nextapp.echo.webcontainer
Class WebContainerServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          nextapp.echo.webcontainer.WebContainerServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public abstract class WebContainerServlet
extends javax.servlet.http.HttpServlet

Web container HttpServlet implementation. An Echo application should provide an derivative of this class which is registered in the web application deployment descriptor.

See Also:

Serialized Form

Nested Class Summary

static interface

WebContainerServlet.MultipartRequestWrapper An interface implemented by a supporting object that will handle multipart/form-data encoded HTTP requests.

Field Summary

static boolean	DEBUG_PRINT_MESSAGES_TO_CONSOLE Flag indicating whether client/server messages should be dumped to console.
static boolean	DISABLE_CACHING A flag indicating whether caching should be disabled for all services.
static boolean	ENABLE_CLIENT_DEBUG_CONSOLE Flag indicating whether client-side debug console should be enabled.
static int	INSTANCE_MODE_SINGLE Constant for getInstanceMode() indicating that one instance (UserInstance of the application should exist per session.
static int	INSTANCE_MODE_WINDOW Constant for getInstanceMode() indicating that one instance (UserInstance of the application should exist per session per client browser window.
static java.lang.String	SERVICE_ID_BLANK_DOCUMENT Service identifier of the blank document service.
static java.lang.String	SERVICE_ID_DEFAULT Service identifier of the 'default' service.
static java.lang.String	SERVICE_ID_NEW_INSTANCE Service identifier of the 'new instance' service.
static java.lang.String	SERVICE_ID_PARAMETER Request parameter identifying requested Service.
static java.lang.String	SERVICE_ID_SESSION_EXPIRED Service identifier of the 'session expired' service.
static java.lang.String	USER_INSTANCE_ID_PARAMETER Request parameter identifying requested UserInstance.

Constructor Summary

WebContainerServlet()
Default constructor.

Method Summary

protected void	addInitScript(Service service) Adds a JavaScript service to be loaded at initialization.
protected void	addInitStyleSheet(Service service) Adds a CSS style sheet to be loaded at initialization.
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Handles a GET request.
void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Handles a POST request.
static Connection	getActiveConnection() Returns a reference to the Connection that is relevant to the current thread, or null if no connection is relevant.
java.util.Iterator	getInitScripts() Returns an iterator over initialization script services.
java.util.Iterator	getInitStyleSheets() Returns an iterator over initialization script services.
int	getInstanceMode() Returns the instance operating mode of the application, determining how the application will perform if it is visited by multiple browser windows.
static WebContainerServlet.MultipartRequestWrapper	getMultipartRequestWrapper() Returns the multipart/form-data encoded HTTP request handler.
static ResourceRegistry	getResourceRegistry() Retrieves the global ResourceRegistry.
static ServiceRegistry	getServiceRegistry() Retrieves the global ServiceRegistry.
abstract nextapp.echo.app.ApplicationInstance	newApplicationInstance() Creates a new ApplicationInstance for visitor to an application.
protected void	process(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Processes an HTTP request and generates a response.
static void	setMultipartRequestWrapper(WebContainerServlet.MultipartRequestWrapper multipartRequestWrapper) Sets the multipart/form-data encoded HTTP request handler.

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Field Detail

DEBUG_PRINT_MESSAGES_TO_CONSOLE

public static final boolean DEBUG_PRINT_MESSAGES_TO_CONSOLE

Flag indicating whether client/server messages should be dumped to console.

DISABLE_CACHING

public static final boolean DISABLE_CACHING

A flag indicating whether caching should be disabled for all services. This flag is for testing purposes only, and should be disabled for production use.

See Also:

Constant Field Values

ENABLE_CLIENT_DEBUG_CONSOLE

public static final boolean ENABLE_CLIENT_DEBUG_CONSOLE

Flag indicating whether client-side debug console should be enabled.

See Also:

Constant Field Values

INSTANCE_MODE_SINGLE

public static final int INSTANCE_MODE_SINGLE

Constant for getInstanceMode() indicating that one instance (UserInstance of the application should exist per session. If the user visits the application in a different browser window, the state of the singleton instance will be displayed. The user will experience "window not synchronized" errors if the user attempts to operate the same application from multiple windows.

See Also:

Constant Field Values

INSTANCE_MODE_WINDOW

public static final int INSTANCE_MODE_WINDOW

Constant for getInstanceMode() indicating that one instance (UserInstance of the application should exist per session per client browser window. If the user visits the application in a different browser window, a new instance will be created.

See Also:

Constant Field Values

SERVICE_ID_PARAMETER

public static final java.lang.String SERVICE_ID_PARAMETER

Request parameter identifying requested Service.

See Also:

Constant Field Values

USER_INSTANCE_ID_PARAMETER

public static final java.lang.String USER_INSTANCE_ID_PARAMETER

Request parameter identifying requested UserInstance.

See Also:

Constant Field Values

SERVICE_ID_DEFAULT

public static final java.lang.String SERVICE_ID_DEFAULT

Service identifier of the 'default' service. The 'default' service is rendered when a client makes a request without a service identifier and a session DOES exist.

See Also:

Constant Field Values

SERVICE_ID_BLANK_DOCUMENT

public static final java.lang.String SERVICE_ID_BLANK_DOCUMENT

Service identifier of the blank document service.

See Also:

Constant Field Values

SERVICE_ID_NEW_INSTANCE

public static final java.lang.String SERVICE_ID_NEW_INSTANCE

Service identifier of the 'new instance' service. The 'new instance' service is rendered when a client makes a request without a service identifier and a session DOES NOT exist.

See Also:

Constant Field Values

SERVICE_ID_SESSION_EXPIRED

public static final java.lang.String SERVICE_ID_SESSION_EXPIRED

Service identifier of the 'session expired' service. The 'session expired' service is rendered when a client makes a request that has an identifier and is intended for an active session, but no session exists.

See Also:

Constant Field Values

Constructor Detail

WebContainerServlet

public WebContainerServlet()

Default constructor.

Method Detail

getActiveConnection

public static final Connection getActiveConnection()

Returns a reference to the Connection that is relevant to the current thread, or null if no connection is relevant.

Returns:

the relevant Connection

getMultipartRequestWrapper

public static WebContainerServlet.MultipartRequestWrapper getMultipartRequestWrapper()

Returns the multipart/form-data encoded HTTP request handler.

Returns:

The multipart/form-data encoded HTTP request handler.

See Also:

setMultipartRequestWrapper(nextapp.echo.webcontainer.WebContainerServlet.MultipartRequestWrapper)

getResourceRegistry

public static ResourceRegistry getResourceRegistry()

Retrieves the global ResourceRegistry.

Returns:

the global ResourceRegistry

getServiceRegistry

public static ServiceRegistry getServiceRegistry()

Retrieves the global ServiceRegistry.

Returns:

The global ServiceRegistry.

setMultipartRequestWrapper

public static final void setMultipartRequestWrapper(WebContainerServlet.MultipartRequestWrapper multipartRequestWrapper)

Sets the multipart/form-data encoded HTTP request handler. The multipart request wrapper can only be set one time. It should be set in a static block of your Echo application. This method will disregard additional attempts to set the wrapper if the provided wrapper's class is identical to the existing one. If the wrapper is already set and the new wrapper object's class is different or the wrapper is null, an exception is thrown.

Parameters:

multipartRequestWrapper - The handler for multipart/form-data encoded HTTP requests.

Throws:

java.lang.IllegalStateException - if the application attempts to change a previously set multipart request handler.

addInitScript

protected void addInitScript(Service service)

Adds a JavaScript service to be loaded at initialization.

Parameters:

service - the service which will provide JavaScript content.

addInitStyleSheet

protected void addInitStyleSheet(Service service)

Adds a CSS style sheet to be loaded at initialization.

Parameters:

service - the service which will provide the CSS content.

doGet

public final void doGet(javax.servlet.http.HttpServletRequest request,
                        javax.servlet.http.HttpServletResponse response)
                 throws java.io.IOException,
                        javax.servlet.ServletException

Handles a GET request.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

process(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

doPost

public final void doPost(javax.servlet.http.HttpServletRequest request,
                         javax.servlet.http.HttpServletResponse response)
                  throws java.io.IOException,
                         javax.servlet.ServletException

Handles a POST request.

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

process(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)

getInitScripts

public java.util.Iterator getInitScripts()

Returns an iterator over initialization script services.

Returns:

the iterator

getInitStyleSheets

public java.util.Iterator getInitStyleSheets()

Returns an iterator over initialization script services.

Returns:

the iterator

getInstanceMode

public int getInstanceMode()

Returns the instance operating mode of the application, determining how the application will perform if it is visited by multiple browser windows.

Returns:

the operating mode, one of the following values:

• INSTANCE_MODE_SINGLE (the default) to allow only a single instance of the application
• INSTANCE_MODE_WINDOW to allow multiple instances of the application per session, with new instances created for new browser windows

newApplicationInstance

public abstract nextapp.echo.app.ApplicationInstance newApplicationInstance()

Creates a new ApplicationInstance for visitor to an application.

Returns:

a new ApplicationInstance

process

protected void process(javax.servlet.http.HttpServletRequest request,
                       javax.servlet.http.HttpServletResponse response)
                throws java.io.IOException,
                       javax.servlet.ServletException

Processes an HTTP request and generates a response.

Parameters:

request - the incoming HttpServletRequest

response - the outgoing HttpServletResponse

Throws:

java.io.IOException

javax.servlet.ServletException