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Class com.sun.jaw.impl.agent.services.persistent.PersistentRepSrv

java.lang.Object
   |
   +----com.sun.jaw.impl.agent.services.light.RepositorySrv
           |
           +----com.sun.jaw.impl.agent.services.persistent.PersistentRepSrv

public class PersistentRepSrv
extends RepositorySrv
implements MoRepSrvIf, ResolveLoaderIf

This class provides an implementation of a persistent repository. The repository contains a mixture of volatile and persistent m-beans. The repository stores volatile m-beans in memory. It stores persistent m-beans in a flat-file database. The framework should be the first object to register with the repository, enabling the synchronization of m-beans with the current framework. To enable framework synchronization the repository has to be a trusted class. i.e. It must be loaded by the premordial(system) classloader. Each persistent m-bean is stored as a serialized Java object. For each persistent m-bean, the repository stores:

The object name of the m-bean
The serialized m-bean
The object name of the class loader that loaded the m-bean when it was instantiated

The repository stores the object name of the class loader to enable it to locate the class loader when an agent deserializes the m-bean. To locate a class loader, the repository internally invokes these methods:

retrieveClassLoaderName
resolveClassLoader

Note - Use the setConfig method to configure the repository before trying to register any m-beans with it.

See Also:: MoRepSrvIf, ObjectInputStream, ObjectOutputStream, Serializable, Externalizable

PersistentRepSrv(): Default constructor.

contains(Object): Verifies whether a singleton m-bean is registered with the repository.
contains(ObjectName): Verifies whether an m-bean is registered with the repository.
getDomain(): Gets the domain of the repository.
getNbElements(): Gets the number of m-beans registered with the repository.
getObject(ObjectName, QueryExp): Gets handles on m-beans controlled by the repository.
isPersistent(): Indicates whether the repository offers persistent storage.
isQuerySrv(): Indicates whether the repository supports filtering.
register(Object, ObjectName): Invoked by the core management framework to register a volatile m-bean with the repository.
registerDB(Object, ObjectName): Invoked by the core management framework to register a persistent m-bean with the repository.
resolveClassLoader(ObjectName): Gets the class loader associated with an m-bean that is being deserialized.
retrieve(ObjectName): Retrieves an m-bean from the repository.
retrieveClassLoaderName(ClassLoader): Gets the object name of a class loader.
setConfig(Vector): Configures the repository and starts the database.
setDomain(String): Sets the domain of the repository.
stop(): Stop the repository and release allocated resources.
unregister(Object): Removes a singleton m-bean from the repository.
unregister(ObjectName): Removes an m-bean from the repository.
update(Object, ObjectName): Updates an m-bean registered with the repository.

PersistentRepSrv

 public PersistentRepSrv()

Default constructor.

setConfig

 public void setConfig(Vector params)

Configures the repository and starts the database.

The configuration parameters must be specified in the following order:

The base directory of the database. By default it is the current directory of the agent.
The name of the database. The repository creates a directory with this name in the base directory. The file that contains the database is written to the directory created. The name of the database is default.db by default.

All parameters are String objects or null if not specified. If the parameter vector is empty or null, default values are used.

Parameters:: params - A vector containing the configuration parameters of the repository.
Overrides:: setConfig in class RepositorySrv

isQuerySrv

 public boolean isQuerySrv()

Indicates whether the repository supports filtering. If the repository does not support filtering, the core management framework will perform filtering for the repository.

Returns:: True if the filtering is supported, false otherwise.
Overrides:: isQuerySrv in class RepositorySrv

isPersistent

 public boolean isPersistent()

Indicates whether the repository offers persistent storage.

Returns:: True if the repository offers persistent storage, false otherwise.
Overrides:: isPersistent in class RepositorySrv

contains

 public boolean contains(ObjectName name)

Verifies whether an m-bean is registered with the repository.

Parameters:: name - The object name of the m-bean.
Returns:: True if the m-bean is registered with the repository, false otherwise.
Overrides:: contains in class RepositorySrv

retrieve

 public Object retrieve(ObjectName name)

Retrieves an m-bean from the repository.

Parameters:: name - The object name of the m-bean to be retrieved.
Returns:: The retrieved m-bean, or null if it could not be retrieved.
Overrides:: retrieve in class RepositorySrv

contains

 public boolean contains(Object object)

Verifies whether a singleton m-bean is registered with the repository. A singleton m-bean has no search key in its object name and is, therefore, the only instance of the class permitted in the domain.

Parameters:: object - The m-bean.
Returns:: True if the m-bean is registered with the repository, false otherwise.
Overrides:: contains in class RepositorySrv

registerDB

 public void registerDB(Object object,
                        ObjectName name) throws InstanceAlreadyExistException

Invoked by the core management framework to register a persistent m-bean with the repository.

Parameters:: object - The m-bean to be registered.; name - The object name with which the m-bean is to be registered.
Throws: InstanceAlreadyExistException: The m-bean is already registered in the object repository.
Overrides:: registerDB in class RepositorySrv

register

 public void register(Object object,
                      ObjectName name) throws InstanceAlreadyExistException

Invoked by the core management framework to register a volatile m-bean with the repository.

Parameters:: object - The m-bean to be registered.; name - The object name with which the m-bean is to be registered.
Throws: InstanceAlreadyExistException: The m-bean is already registered in the repository.
Overrides:: register in class RepositorySrv

update

 public void update(Object object,
                    ObjectName name) throws InstanceNotFoundException

Updates an m-bean registered with the repository.

Parameters:: object - The new instance of the m-bean.; name - The object name of the m-bean to be updated.
Throws: InstanceNotFoundException: The specified m-bean was not found in the repository.
Overrides:: update in class RepositorySrv

unregister

 public void unregister(ObjectName name) throws InstanceNotFoundException

Removes an m-bean from the repository.

Parameters:: name - The object name of the m-bean to be removed.
Throws: InstanceNotFoundException: The specified m-bean was not found in the repository.
Overrides:: unregister in class RepositorySrv

unregister

 public void unregister(Object object) throws InstanceNotFoundException

Removes a singleton m-bean from the repository. A singleton m-bean has no search key in its object name and is, therefore, the only instance of the class permitted in the domain.

Parameters:: object - The m-bean to be removed from the repository.
Throws: InstanceNotFoundException: The specified m-bean was not found in the repository.
Overrides:: unregister in class RepositorySrv

getObject

 public Vector getObject(ObjectName name,
                         QueryExp query)

Gets handles on m-beans controlled by the repository.

Parameters:: name - An object name that specifies the m-beans to be selected.; query - A query to be applied to the selected m-beans.
Returns:: A list of named objects corresponding to the selected m-beans.
Overrides:: getObject in class RepositorySrv

getNbElements

 public Integer getNbElements()

Gets the number of m-beans registered with the repository.

Returns:: The number of m-beans registered with the repository.
Overrides:: getNbElements in class RepositorySrv

getDomain

 public String getDomain()

Gets the domain of the repository.

Returns:: The domain of the repository.
Overrides:: getDomain in class RepositorySrv

setDomain

 public void setDomain(String domain)

Sets the domain of the repository.

Overrides:: setDomain in class RepositorySrv

resolveClassLoader

 public ClassLoader resolveClassLoader(ObjectName aloader)

Gets the class loader associated with an m-bean that is being deserialized. It is the class loader that loaded the m-bean when it was instantiated. The repository internally invokes this method when the m-bean is deserialized. The method searches the repository to find the class loader.

Parameters:: aloader - The object name of the class loader.
Returns:: The required class loader, or null if the class loader could not be retrieved.

retrieveClassLoaderName

 public ObjectName retrieveClassLoaderName(ClassLoader loader)

Gets the object name of a class loader. The repository internally invokes this method when an m-bean is deserialized. The method analyzes the specified loader to find the method getLoaderName with the following signature:

ObjectName getLoaderName()

The getLoaderName method found is invoked with no parameters and returns the object name of the class loader.

Parameters:: loader - The class loader.
Returns:: The object name of the class loader, or null if the object name could not be retrieved.

stop

 public void stop()

Stop the repository and release allocated resources.

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