org.apache.tomcat.util.modeler

Class Registry

java.lang.Object

org.apache.tomcat.util.modeler.Registry

All Implemented Interfaces:

MBeanRegistration, RegistryMBean

public class Registry
extends Object
implements RegistryMBean, MBeanRegistration

Registry for modeler MBeans. This is the main entry point into modeler. It provides methods to create and manipulate model mbeans and simplify their use. This class is itself an mbean. IMPORTANT: public methods not marked with @since x.x are experimental or internal. Should not be used.

Author:

Craig R. McClanahan, Costin Manolache

Constructor Summary

Constructors

Constructor and Description
Registry()

Method Summary

Modifier and Type	Method and Description
void	addManagedBean(ManagedBean bean) Add a new bean metadata to the set of beans known to this registry.
Object	convertValue(String type, String value) EXPERIMENTAL Convert a string to object, based on type.
ManagedBean	findManagedBean(Object bean, Class<?> beanClass, String type) Find or load metadata.
ManagedBean	findManagedBean(String name) Find and return the managed bean definition for the specified bean name, if any; otherwise return null.
int	getId(String domain, String name) Return an int ID for faster access.
MBeanServer	getMBeanServer() Factory method to create (if necessary) and return our MBeanServer instance.
MBeanOperationInfo	getMethodInfo(ObjectName oname, String opName) Find the operation info for a method
static Registry	getRegistry(Object key, Object guard) Factory method to create (if necessary) and return our Registry instance.
String	getType(ObjectName oname, String attName) Get the type of an attribute of the object, from the metadata.
void	invoke(List<ObjectName> mbeans, String operation, boolean failFirst) Invoke a operation on a list of mbeans.
List<ObjectName>	load(String sourceType, Object source, String param) Experimental.
void	loadDescriptors(String packageName, ClassLoader classLoader) Lookup the component descriptor in the package and in the parent packages.
void	postDeregister()
void	postRegister(Boolean registrationDone)
void	preDeregister()
ObjectName	preRegister(MBeanServer server, ObjectName name)
void	registerComponent(Object bean, ObjectName oname, String type) Register a component
void	registerComponent(Object bean, String oname, String type) Register a bean by creating a modeler mbean and adding it to the MBeanServer.
void	stop() Lifecycle method - clean up the registry metadata.
void	unregisterComponent(ObjectName oname) Unregister a component.
void	unregisterComponent(String oname) Unregister a component.

Methods inherited from class java.lang.Object

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

Constructor Detail

Registry

public Registry()

Method Detail

getRegistry

public static Registry getRegistry(Object key,
                                   Object guard)

Factory method to create (if necessary) and return our Registry instance. The current version uses a static - future versions could use the thread class loader.

Parameters:

key - Support for application isolation. If null, the context class loader will be used ( if setUseContextClassLoader is called ) or the default registry is returned.

guard - Prevent access to the registry by untrusted components

Returns:

the registry

Since:

1.1

stop

public void stop()

Lifecycle method - clean up the registry metadata. Called from resetMetadata().

Specified by:

stop in interface RegistryMBean

Since:

1.1

registerComponent

public void registerComponent(Object bean,
                              String oname,
                              String type)
                       throws Exception

Register a bean by creating a modeler mbean and adding it to the MBeanServer. If metadata is not loaded, we'll look up and read a file named "mbeans-descriptors.ser" or "mbeans-descriptors.xml" in the same package or parent. If the bean is an instance of DynamicMBean. it's metadata will be converted to a model mbean and we'll wrap it - so modeler services will be supported If the metadata is still not found, introspection will be used to extract it automatically. If an mbean is already registered under this name, it'll be first unregistered. If the component implements MBeanRegistration, the methods will be called. If the method has a method "setRegistry" that takes a RegistryMBean as parameter, it'll be called with the current registry.

Specified by:

registerComponent in interface RegistryMBean

Parameters:

bean - Object to be registered

oname - Name used for registration

type - The type of the mbean, as declared in mbeans-descriptors. If null, the name of the class will be used. This can be used as a hint or by subclasses.

Throws:

Exception - if a registration error occurred

Since:

1.1

unregisterComponent

public void unregisterComponent(String oname)

Unregister a component. We'll first check if it is registered, and mask all errors. This is mostly a helper.

Specified by:

unregisterComponent in interface RegistryMBean

Parameters:

oname - Name used for unregistration

Since:

1.1

invoke

public void invoke(List<ObjectName> mbeans,
                   String operation,
                   boolean failFirst)
            throws Exception

Invoke a operation on a list of mbeans. Can be used to implement lifecycle operations.

Specified by:

invoke in interface RegistryMBean

Parameters:

mbeans - list of ObjectName on which we'll invoke the operations

operation - Name of the operation ( init, start, stop, etc)

failFirst - If false, exceptions will be ignored

Throws:

Exception - Error invoking operation

Since:

1.1

getId

public int getId(String domain,
                 String name)

Return an int ID for faster access. Will be used for notifications and for other operations we want to optimize.

Specified by:

getId in interface RegistryMBean

Parameters:

domain - Namespace

name - Type of the notification

Returns:

An unique id for the domain:name combination

Since:

1.1

addManagedBean

public void addManagedBean(ManagedBean bean)

Add a new bean metadata to the set of beans known to this registry. This is used by internal components.

Parameters:

bean - The managed bean to be added

Since:

1.0

findManagedBean

public ManagedBean findManagedBean(String name)

Find and return the managed bean definition for the specified bean name, if any; otherwise return null.

Parameters:

name - Name of the managed bean to be returned. Since 1.1, both short names or the full name of the class can be used.

Returns:

the managed bean

Since:

1.0

getType

public String getType(ObjectName oname,
                      String attName)

Get the type of an attribute of the object, from the metadata.

Parameters:

oname - The bean name

attName - The attribute name

Returns:

null if metadata about the attribute is not found

Since:

1.1

getMethodInfo

public MBeanOperationInfo getMethodInfo(ObjectName oname,
                                        String opName)

Find the operation info for a method

Parameters:

oname - The bean name

opName - The operation name

Returns:

the operation info for the specified operation

unregisterComponent

public void unregisterComponent(ObjectName oname)

Unregister a component. This is just a helper that avoids exceptions by checking if the mbean is already registered

Parameters:

oname - The bean name

getMBeanServer

public MBeanServer getMBeanServer()

Factory method to create (if necessary) and return our MBeanServer instance.

Returns:

the MBean server

findManagedBean

public ManagedBean findManagedBean(Object bean,
                                   Class<?> beanClass,
                                   String type)
                            throws Exception

Find or load metadata.

Parameters:

bean - The bean

beanClass - The bean class

type - The registry type

Returns:

the managed bean

Throws:

Exception - An error occurred

convertValue

public Object convertValue(String type,
                           String value)

EXPERIMENTAL Convert a string to object, based on type. Used by several components. We could provide some pluggability. It is here to keep things consistent and avoid duplication in other tasks

Parameters:

type - Fully qualified class name of the resulting value

value - String value to be converted

Returns:

Converted value

load

public List<ObjectName> load(String sourceType,
                             Object source,
                             String param)
                      throws Exception

Experimental. Load descriptors.

Parameters:

sourceType - The source type

source - The bean

param - A type to load

Returns:

List of descriptors

Throws:

Exception - Error loading descriptors

registerComponent

public void registerComponent(Object bean,
                              ObjectName oname,
                              String type)
                       throws Exception

Register a component

Parameters:

bean - The bean

oname - The object name

type - The registry type

Throws:

Exception - Error registering component

loadDescriptors

public void loadDescriptors(String packageName,
                            ClassLoader classLoader)

Lookup the component descriptor in the package and in the parent packages.

Parameters:

packageName - The package name

classLoader - The class loader

preRegister

public ObjectName preRegister(MBeanServer server,
                              ObjectName name)
                       throws Exception

Specified by:

preRegister in interface MBeanRegistration

Throws:

Exception

postRegister

public void postRegister(Boolean registrationDone)

Specified by:

postRegister in interface MBeanRegistration

preDeregister

public void preDeregister()
                   throws Exception

Specified by:

preDeregister in interface MBeanRegistration

Throws:

Exception

postDeregister

public void postDeregister()

Specified by:

postDeregister in interface MBeanRegistration