org.directwebremoting.impl
Class DefaultContainer

java.lang.Object
  org.directwebremoting.impl.AbstractContainer
      org.directwebremoting.impl.DefaultContainer

All Implemented Interfaces:

Container

Direct Known Subclasses:

SpringContainer

public class DefaultContainer
extends AbstractContainer
implements Container

DefaultContainer is like a mini-IoC container for DWR. At least it is an IoC container by interface (check: no params that have anything to do with DWR), but it is hard coded specifically for DWR. If we want to make more of it we can later, but this is certainly not going to become a full blown IoC container.

Author:

Joe Walker [joe at getahead dot ltd dot uk]

Constructor Summary

DefaultContainer()

Method Summary

<T> void	addBean(java.lang.Class<T> base, T bean) Set the class that should be used to implement the given interface
<T> void	addImplementation(java.lang.Class<T> base, java.lang.Class<? extends T> implementation) Set the class that should be used to implement the given interface
<T> void	addImplementationOption(java.lang.Class<T> base, java.lang.Class<? extends T> implementation) Set the class that should be used to implement the given interface
void	addParameter(java.lang.String askFor, java.lang.Object valueParam) Add a parameter to the container as a possibility for injection
void	contextDestroyed() This should be called only by DwrListener.
void	contextDestroyed(java.util.Collection<java.lang.String> beanNames)
java.lang.Object	getBean(java.lang.String id) Get the contained instance of a bean/setting of a given name.
java.util.Collection<java.lang.String>	getBeanNames() Get a list of all the available beans.
java.lang.String	getParameter(java.lang.String name) Retrieve a previously set parameter
void	initializeBean(java.lang.Object bean) Sometimes we need to take a bean not created by the container, and inject it with the data that it would contain if it was created by the container.
<T> T	newInstance(java.lang.Class<T> type) Sometimes we need to create a bean as a one-off object and have it injected with settings by the container.
void	servletDestroyed() Should be called only by DwrServlet (or other servlet implementations).
void	servletDestroyed(java.util.Collection<java.lang.String> beanNames)
void	setupFinished() Called to indicate that we finished adding parameters.

Methods inherited from class org.directwebremoting.impl.AbstractContainer

getBean

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.directwebremoting.Container

getBean

Constructor Detail

DefaultContainer

public DefaultContainer()

Method Detail

addBean

public <T> void addBean(java.lang.Class<T> base,
                        T bean)

Set the class that should be used to implement the given interface

Parameters:

base - The interface to implement

bean - The new implementation

Throws:

ContainerConfigurationException - If the specified beans could not be used

addImplementation

public <T> void addImplementation(java.lang.Class<T> base,
                                  java.lang.Class<? extends T> implementation)

Set the class that should be used to implement the given interface

Parameters:

base - The interface to implement

implementation - The new implementation

Throws:

ContainerConfigurationException - If the specified beans could not be used

addImplementationOption

public <T> void addImplementationOption(java.lang.Class<T> base,
                                        java.lang.Class<? extends T> implementation)

Set the class that should be used to implement the given interface

Parameters:

base - The interface to implement

implementation - The new implementation

Throws:

ContainerConfigurationException - If the specified beans could not be used

addParameter

public void addParameter(java.lang.String askFor,
                         java.lang.Object valueParam)
                  throws ContainerConfigurationException

Add a parameter to the container as a possibility for injection

Parameters:

askFor - The key that will be looked up

valueParam - The value to be returned from the key lookup

Throws:

ContainerConfigurationException - If the specified beans could not be used

getParameter

public java.lang.String getParameter(java.lang.String name)

Retrieve a previously set parameter

Parameters:

name - The parameter name to retrieve

Returns:

The value of the specified parameter, or null if one is not set

setupFinished

public void setupFinished()

Called to indicate that we finished adding parameters. The thread safety of a large part of DWR depends on this function only being called from Servlet.init(javax.servlet.ServletConfig), where all the setup is done, and where we depend on the undocumented feature of all servlet containers that they complete the init process of a Servlet before they begin servicing requests.

See Also:

addParameter(String, Object)

newInstance

public <T> T newInstance(java.lang.Class<T> type)
              throws java.lang.InstantiationException,
                     java.lang.IllegalAccessException

Description copied from interface: Container

Sometimes we need to create a bean as a one-off object and have it injected with settings by the container. This does not make the object part of the container.

Specified by:

newInstance in interface Container

Parameters:

type - The type to get an instance of

Throws:

java.lang.InstantiationException

java.lang.IllegalAccessException

initializeBean

public void initializeBean(java.lang.Object bean)

Description copied from interface: Container

Sometimes we need to take a bean not created by the container, and inject it with the data that it would contain if it was created by the container. This does not make the object part of the container.

Specified by:

initializeBean in interface Container

Parameters:

bean - The object to inject.

getBean

public java.lang.Object getBean(java.lang.String id)

Description copied from interface: Container

Get the contained instance of a bean/setting of a given name.

Specified by:

getBean in interface Container

Parameters:

id - The type to get an instance of

Returns:

The object of the given type, or null if the object does not exist

getBeanNames

public java.util.Collection<java.lang.String> getBeanNames()

Description copied from interface: Container

Get a list of all the available beans. Implementation of this method is optional so it is valid for this method to return an empty collection, but to return Objects when queried directly using Container.getBean(String). This method should only be used for debugging purposes.

Specified by:

getBeanNames in interface Container

Returns:

A collection containing all the available bean names.

contextDestroyed

public void contextDestroyed()

Description copied from interface: Container

This should be called only by DwrListener. It requests all reverse ajax threads to stop.

GenericServlet.destroy() is called only when all connections are closed. If a DwrListener is configured then we can close down the connections in a timely way. All other tidy-up is done by Container.servletDestroyed() which will work even when a DwrListener has not been configured.

Specified by:

contextDestroyed in interface Container

See Also:

Container.servletDestroyed()

contextDestroyed

public void contextDestroyed(java.util.Collection<java.lang.String> beanNames)

servletDestroyed

public void servletDestroyed()

Description copied from interface: Container

Should be called only by DwrServlet (or other servlet implementations). It requests all other threads to stop, and any tidy-up that can be done after the context has been fully destroyed.

Specified by:

servletDestroyed in interface Container

See Also:

Container.contextDestroyed()

servletDestroyed

public void servletDestroyed(java.util.Collection<java.lang.String> beanNames)