com.creamtec.ajaxswing
Class ServletHelper

java.lang.Object
  com.creamtec.ajaxswing.ServletHelper

All Implemented Interfaces:

AjaxSwingServlet

public final class ServletHelper
extends java.lang.Object
implements AjaxSwingServlet

Provides implementation for most of the logic of processing an incoming HTTP servlet request and forwarding it to a client agent.

Nested Class Summary

class	ServletHelper.InProcessAppDesc Declare this class to resolve classpath to the application classes.
static class	ServletHelper.InProcessClientAgent Declare this class to resolve classpath to the application classes.

Field Summary

static java.lang.String	APP_NAME
FileUploadHandler	fileUploadHandler
static java.lang.String	PROPS_FILE_NAME

Method Summary

static long	copyInputToOutput(java.io.InputStream input, java.io.OutputStream output) Copy bytes from an InputStream to an OutputStream.
ClientAgent	createClientAgent(java.lang.String appName) Creates a new client agent.
java.lang.String	decodeValue(java.lang.String value) Decode value from the source encoding into internal UTF8 encoding
AgentInitData	getAgentInitData(AppDesc appDesc, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
AppDesc	getAppDesc(javax.servlet.http.HttpServletRequest request, java.lang.String appName) Returns the application descriptor for a given request
ClientAgentRemote	getClientAgent(AppDesc appDesc, javax.servlet.http.HttpServletRequest request, HttpRequestData requestData, javax.servlet.http.HttpServletResponse response) Returns a client agent that should process the given request.
static int	getClientId(ClientAgentRemote agent) We have to use Object's implementation of hashCode() because RemoteObject always return the same value for all out-of-process agents
java.lang.String	getDocsRealPath(AppDesc appDesc, javax.servlet.http.HttpServletRequest request) Real path is disk path such as C:\Java\AjaxSwing and it's needed for SnapshotRenderer temp directory
static ServletHelper	getInstance(javax.servlet.ServletContext servletContext) Returns the instance of the servlet helper
static java.lang.String	getListenerName(java.lang.String appName) Helper method to return the listener name for a given application name
java.lang.String	getParameterValue(javax.servlet.http.HttpServletRequest request, java.lang.String name) Returns the value of the given request parameter
java.lang.String[]	getParameterValues(javax.servlet.http.HttpServletRequest request, java.lang.String name) Returns all values of a HTTP request parameter.
RouterRequestFilter	getRequestFilter() Returns the request filter instance
static java.lang.String	getServerURL(javax.servlet.http.HttpServletRequest request) Obtains the web server URL based on the scheme, port and web app context.
java.lang.Object	getSessionAttribute(javax.servlet.http.HttpSession session, java.lang.String name) Version-safe way of getting a value from a session
java.lang.String	getSubmitURL(AppDesc appDesc, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Obtains the submit URL based on the application configuration or the request URL
void	parseAppNameAndAction(javax.servlet.http.HttpServletRequest request, HttpRequestData data) Obtain application name and the requested action from HTTP parameters and query string
void	processHttpRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Extracts parameters from HttpServletRequest, finds (creates) a client agent and delegates to it for processing and HTML generation.
void	processRequestData(AppDesc appDesc, javax.servlet.http.HttpServletRequest request, HttpRequestData requestData) Extracts and processes the request data
boolean	processRouterMode(javax.servlet.http.HttpServletRequest request, HttpRequestData data) Sets the servlet parameters such as the application name and action based on the deployment method
void	removeSessionAttribute(javax.servlet.http.HttpSession session, java.lang.String name) Version-safe way of removing a value from a session
void	setDataFromPath(HttpRequestData data, java.lang.String path) Extracts the servlet parameters such as the application name and action from the given string
void	setSessionAttribute(javax.servlet.http.HttpSession session, java.lang.String name, java.lang.Object value) Version-safe way of storing a value in a session
void	shutdown() Shuts down agents and all running external JVMs
static void	shutdownAgent(AppDesc appDesc, java.lang.Integer sessionId, ClientAgentRemote agent) Shuts down the client agent
void	shutdownAllAgents()

Methods inherited from class java.lang.Object

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

Field Detail

fileUploadHandler

public FileUploadHandler fileUploadHandler

APP_NAME

public static final java.lang.String APP_NAME

See Also:

Constant Field Values

PROPS_FILE_NAME

public static final java.lang.String PROPS_FILE_NAME

See Also:

Constant Field Values

Method Detail

getParameterValue

public java.lang.String getParameterValue(javax.servlet.http.HttpServletRequest request,
                                          java.lang.String name)
                                   throws java.lang.Exception

Returns the value of the given request parameter

Parameters:

request - HttpServletRequest

name - parameter name

Returns:

parameter value

Throws:

java.lang.Exception

getParameterValues

public java.lang.String[] getParameterValues(javax.servlet.http.HttpServletRequest request,
                                             java.lang.String name)
                                      throws java.lang.Exception

Returns all values of a HTTP request parameter. For instance, lists with multiple selection return all selected items.

Parameters:

request - HttpServletRequest

name - parameter name

Returns:

array of values

Throws:

java.lang.Exception

decodeValue

public java.lang.String decodeValue(java.lang.String value)
                             throws java.lang.Exception

Decode value from the source encoding into internal UTF8 encoding

Parameters:

value - String

Returns:

String

Throws:

java.lang.Exception

shutdown

public void shutdown()

Shuts down agents and all running external JVMs

shutdownAllAgents

public void shutdownAllAgents()

processHttpRequest

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

Extracts parameters from HttpServletRequest, finds (creates) a client agent and delegates to it for processing and HTML generation.

Parameters:

request - HttpServletRequest

response - HttpServletResponse

Throws:

java.io.IOException

copyInputToOutput

public static long copyInputToOutput(java.io.InputStream input,
                                     java.io.OutputStream output)
                              throws java.io.IOException

Copy bytes from an InputStream to an OutputStream.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Large streams (over 2GB) will return a bytes copied value of -1 after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use the copyLarge(InputStream, OutputStream) method.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

Returns:

the number of bytes copied

Throws:

java.lang.NullPointerException - if the input or output is null

java.io.IOException - if an I/O error occurs

java.lang.ArithmeticException - if the byte count is too large

getSubmitURL

public java.lang.String getSubmitURL(AppDesc appDesc,
                                     javax.servlet.http.HttpServletRequest request,
                                     javax.servlet.http.HttpServletResponse response)

Obtains the submit URL based on the application configuration or the request URL

Parameters:

appDesc - application descriptor

request - HttpServletRequest

Returns:

URL used to submit pages to AjaxSwingRouter servlet

Throws:

java.lang.Exception

getDocsRealPath

public java.lang.String getDocsRealPath(AppDesc appDesc,
                                        javax.servlet.http.HttpServletRequest request)
                                 throws java.lang.Exception

Real path is disk path such as C:\Java\AjaxSwing and it's needed for SnapshotRenderer temp directory

Throws:

java.lang.Exception

getServerURL

public static java.lang.String getServerURL(javax.servlet.http.HttpServletRequest request)

Obtains the web server URL based on the scheme, port and web app context.

Parameters:

appDesc - AppDesc

request - HttpServletRequest

Returns:

String

Throws:

java.lang.Exception

processRequestData

public void processRequestData(AppDesc appDesc,
                               javax.servlet.http.HttpServletRequest request,
                               HttpRequestData requestData)
                        throws java.lang.Exception

Extracts and processes the request data

Parameters:

appDesc - application descriptor

request - HttpServletRequest

requestData - HttpRequestData

Throws:

java.lang.Exception

getClientAgent

public ClientAgentRemote getClientAgent(AppDesc appDesc,
                                        javax.servlet.http.HttpServletRequest request,
                                        HttpRequestData requestData,
                                        javax.servlet.http.HttpServletResponse response)
                                 throws java.lang.Exception

Returns a client agent that should process the given request. The agent is first looked up based on the session information. If an existing agent is not found, a new one is created and initialized.

Parameters:

appDesc - application descriptor

request - HttpServletRequest

requestData - HttpRequestData

response - HttpServletResponse

Returns:

ClientAgentRemote

Throws:

java.lang.Exception

createClientAgent

public ClientAgent createClientAgent(java.lang.String appName)
                              throws java.lang.Exception

Creates a new client agent.

Specified by:

createClientAgent in interface AjaxSwingServlet

Parameters:

appName - application name

Returns:

ClientAgent

Throws:

java.lang.Exception

shutdownAgent

public static void shutdownAgent(AppDesc appDesc,
                                 java.lang.Integer sessionId,
                                 ClientAgentRemote agent)

Shuts down the client agent

Parameters:

appDesc - application descriptor

sessionId - AjaxSwing internal session identification

agent - ClientAgentRemote

getAgentInitData

public AgentInitData getAgentInitData(AppDesc appDesc,
                                      javax.servlet.http.HttpServletRequest request,
                                      javax.servlet.http.HttpServletResponse response)
                               throws java.lang.Exception

Throws:

java.lang.Exception

getClientId

public static int getClientId(ClientAgentRemote agent)

We have to use Object's implementation of hashCode() because RemoteObject always return the same value for all out-of-process agents

Parameters:

agent -

Returns:

unique client agent id

getAppDesc

public AppDesc getAppDesc(javax.servlet.http.HttpServletRequest request,
                          java.lang.String appName)
                   throws java.lang.Exception

Returns the application descriptor for a given request

Parameters:

request - HttpServletRequest

data - HttpRequestData

Returns:

AppDesc

Throws:

java.lang.Exception

parseAppNameAndAction

public void parseAppNameAndAction(javax.servlet.http.HttpServletRequest request,
                                  HttpRequestData data)
                           throws java.lang.Exception

Obtain application name and the requested action from HTTP parameters and query string

Throws:

java.lang.Exception

processRouterMode

public boolean processRouterMode(javax.servlet.http.HttpServletRequest request,
                                 HttpRequestData data)
                          throws java.lang.Exception

Sets the servlet parameters such as the application name and action based on the deployment method

Parameters:

request - HttpServletRequest

data - HttpRequestData

Returns:

true if the method was able to determine the deployment method

Throws:

java.lang.Exception

getSessionAttribute

public java.lang.Object getSessionAttribute(javax.servlet.http.HttpSession session,
                                            java.lang.String name)
                                     throws java.lang.Exception

Version-safe way of getting a value from a session

Parameters:

session - HttpSession

name - attribute name

Returns:

value

Throws:

java.lang.Exception

setSessionAttribute

public void setSessionAttribute(javax.servlet.http.HttpSession session,
                                java.lang.String name,
                                java.lang.Object value)

Version-safe way of storing a value in a session

Parameters:

session - HttpSession

name - attribute name

value - attribute value

Throws:

java.lang.Exception

removeSessionAttribute

public void removeSessionAttribute(javax.servlet.http.HttpSession session,
                                   java.lang.String name)
                            throws java.lang.Exception

Version-safe way of removing a value from a session

Parameters:

session - HttpSession

name - attribute name

Throws:

java.lang.Exception

setDataFromPath

public void setDataFromPath(HttpRequestData data,
                            java.lang.String path)
                     throws java.lang.Exception

Extracts the servlet parameters such as the application name and action from the given string

Parameters:

data - HttpRequestData

path - String

Throws:

java.lang.Exception

getListenerName

public static java.lang.String getListenerName(java.lang.String appName)

Helper method to return the listener name for a given application name

Parameters:

appName - String

Returns:

String

getRequestFilter

public RouterRequestFilter getRequestFilter()

Returns the request filter instance

Returns:

RouterRequestFilter or null

getInstance

public static ServletHelper getInstance(javax.servlet.ServletContext servletContext)
                                 throws java.lang.Exception

Returns the instance of the servlet helper

Parameters:

servletContext - ServletContext

sourceEncoding - String

Returns:

ServletHelper

Throws:

java.lang.Exception