org.directwebremoting.impl
Class ContainerUtil

java.lang.Object
  org.directwebremoting.impl.ContainerUtil

public class ContainerUtil
extends java.lang.Object

An abstraction of all the common servlet operations that are required to host a DWR service that depends on the servlet spec. It would be good to have a base class for all servlet operations, however lack of MI prevents us from doing this.

Author:

Joe Walker [joe at getahead dot ltd dot uk]

Field Summary

static java.lang.String	ATTRIBUTE_CONTAINER_LIST The name under which we publish all Containers.
static java.lang.String	DEFAULT_SERVERCONTEXT_NAME We store a single ServerContext in the contextMap under this name.
static java.lang.String	INIT_CONFIG Init parameter: Set a dwr.xml config file.
static java.lang.String	INIT_CUSTOM_CONFIGURATOR Init parameter: If you wish to use a custom configurator, place its class name here
static java.lang.String	INIT_LOGLEVEL Init parameter: If we are doing Servlet.log logging, to what level?
static java.lang.String	INIT_SKIP_DEFAULT Init parameter: Skip reading the default config file if none are specified.

Constructor Summary

ContainerUtil()

Method Summary

static void	configure(Container container, java.util.List<Configurator> configurators) Allow all the configurators to have a go at the container in turn
static void	configureContainerFully(Container container, javax.servlet.ServletConfig servletConfig) Run all the default configuration options on a Container
static boolean	configureFromAnnotations(Container container) Annotations must not break 1.3, so we use reflection to create an org.directwebremoting.annotations.AnnotationsConfigurator and the catch all sorts of random exceptions for the benefit of Websphere.
static void	configureFromDefaultDwrXml(Container container) Configure using the users dwr.xml that sits next in WEB-INF
static boolean	configureFromInitParams(Container container, javax.servlet.ServletConfig servletConfig) Add configurators from init params to the end of the list of configurators.
static void	configureFromSystemDwrXml(Container container) Configure using the system dwr.xml from within the JAR file.
static Container	createAndSetupDefaultContainer(javax.servlet.ServletConfig servletConfig) A combination of createDefaultContainer(ServletConfig) and setupDefaultContainer(DefaultContainer, ServletConfig).
static DefaultContainer	createDefaultContainer(javax.servlet.ServletConfig servletConfig) Deprecated. Use createAndSetupDefaultContainer(ServletConfig)
static void	createUrlMapping(DefaultContainer container, java.lang.String url, java.lang.String propertyName, java.lang.Class<?> handler) Creates entries in the Container so 2 lookups are possible.
static void	debugConfig(Container container) Create a bunch of debug information about a container
static java.util.List<Container>	getAllPublishedContainers(javax.servlet.ServletContext servletContext) Get a list of all known Containers for the given ServletContext
static ServerContext	getSingletonServerContext() If there is only once instance of DWR defined in a ServletContext then we can get at it using this method.
static void	prepareForWebContextFilter(javax.servlet.ServletContext context, javax.servlet.ServletConfig config, Container container, WebContextFactory.WebContextBuilder webContextBuilder, javax.servlet.http.HttpServlet servlet) Make some changes to the ServletContext so DwrWebContextFilter can find the Container etc.
static void	publishContainer(Container container, javax.servlet.ServletConfig servletConfig) If helps some situations if people can get at the container by looking in the servlet context, under some name.
static void	resolveContainerAbstraction(DefaultContainer container, javax.servlet.ServletConfig servletConfig) We need to decide which ContainerAbstraction should be the default for this Container, also we should prepare the default ServerLoadMonitor.
static void	setupDefaultContainer(DefaultContainer container, javax.servlet.ServletConfig servletConfig) Setup a DefaultContainer.
static void	setupDefaults(DefaultContainer container) Take a DefaultContainer and setup the default beans
static void	setupFromServletConfig(DefaultContainer container, javax.servlet.ServletConfig servletConfig) Take a DefaultContainer and setup the default beans
static void	shutdownServerLoadMonitorsInContainerList(java.util.List<Container> containers, java.lang.String title) Internal use only.

Methods inherited from class java.lang.Object

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

Field Detail

INIT_CONFIG

public static final java.lang.String INIT_CONFIG

Init parameter: Set a dwr.xml config file. This is only a prefix since we might have more than 1 config file.

See Also:

Constant Field Values

INIT_SKIP_DEFAULT

public static final java.lang.String INIT_SKIP_DEFAULT

Init parameter: Skip reading the default config file if none are specified.

See Also:

Constant Field Values

INIT_LOGLEVEL

public static final java.lang.String INIT_LOGLEVEL

Init parameter: If we are doing Servlet.log logging, to what level?

See Also:

Constant Field Values

INIT_CUSTOM_CONFIGURATOR

public static final java.lang.String INIT_CUSTOM_CONFIGURATOR

Init parameter: If you wish to use a custom configurator, place its class name here

See Also:

Constant Field Values

ATTRIBUTE_CONTAINER_LIST

public static final java.lang.String ATTRIBUTE_CONTAINER_LIST

The name under which we publish all Containers.

See Also:

Constant Field Values

DEFAULT_SERVERCONTEXT_NAME

public static final java.lang.String DEFAULT_SERVERCONTEXT_NAME

We store a single ServerContext in the contextMap under this name.

See Also:

Constant Field Values

Constructor Detail

ContainerUtil

public ContainerUtil()

Method Detail

createAndSetupDefaultContainer

public static Container createAndSetupDefaultContainer(javax.servlet.ServletConfig servletConfig)
                                                throws ContainerConfigurationException

A combination of createDefaultContainer(ServletConfig) and setupDefaultContainer(DefaultContainer, ServletConfig).

Parameters:

servletConfig - The source of init parameters

Returns:

A setup implementation of DefaultContainer

Throws:

ContainerConfigurationException - If the specified class could not be found or instantiated

createDefaultContainer

@Deprecated
public static DefaultContainer createDefaultContainer(javax.servlet.ServletConfig servletConfig)
                                               throws ContainerConfigurationException

Deprecated. Use createAndSetupDefaultContainer(ServletConfig)

Create a DefaultContainer, allowing users to upgrade to a child of DefaultContainer using an ServletConfig init parameter of org.directwebremoting.Container. Note that while the parameter name is the classname of Container, currently the only this can only be used to create children that inherit from DefaultContainer. This restriction may be relaxed in the future. Unlike setupDefaultContainer(DefaultContainer, ServletConfig), this method does not call any setup methods.

Parameters:

servletConfig - The source of init parameters

Returns:

An un'setup' implementation of DefaultContainer

Throws:

ContainerConfigurationException - If the specified class could not be found

See Also:

ServletConfig.getInitParameter(String)

setupDefaultContainer

public static void setupDefaultContainer(DefaultContainer container,
                                         javax.servlet.ServletConfig servletConfig)
                                  throws ContainerConfigurationException

Setup a DefaultContainer. Using createDefaultContainer(ServletConfig) followed by setupFromServletConfig(DefaultContainer, ServletConfig) before calling DefaultContainer.setupFinished().

Parameters:

container - The container to configure

servletConfig - The source of init parameters

Throws:

ContainerConfigurationException - If we can't use a bean

resolveContainerAbstraction

public static void resolveContainerAbstraction(DefaultContainer container,
                                               javax.servlet.ServletConfig servletConfig)
                                        throws ContainerConfigurationException

We need to decide which ContainerAbstraction should be the default for this Container, also we should prepare the default ServerLoadMonitor.

Parameters:

container - The container to configure

servletConfig - Information about the environment

Throws:

ContainerConfigurationException - If we can't use a bean

setupDefaults

public static void setupDefaults(DefaultContainer container)
                          throws ContainerConfigurationException

Take a DefaultContainer and setup the default beans

Parameters:

container - The container to configure

Throws:

ContainerConfigurationException - If we can't use a bean

createUrlMapping

public static void createUrlMapping(DefaultContainer container,
                                    java.lang.String url,
                                    java.lang.String propertyName,
                                    java.lang.Class<?> handler)
                             throws ContainerConfigurationException

Creates entries in the Container so 2 lookups are possible.

• You can find a Handler for a URL. Used by UrlProcessor
• You can inject (or lookup) the URL assigned to a Handler

Parameters:

container - The container to create the entries in

url - The URL of the new Handler

propertyName - The property name (for injection and lookup)

handler - The class of Handler

Throws:

ContainerConfigurationException - From DefaultContainer.addParameter(String, Object)

setupFromServletConfig

public static void setupFromServletConfig(DefaultContainer container,
                                          javax.servlet.ServletConfig servletConfig)
                                   throws ContainerConfigurationException

Take a DefaultContainer and setup the default beans

Parameters:

container - The container to configure

servletConfig - The servlet configuration (null to ignore)

Throws:

ContainerConfigurationException - If we can't use a bean

prepareForWebContextFilter

public static void prepareForWebContextFilter(javax.servlet.ServletContext context,
                                              javax.servlet.ServletConfig config,
                                              Container container,
                                              WebContextFactory.WebContextBuilder webContextBuilder,
                                              javax.servlet.http.HttpServlet servlet)

Make some changes to the ServletContext so DwrWebContextFilter can find the Container etc.

Parameters:

context - The servlet context

config - The servlet configuration

container - The container to save in the ServletContext

webContextBuilder - The WebContextBuilder to save

servlet - The Servlet to save

configureFromSystemDwrXml

public static void configureFromSystemDwrXml(Container container)
                                      throws java.io.IOException,
                                             javax.xml.parsers.ParserConfigurationException,
                                             org.xml.sax.SAXException

Configure using the system dwr.xml from within the JAR file.

Parameters:

container - The container to configure

Throws:

javax.xml.parsers.ParserConfigurationException - If the config file parse fails

java.io.IOException - If the config file read fails

org.xml.sax.SAXException - If the config file parse fails

configureFromDefaultDwrXml

public static void configureFromDefaultDwrXml(Container container)
                                       throws java.io.IOException,
                                              javax.xml.parsers.ParserConfigurationException,
                                              org.xml.sax.SAXException

Configure using the users dwr.xml that sits next in WEB-INF

Parameters:

container - The container to configure

Throws:

javax.xml.parsers.ParserConfigurationException - If the config file parse fails

java.io.IOException - If the config file read fails

org.xml.sax.SAXException - If the config file parse fails

configureFromInitParams

public static boolean configureFromInitParams(Container container,
                                              javax.servlet.ServletConfig servletConfig)
                                       throws java.io.IOException,
                                              javax.xml.parsers.ParserConfigurationException,
                                              org.xml.sax.SAXException

Add configurators from init params to the end of the list of configurators.

Parameters:

container - The container to configure

servletConfig - The source of init parameters

Returns:

true if any Configurators were read

Throws:

org.xml.sax.SAXException - If the config file parse fails

javax.xml.parsers.ParserConfigurationException - If the config file parse fails

java.io.IOException - If the config file read fails

configureFromAnnotations

public static boolean configureFromAnnotations(Container container)

Annotations must not break 1.3, so we use reflection to create an org.directwebremoting.annotations.AnnotationsConfigurator and the catch all sorts of random exceptions for the benefit of Websphere.

Parameters:

container - The container to configure

Returns:

true if the configuration worked.

configure

public static void configure(Container container,
                             java.util.List<Configurator> configurators)

Allow all the configurators to have a go at the container in turn

Parameters:

container - The container to configure

configurators - A list of configurators to run against the container

configureContainerFully

public static void configureContainerFully(Container container,
                                           javax.servlet.ServletConfig servletConfig)
                                    throws java.io.IOException,
                                           javax.xml.parsers.ParserConfigurationException,
                                           org.xml.sax.SAXException

Run all the default configuration options on a Container

Parameters:

container - The container to configure

servletConfig - The source of init parameters

Throws:

org.xml.sax.SAXException - If the config file parse fails

javax.xml.parsers.ParserConfigurationException - If the config file parse fails

java.io.IOException - If the config file read fails

publishContainer

public static void publishContainer(Container container,
                                    javax.servlet.ServletConfig servletConfig)

If helps some situations if people can get at the container by looking in the servlet context, under some name. The name is specified in an initParameter.

Parameters:

container - The container to publish

servletConfig - Source of initParams to dictate publishing and contexts to publish to

getSingletonServerContext

public static ServerContext getSingletonServerContext()

If there is only once instance of DWR defined in a ServletContext then we can get at it using this method.

Returns:

The one-and-only ServerContext or null if there are more than 1.

getAllPublishedContainers

public static java.util.List<Container> getAllPublishedContainers(javax.servlet.ServletContext servletContext)

Get a list of all known Containers for the given ServletContext

Parameters:

servletContext - The context in which Containers are stored.

Returns:

a list of published Containers.

shutdownServerLoadMonitorsInContainerList

public static void shutdownServerLoadMonitorsInContainerList(java.util.List<Container> containers,
                                                             java.lang.String title)

Internal use only.

If we detect that the server is being shutdown then we want to kill any reverse ajax threads.

Parameters:

containers - The list of containers to look for ServerLoadMonitors in

title - What causes this (for debug purposes)

debugConfig

public static void debugConfig(Container container)

Create a bunch of debug information about a container

Parameters:

container - The container to print debug information about