

1.3