Package pl.morgwai.base.servlet.scopes

Class GuiceServletContextListener

java.lang.Object

pl.morgwai.base.servlet.scopes.GuiceServletContextListener

All Implemented Interfaces:

ServletContextListener, EventListener

Direct Known Subclasses:

PingingServletContextListener

public abstract class GuiceServletContextListener
extends Object
implements ServletContextListener

Creates and configures app wide Guice injector and a ServletModule. A single subclass of this class must be created and either annotated with @WebListener or enlisted in web.xml file in listener element.

Field Summary

Fields

Modifier and Type	Field	Description
protected GuiceServerEndpointConfigurator	endpointConfigurator	Stores the result of createEndpointConfigurator() to be used by addEndpoint(Class, String).
protected ServerContainer	endpointContainer	For use in configureServletsFiltersEndpoints().
protected static org.slf4j.Logger	log
protected ServletContext	servletContainer	For use in configureServletsFiltersEndpoints().
protected ServletModule	servletModule	For use in configureInjections().

Constructor Summary

Constructors

Constructor	Description
GuiceServletContextListener()

Method Summary

Modifier and Type	Method	Description
protected void	addEndpoint(Class<?> endpointClass, String path)	Adds an endpoint using endpointConfigurator (created by createEndpointConfigurator()).
protected void	addEndpoint(Class<?> endpointClass, String path, ServerEndpointConfig.Configurator configurator)	Adds an endpoint using custom configurator.
protected FilterRegistration.Dynamic	addFilter(String name, Class<? extends Filter> filterClass)	Adds a filter with async support and injects its dependencies.
protected FilterRegistration.Dynamic	addFilter(String name, Class<? extends Filter> filterClass, String... urlPatterns)	Adds a filter with async support and injects its dependencies, then adds a mapping at the end of the chain for urlPatterns and DispatcherType.REQUEST .
protected FilterRegistration.Dynamic	addFilter(String name, Class<? extends Filter> filterClass, EnumSet<DispatcherType> dispatcherTypes, String... urlPatterns)	Adds a filter with async support and injects its dependencies, then adds a mapping at the end of the chain for urlPatterns and dispatcherTypes.
protected ServletRegistration.Dynamic	addServlet(String name, Class<? extends HttpServlet> servletClass, String... urlPatterns)	Adds a servlet with async support and injects its dependencies.
protected abstract LinkedList<Module>	configureInjections()	Returns Modules that configure bindings for user-defined components.
protected abstract void	configureServletsFiltersEndpoints()	Programmatically adds servlets, filters and endpoints.
void	contextDestroyed(ServletContextEvent destructionEvent)	Shutdowns all executors from servletModule.
void	contextInitialized(ServletContextEvent initializationEvent)	Calls configureInjections(), creates the injector and calls configureServletsFiltersEndpoints().
protected GuiceServerEndpointConfigurator	createEndpointConfigurator()	Creates configurator to be used by addEndpoint(Class, String).
protected Injector	createInjector(LinkedList<Module> modules)	Creates injector.
protected int	getExecutorsShutdownTimeoutSeconds()	Returns the timeout for shutdown of executors obtained from servletModule.
static Injector	getInjector()	Returns app wide Guice Injector.
protected void	handleUncleanExecutorTerminations(List<ContextTrackingExecutor> executors)	Subclasses may override this method to examine the executors that failed to shutdown cleanly.

Methods inherited from class java.lang.Object

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

Field Detail

servletModule

protected final ServletModule servletModule

For use in configureInjections().

servletContainer

protected ServletContext servletContainer

For use in configureServletsFiltersEndpoints().

endpointContainer

protected ServerContainer endpointContainer

For use in configureServletsFiltersEndpoints().

endpointConfigurator

protected GuiceServerEndpointConfigurator endpointConfigurator

Stores the result of createEndpointConfigurator() to be used by addEndpoint(Class, String).

log

protected static final org.slf4j.Logger log

Constructor Detail

GuiceServletContextListener

public GuiceServletContextListener()

Method Detail

configureInjections

protected abstract LinkedList<Module> configureInjections()
                                                   throws ServletException

Returns Modules that configure bindings for user-defined components. The result will be passed when creating the app wide injector.

Implementations may use Scopes, ContextTrackers and helper methods from servletModule.

Throws:

ServletException

getInjector

public static Injector getInjector()

Returns app wide Guice Injector. Exposed as public static for non-programmatic servlets/filters to manually request dependency injection with Injector.injectMembers(Object) (usually in the init(config) method).

configureServletsFiltersEndpoints

protected abstract void configureServletsFiltersEndpoints()
                                                   throws ServletException

Programmatically adds servlets, filters and endpoints.

If all of these components are configured via annotations or web.xml file, then this method may be empty.

Convenience helper methods addServlet(String, Class, String...), addFilter(String, Class, String...), addEndpoint(Class, String) and addEndpoint(Class, String, Configurator) are provided for the most common cases.

This method is called after configureInjections() is called and the injector is created.

Throws:

ServletException

addServlet

protected ServletRegistration.Dynamic addServlet(String name,
                                                 Class<? extends HttpServlet> servletClass,
                                                 String... urlPatterns)
                                          throws ServletException

Adds a servlet with async support and injects its dependencies.

For use in configureServletsFiltersEndpoints().

Throws:

ServletException

addFilter

protected FilterRegistration.Dynamic addFilter(String name,
                                               Class<? extends Filter> filterClass)
                                        throws ServletException

Adds a filter with async support and injects its dependencies. Filter mappings should be added afterwards with FilterRegistration.addMappingForUrlPatterns(EnumSet, boolean, String...) or FilterRegistration.addMappingForServletNames(EnumSet, boolean, String...).

For use in configureServletsFiltersEndpoints().

Throws:

ServletException

addFilter

protected FilterRegistration.Dynamic addFilter(String name,
                                               Class<? extends Filter> filterClass,
                                               EnumSet<DispatcherType> dispatcherTypes,
                                               String... urlPatterns)
                                        throws ServletException

Adds a filter with async support and injects its dependencies, then adds a mapping at the end of the chain for urlPatterns and dispatcherTypes.

For use in configureServletsFiltersEndpoints().

Throws:

ServletException

addFilter

protected FilterRegistration.Dynamic addFilter(String name,
                                               Class<? extends Filter> filterClass,
                                               String... urlPatterns)
                                        throws ServletException

Adds a filter with async support and injects its dependencies, then adds a mapping at the end of the chain for urlPatterns and DispatcherType.REQUEST .

For use in configureServletsFiltersEndpoints().

Throws:

ServletException

createEndpointConfigurator

protected GuiceServerEndpointConfigurator createEndpointConfigurator()

Creates configurator to be used by addEndpoint(Class, String). By default GuiceServerEndpointConfigurator that injects endpoints' dependencies and sets up contexts.

This method is called once in contextInitialized(ServletContextEvent), the result is stored as endpointConfigurator and shared among all created endpoint instances.

Can be overridden by subclasses if another configurator needs to be used.

addEndpoint

protected void addEndpoint(Class<?> endpointClass,
                           String path)
                    throws ServletException

Adds an endpoint using endpointConfigurator (created by createEndpointConfigurator()). For use in configureServletsFiltersEndpoints().

Creates dynamic proxy class for endpointClass in advance.

Useful mostly for unannotated endpoints extending Endpoint.

Throws:

ServletException

addEndpoint

protected void addEndpoint(Class<?> endpointClass,
                           String path,
                           ServerEndpointConfig.Configurator configurator)
                    throws ServletException

Adds an endpoint using custom configurator.

Useful mostly for unannotated endpoints extending Endpoint.

Throws:

ServletException

contextInitialized

public final void contextInitialized(ServletContextEvent initializationEvent)

Calls configureInjections(), creates the injector and calls configureServletsFiltersEndpoints().

Also adds RequestContextFilter at the beginning of the chain.

Specified by:

contextInitialized in interface ServletContextListener

createInjector

protected Injector createInjector(LinkedList<Module> modules)

Creates injector. By default return Guice.createInjector(modules).

contextDestroyed

public void contextDestroyed(ServletContextEvent destructionEvent)

Shutdowns all executors from servletModule.

Specified by:

contextDestroyed in interface ServletContextListener

getExecutorsShutdownTimeoutSeconds

protected int getExecutorsShutdownTimeoutSeconds()

Returns the timeout for shutdown of executors obtained from servletModule. By default 5 seconds.

handleUncleanExecutorTerminations

protected void handleUncleanExecutorTerminations(List<ContextTrackingExecutor> executors)

Subclasses may override this method to examine the executors that failed to shutdown cleanly. By default does nothing.