org.apache.tapestry
Class ApplicationServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.apache.tapestry.ApplicationServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class ApplicationServlet
extends HttpServlet

Links a servlet container with a Tapestry application. The servlet init parameter org.apache.tapestry.application-specification should be set to the complete resource path (within the classpath) to the application specification, i.e., /com/foo/bar/MyApp.application. As of release 4.0, this servlet will also create a HiveMind Registry and manage it.

Author:

Howard Lewis Ship

See Also:

ApplicationInitializer, ServletRequestServicer, Serialized Form

Constructor Summary

ApplicationServlet()

Method Summary

protected void	addModuleIfExists(org.apache.hivemind.impl.RegistryBuilder builder, ServletContext context, String path) Looks for a file in the servlet context; if it exists, it is expected to be a HiveMind module descriptor, and is added to the builder.
protected org.apache.hivemind.ErrorHandler	constructErrorHandler(ServletConfig config) Invoked by constructRegistry(ServletConfig) to create and return an ErrorHandler instance to be used when constructing the Registry (and then to handle any runtime exceptions).
protected org.apache.hivemind.Registry	constructRegistry(ServletConfig config) Invoked from init(ServletConfig)to construct the Registry to be used by the application.
protected org.apache.hivemind.ClassResolver	createClassResolver() Invoked from init(ServletConfig)to create a resource resolver for the servlet (which will utlimately be shared and used through the application).
void	destroy() Shuts down the registry (if it exists).
void	doGet(HttpServletRequest request, HttpServletResponse response) Invokes doService(HttpServletRequest, HttpServletResponse).
void	doPost(HttpServletRequest request, HttpServletResponse response) Invokes doService(HttpServletRequest, HttpServletResponse).
protected void	doService(HttpServletRequest request, HttpServletResponse response) Handles the GET and POST requests.
void	init(ServletConfig config) Reads the application specification when the servlet is first initialized.
protected void	initializeApplication() Invoked from init(ServletConfig), after the registry has been constructed, to bootstrap the application via the tapestry.MasterApplicationInitializer service.
protected void	show(Exception ex)

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Constructor Detail

ApplicationServlet

public ApplicationServlet()

Method Detail

doGet

public void doGet(HttpServletRequest request,
                  HttpServletResponse response)
           throws IOException,
                  ServletException

Invokes doService(HttpServletRequest, HttpServletResponse).

Overrides:

doGet in class HttpServlet

Throws:

IOException

ServletException

Since:

1.0.6

doService

protected void doService(HttpServletRequest request,
                         HttpServletResponse response)
                  throws IOException,
                         ServletException

Handles the GET and POST requests. Performs the following:

• Invokes Registry.setupThread()
• Invokes ServletRequestServicer.service(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse).

Throws:

IOException

ServletException

show

protected void show(Exception ex)

doPost

public void doPost(HttpServletRequest request,
                   HttpServletResponse response)
            throws IOException,
                   ServletException

Invokes doService(HttpServletRequest, HttpServletResponse).

Overrides:

doPost in class HttpServlet

Throws:

IOException

ServletException

init

public void init(ServletConfig config)
          throws ServletException

Reads the application specification when the servlet is first initialized. All engine instanceswill have access to the specification via the servlet.

Specified by:

init in interface Servlet

Overrides:

init in class GenericServlet

Throws:

ServletException

See Also:

constructRegistry(ServletConfig), createClassResolver()

createClassResolver

protected org.apache.hivemind.ClassResolver createClassResolver()

Invoked from init(ServletConfig)to create a resource resolver for the servlet (which will utlimately be shared and used through the application).

This implementation constructs a DefaultClassResolver, subclasses may provide a different implementation.

Since:

2.3

See Also:

DefaultClassResolver

constructRegistry

protected org.apache.hivemind.Registry constructRegistry(ServletConfig config)

Invoked from init(ServletConfig)to construct the Registry to be used by the application.

This looks in the standard places (on the classpath), but also in the WEB-INF/name and WEB-INF folders (where name is the name of the servlet).

Since:

4.0

constructErrorHandler

protected org.apache.hivemind.ErrorHandler constructErrorHandler(ServletConfig config)

Invoked by constructRegistry(ServletConfig) to create and return an ErrorHandler instance to be used when constructing the Registry (and then to handle any runtime exceptions). This implementation returns a new instance of StrictErrorHandler.

Since:

4.0

addModuleIfExists

protected void addModuleIfExists(org.apache.hivemind.impl.RegistryBuilder builder,
                                 ServletContext context,
                                 String path)

Looks for a file in the servlet context; if it exists, it is expected to be a HiveMind module descriptor, and is added to the builder.

Since:

4.0

initializeApplication

protected void initializeApplication()

Invoked from init(ServletConfig), after the registry has been constructed, to bootstrap the application via the tapestry.MasterApplicationInitializer service.

Since:

4.0

destroy

public void destroy()

Shuts down the registry (if it exists).

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

Since:

4.0