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

java.lang.Object
  org.apache.sling.installer.api.tasks.InstallTask

All Implemented Interfaces:

java.lang.Comparable<InstallTask>

Direct Known Subclasses:

ChangeStateTask

public abstract class InstallTask
extends java.lang.Object
implements java.lang.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

static java.lang.String

ASYNC_ATTR_NAME Attribute which is set by the OSGi installer for asynchronous execution.

Constructor Summary

InstallTask(TaskResourceGroup erl)
Constructor for the task

Method Summary

int	compareTo(InstallTask o) All comparisons are based on getSortKey().
boolean	equals(java.lang.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 java.lang.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, java.lang.String alias) Set the finished state for the resource and the alias
java.lang.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 java.lang.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.

getResourceGroup

public TaskResourceGroup getResourceGroup()

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

setFinishedState

public void setFinishedState(ResourceState state)

Set the finished state for the resource.

Parameters:

state - The new state.

setFinishedState

public void setFinishedState(ResourceState state,
                             java.lang.String alias)

Set the finished state for the resource and the alias

Parameters:

state - The new state.

alias - The new alias

Since:

1.1

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public final boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public final int hashCode()

Overrides:

hashCode in class java.lang.Object

compareTo

public final int compareTo(InstallTask o)

All comparisons are based on getSortKey().

Specified by:

compareTo in interface java.lang.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