org.apache.cocoon.servlet
Class CocoonServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.apache.cocoon.servlet.CocoonServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

public class CocoonServlet
extends HttpServlet

This is the entry point for Cocoon execution as an HTTP Servlet.

Version:

$Id: CocoonServlet.html 1304258 2012-03-23 10:09:27Z ilgrosso $

Author:

Pierpaolo Fumagalli (Apache Software Foundation), Stefano Mazzocchi, Nicola Ken Barozzi, Berin Loritsch, Carsten Ziegeler, Leo Sutic

See Also:

Serialized Form

Field Summary

protected static boolean	ALLOW_RELOAD Default value for allowReload parameter (false)
protected boolean	allowReload Allow reloading of cocoon by specifying the cocoon-reload=true parameter with a request
protected DefaultContext	appContext Avalon application context
protected ClassLoader	classLoader The classloader that will be set as the context classloader if init-classloader is true
protected Cocoon	cocoon The Cocoon instance
static String	CONTEXT_SERVLET_CONFIG Application Context Key for the servlet configuration
protected long	creationTime The time the cocoon instance was created
protected Exception	exception Holds exception happened during initialization (if any)
protected String	forceLoadParameter
protected String	forceSystemProperty
protected boolean	hiddenShowTime If true, processing time will be added as an HTML comment
protected boolean	initClassLoader
protected static String	PROCESSED_BY
protected RequestFactory	requestFactory The RequestFactory is responsible for wrapping multipart-encoded forms and for handing the file payload of incoming requests
protected ServletContext	servletContext
protected String	servletContextPath This is the path to the servlet context (or the result of calling getRealPath('/') on the ServletContext.
protected String	servletContextURL This is the url to the servlet context directory
protected boolean	showTime Allow adding processing time to the response

Constructor Summary

CocoonServlet()

Method Summary

protected void	addClassLoaderDirectory(String dir) Adds a directory to the classloader.
protected void	addClassLoaderURL(URL URL) Adds an URL to the classloader.
protected void	createCocoon() Creates the Cocoon object and handles exception handling.
void	destroy() Dispose Cocoon when servlet is destroyed
protected void	disposeCocoon() Destroy Cocoon
protected String	getClassPath() This builds the important ClassPath used by this Servlet.
protected Environment	getEnvironment(String uri, HttpServletRequest req, HttpServletResponse res) Create the environment for the request
protected String	getExtraClassPath() Retreives the "extra-classpath" attribute, that needs to be added to the class path.
String	getInitParameter(String name) Get an initialisation parameter.
protected String	getInitParameter(String name, String defaultValue) Convenience method to access servlet parameters
protected boolean	getInitParameterAsBoolean(String name, boolean defaultValue) Convenience method to access boolean servlet parameters
protected int	getInitParameterAsInteger(String name, int defaultValue)
protected Logger	getLogger()
protected LoggerManager	getLoggerManager()
protected ComponentManager	getParentComponentManager() Instatiates the parent component manager, as specified in the parent-component-manager init parameter.
void	init(ServletConfig conf) Initialize this CocoonServlet instance.
protected void	initLogger() Set up the log level and path.
protected void	manageException(HttpServletRequest req, HttpServletResponse res, Environment env, String uri, int errorStatus, String title, String message, String description, Exception e)
void	service(HttpServletRequest req, HttpServletResponse res) Process the specified HttpServletRequest producing output on the specified HttpServletResponse.
protected void	updateEnvironment() Method to update the environment before Cocoon instances are created.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

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

Field Detail

CONTEXT_SERVLET_CONFIG

public static final String CONTEXT_SERVLET_CONFIG

Application Context Key for the servlet configuration

Since:

2.1.3

See Also:

Constant Field Values

PROCESSED_BY

protected static final String PROCESSED_BY

creationTime

protected long creationTime

The time the cocoon instance was created

cocoon

protected Cocoon cocoon

The Cocoon instance

exception

protected Exception exception

Holds exception happened during initialization (if any)

appContext

protected DefaultContext appContext

Avalon application context

ALLOW_RELOAD

protected static final boolean ALLOW_RELOAD

Default value for allowReload parameter (false)

See Also:

Constant Field Values

allowReload

protected boolean allowReload

Allow reloading of cocoon by specifying the cocoon-reload=true parameter with a request

showTime

protected boolean showTime

Allow adding processing time to the response

hiddenShowTime

protected boolean hiddenShowTime

If true, processing time will be added as an HTML comment

servletContext

protected ServletContext servletContext

classLoader

protected ClassLoader classLoader

The classloader that will be set as the context classloader if init-classloader is true

initClassLoader

protected boolean initClassLoader

forceLoadParameter

protected String forceLoadParameter

forceSystemProperty

protected String forceSystemProperty

servletContextPath

protected String servletContextPath

This is the path to the servlet context (or the result of calling getRealPath('/') on the ServletContext. Note, that this can be null.

servletContextURL

protected String servletContextURL

This is the url to the servlet context directory

requestFactory

protected RequestFactory requestFactory

The RequestFactory is responsible for wrapping multipart-encoded forms and for handing the file payload of incoming requests

Constructor Detail

CocoonServlet

public CocoonServlet()

Method Detail

init

public void init(ServletConfig conf)
          throws ServletException

Initialize this CocoonServlet instance. You will notice that I have broken the init into sub methods to make it easier to maintain (BL). The context is passed to a couple of the subroutines. This is also because it is better to explicitly pass variables than implicitely. It is both more maintainable, and more elegant.

Specified by:

init in interface Servlet

Overrides:

init in class GenericServlet

Parameters:

conf - The ServletConfig object from the servlet engine.

Throws:

ServletException

destroy

public void destroy()

Dispose Cocoon when servlet is destroyed

Specified by:

destroy in interface Servlet

Overrides:

destroy in class GenericServlet

addClassLoaderURL

protected void addClassLoaderURL(URL URL)

Adds an URL to the classloader. Does nothing here, but is overriden in ParanoidCocoonServlet.

addClassLoaderDirectory

protected void addClassLoaderDirectory(String dir)

Adds a directory to the classloader. Does nothing here, but is overriden in ParanoidCocoonServlet.

getClassPath

protected String getClassPath()
                       throws ServletException

This builds the important ClassPath used by this Servlet. It does so in a Servlet Engine neutral way. It uses the ServletContext's getRealPath method to get the Servlet 2.2 identified classes and lib directories. It iterates in alphabetical order through every file in the lib directory and adds it to the classpath. Also, we add the files to the ClassLoader for the Cocoon system. In order to protect ourselves from skitzofrantic classloaders, we need to work with a known one. We need to get this to work properly when Cocoon is in a war.

Throws:

ServletException

getExtraClassPath

protected String getExtraClassPath()
                            throws ServletException

Retreives the "extra-classpath" attribute, that needs to be added to the class path.

Throws:

ServletException

initLogger

protected void initLogger()

Set up the log level and path. The default log level is Priority.ERROR, although it can be overwritten by the parameter "log-level". The log system goes to both a file and the Servlet container's log system. Only messages that are Priority.ERROR and above go to the servlet context. The log messages can be as restrictive (Priority.FATAL_ERROR and above) or as liberal (Priority.DEBUG and above) as you want that get routed to the file.

service

public void service(HttpServletRequest req,
                    HttpServletResponse res)
             throws ServletException,
                    IOException

Process the specified HttpServletRequest producing output on the specified HttpServletResponse.

Overrides:

service in class HttpServlet

Throws:

ServletException

IOException

manageException

protected void manageException(HttpServletRequest req,
                               HttpServletResponse res,
                               Environment env,
                               String uri,
                               int errorStatus,
                               String title,
                               String message,
                               String description,
                               Exception e)
                        throws IOException

Throws:

IOException

getEnvironment

protected Environment getEnvironment(String uri,
                                     HttpServletRequest req,
                                     HttpServletResponse res)
                              throws Exception

Create the environment for the request

Throws:

Exception

getParentComponentManager

protected ComponentManager getParentComponentManager()

Instatiates the parent component manager, as specified in the parent-component-manager init parameter. If none is specified, the method returns null.

Returns:

the parent component manager, or null.

createCocoon

protected void createCocoon()
                     throws ServletException

Creates the Cocoon object and handles exception handling.

Throws:

ServletException

updateEnvironment

protected void updateEnvironment()
                          throws ServletException

Method to update the environment before Cocoon instances are created. This is also useful if you wish to customize any of the 'protected' variables from this class before a Cocoon instance is built in a derivative of this class (eg. Cocoon Context).

Throws:

ServletException

disposeCocoon

protected final void disposeCocoon()

Destroy Cocoon

getInitParameter

public String getInitParameter(String name)

Get an initialisation parameter. The value is trimmed, and null is returned if the trimmed value is empty.

Specified by:

getInitParameter in interface ServletConfig

Overrides:

getInitParameter in class GenericServlet

getInitParameter

protected String getInitParameter(String name,
                                  String defaultValue)

Convenience method to access servlet parameters

getInitParameterAsBoolean

protected boolean getInitParameterAsBoolean(String name,
                                            boolean defaultValue)

Convenience method to access boolean servlet parameters

getInitParameterAsInteger

protected int getInitParameterAsInteger(String name,
                                        int defaultValue)

getLogger

protected Logger getLogger()

getLoggerManager

protected LoggerManager getLoggerManager()