org.springframework.jndi
Class JndiObjectFactoryBean

java.lang.Object
  org.springframework.jndi.JndiAccessor
      org.springframework.jndi.JndiLocatorSupport
          org.springframework.jndi.JndiObjectLocator
              org.springframework.jndi.JndiObjectFactoryBean

All Implemented Interfaces:

FactoryBean, InitializingBean

public class JndiObjectFactoryBean
extends JndiObjectLocator
implements FactoryBean

FactoryBean that looks up a JNDI object. Exposes the object found in JNDI for bean references, e.g. for data access object's "dataSource" property in case of a DataSource.

The typical usage will be to register this as singleton factory (e.g. for a certain JNDI-bound DataSource) in an application context, and give bean references to application services that need it.

The default behavior is to look up the JNDI object on startup and cache it. This can be customized through the "lookupOnStartup" and "cache" properties, using a JndiObjectTargetSource underneath. Note that you need to specify a "proxyInterface" in such a scenario, since the actual JNDI object type is not known in advance.

Of course, bean classes in a Spring environment may lookup e.g. a DataSource from JNDI themselves. This class simply enables central configuration of the JNDI name, and easy switching to non-JNDI alternatives. The latter is particularly convenient for test setups, reuse in standalone clients, etc.

Note that switching to e.g. DriverManagerDataSource is just a matter of configuration: Simply replace the definition of this FactoryBean with a DriverManagerDataSource definition!

Since:

22.05.2003

Author:

Juergen Hoeller

See Also:

setProxyInterface(java.lang.Class), setLookupOnStartup(boolean), setCache(boolean), JndiObjectTargetSource

Field Summary

Fields inherited from class org.springframework.jndi.JndiLocatorSupport

CONTAINER_PREFIX

Fields inherited from class org.springframework.jndi.JndiAccessor

logger

Constructor Summary

JndiObjectFactoryBean()

Method Summary

void	afterPropertiesSet() Look up the JNDI object and store it.
Object	getObject() Return the singleton JNDI object.
Class	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean	isSingleton() Is the bean managed by this factory a singleton or a prototype?
protected Object	lookupWithFallback() Lookup variant that that returns the specified "defaultObject" (if any) in case of lookup failure.
void	setCache(boolean cache) Set whether to cache the JNDI object once it has been located.
void	setDefaultObject(Object defaultObject) Specify a default object to fall back to if the JNDI lookup fails.
void	setLookupOnStartup(boolean lookupOnStartup) Set whether to look up the JNDI object on startup.
void	setProxyInterface(Class proxyInterface) Specify the proxy interface to use for the JNDI object.

Methods inherited from class org.springframework.jndi.JndiObjectLocator

getExpectedType, getJndiName, lookup, setExpectedType, setJndiName

Methods inherited from class org.springframework.jndi.JndiLocatorSupport

convertJndiName, isResourceRef, lookup, lookup, setResourceRef

Methods inherited from class org.springframework.jndi.JndiAccessor

getJndiEnvironment, getJndiTemplate, setJndiEnvironment, setJndiTemplate

Methods inherited from class java.lang.Object

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

Constructor Detail

JndiObjectFactoryBean

public JndiObjectFactoryBean()

Method Detail

setProxyInterface

public void setProxyInterface(Class proxyInterface)

Specify the proxy interface to use for the JNDI object. Needs to be specified because the actual JNDI object type is not known in advance in case of a lazy lookup.

Typically used in conjunction with "lookupOnStartup"=false and/or "cache"=false.

See Also:

setLookupOnStartup(boolean), setCache(boolean)

setLookupOnStartup

public void setLookupOnStartup(boolean lookupOnStartup)

Set whether to look up the JNDI object on startup. Default is "true".

Can be turned off to allow for late availability of the JNDI object. In this case, the JNDI object will be fetched on first access.

For a lazy lookup, a proxy interface needs to be specified.

See Also:

setProxyInterface(java.lang.Class), setCache(boolean)

setCache

public void setCache(boolean cache)

Set whether to cache the JNDI object once it has been located. Default is "true".

Can be turned off to allow for hot redeployment of JNDI objects. In this case, the JNDI object will be fetched for each invocation.

For hot redeployment, a proxy interface needs to be specified.

See Also:

setProxyInterface(java.lang.Class), setLookupOnStartup(boolean)

setDefaultObject

public void setDefaultObject(Object defaultObject)

Specify a default object to fall back to if the JNDI lookup fails. Default is none.

This can be an arbitrary bean reference or literal value. It is typically used for literal values in scenarios where the JNDI environment might define specific config settings but those are not required to be present.

Note: This is only supported for lookup on startup.

See Also:

setLookupOnStartup(boolean)

afterPropertiesSet

public void afterPropertiesSet()
                        throws IllegalArgumentException,
                               NamingException

Look up the JNDI object and store it.

Specified by:

afterPropertiesSet in interface InitializingBean

Overrides:

afterPropertiesSet in class JndiObjectLocator

Throws:

IllegalArgumentException

NamingException

lookupWithFallback

protected Object lookupWithFallback()
                             throws NamingException

Lookup variant that that returns the specified "defaultObject" (if any) in case of lookup failure.

Returns:

the located object, or the "defaultObject" as fallback

Throws:

NamingException - in case of lookup failure without fallback

See Also:

setDefaultObject(java.lang.Object)

getObject

public Object getObject()

Return the singleton JNDI object.

Specified by:

getObject in interface FactoryBean

Returns:

an instance of the bean (should not be null; a null value will be considered as an indication of incomplete initialization)

See Also:

FactoryBeanNotInitializedException

getObjectType

public Class getObjectType()

Description copied from interface: FactoryBean

Return the type of object that this FactoryBean creates, or null if not known in advance. This allows to check for specific types of beans without instantiating objects, for example on autowiring.

For a singleton, this should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:

getObjectType in interface FactoryBean

Returns:

the type of object that this FactoryBean creates, or null if not known at the time of the call

See Also:

ListableBeanFactory.getBeansOfType(java.lang.Class)

isSingleton

public boolean isSingleton()

Description copied from interface: FactoryBean

Is the bean managed by this factory a singleton or a prototype? That is, will getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

Specified by:

isSingleton in interface FactoryBean

Returns:

if this bean is a singleton

See Also:

FactoryBean.getObject()