org.apache.struts.action
Class Action

java.lang.Object
  |
  +--org.apache.struts.action.Action

Direct Known Subclasses:

DefinitionDispatcherAction, DispatchAction, ForwardAction, IncludeAction, NoOpAction, ReloadDefinitionsAction, SwitchAction, TilesAction, ViewDefinitionsAction

public class Action

extends java.lang.Object

An Action is an adapter between the contents of an incoming HTTP request and the corresponding business logic that should be executed to process this request. The controller (ActionServlet) will select an appropriate Action for each request, create an instance (if necessary), and call the perform method.

Actions must be programmed in a thread-safe manner, because the controller will share the same instance for multiple simultaneous requests. This means you should design with the following items in mind:

• Instance and static variables MUST NOT be used to store information related to the state of a particular request. They MAY be used to share global resources across requests for the same action.
• Access to other resources (JavaBeans, session variables, etc.) MUST be synchronized if those resources require protection. (Generally, however, resource classes should be designed to provide their own protection where necessary.

When an Action instance is first created, the controller servlet will call setServlet() with a non-null argument to identify the controller servlet instance to which this Action is attached. When the controller servlet is to be shut down (or restarted), the setServlet() method will be called with a null argument, which can be used to clean up any allocated resources in use by this Action.

Version:

$Revision: 1.1 $ $Date$

Author:

Craig R. McClanahan, David Graham

Field Summary

static java.lang.String	ACTION_SERVLET_KEY Deprecated. Use Globals.ACTION_SERVLET_KEY instead.
static java.lang.String	APPLICATION_KEY Deprecated. Replaced by Globals.MODULE_KEY
static java.lang.String	DATA_SOURCE_KEY Deprecated. Replaced by Globals.DATA_SOURCE_KEY
protected static java.util.Locale	defaultLocale The system default Locale.
static java.lang.String	ERROR_KEY Deprecated. Replaced by Globals.ERROR_KEY
static java.lang.String	EXCEPTION_KEY Deprecated. Replaced by Globals.EXCEPTION_KEY
static java.lang.String	FORM_BEANS_KEY Deprecated. Replaced by collection in ModuleConfig
static java.lang.String	FORWARDS_KEY Deprecated. Replaced by collection in ModuleConfig.
static java.lang.String	LOCALE_KEY Deprecated. Replaced by Globals.LOCALE_KEY
static java.lang.String	MAPPING_KEY Deprecated. Replaced by Globals.MAPPING_KEY
static java.lang.String	MAPPINGS_KEY Deprecated. Replaced by collection in ModuleConfig
static java.lang.String	MESSAGE_KEY Deprecated. Replaced by Globals.MESSAGE_KEY
static java.lang.String	MESSAGES_KEY Deprecated. Use Globals.MESSAGES_KEY instead.
static java.lang.String	MULTIPART_KEY Deprecated. Use Globals.MULTIPART_KEY instead.
static java.lang.String	PLUG_INS_KEY Deprecated. Replaced by Globals.PLUG_INS_KEY
static java.lang.String	REQUEST_PROCESSOR_KEY Deprecated. Use Globals.REQUEST_PROCESSOR_KEY instead.
protected ActionServlet	servlet The controller servlet to which we are attached.
static java.lang.String	SERVLET_KEY Deprecated. Use Globals.SERVLET_KEY instead.
private static TokenProcessor	token An instance of TokenProcessor to use for token functionality.
static java.lang.String	TRANSACTION_TOKEN_KEY Deprecated. Use Globals.TRANSACTION_TOKEN_KEY instead.

Constructor Summary

Action()

Method Summary

ActionForward	execute(ActionMapping mapping, ActionForm form, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Process the specified HTTP request, and create the corresponding HTTP response (or forward to another web component that will create it), with provision for handling exceptions thrown by the business logic.
ActionForward	execute(ActionMapping mapping, ActionForm form, javax.servlet.ServletRequest request, javax.servlet.ServletResponse response) Process the specified non-HTTP request, and create the corresponding non-HTTP response (or forward to another web component that will create it), with provision for handling exceptions thrown by the business logic.
protected java.lang.String	generateToken(javax.servlet.http.HttpServletRequest request) Generate a new transaction token, to be used for enforcing a single request for a particular transaction.
protected javax.sql.DataSource	getDataSource(javax.servlet.http.HttpServletRequest request) Return the default data source for the current module.
protected javax.sql.DataSource	getDataSource(javax.servlet.http.HttpServletRequest request, java.lang.String key) Return the specified data source for the current module.
protected java.util.Locale	getLocale(javax.servlet.http.HttpServletRequest request) Return the user's currently selected Locale.
protected MessageResources	getResources() Deprecated. This method can only return the resources for the default module. Use getResources(HttpServletRequest) to get the resources for the current module.
protected MessageResources	getResources(javax.servlet.http.HttpServletRequest request) Return the default message resources for the current module.
protected MessageResources	getResources(javax.servlet.http.HttpServletRequest request, java.lang.String key) Return the specified message resources for the current module.
ActionServlet	getServlet() Return the controller servlet instance to which we are attached.
protected boolean	isCancelled(javax.servlet.http.HttpServletRequest request) Returns true if the current form's cancel button was pressed.
protected boolean	isTokenValid(javax.servlet.http.HttpServletRequest request) Return true if there is a transaction token stored in the user's current session, and the value submitted as a request parameter with this action matches it.
protected boolean	isTokenValid(javax.servlet.http.HttpServletRequest request, boolean reset) Return true if there is a transaction token stored in the user's current session, and the value submitted as a request parameter with this action matches it.
ActionForward	perform(ActionMapping mapping, ActionForm form, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated. Use the execute() method instead
ActionForward	perform(ActionMapping mapping, ActionForm form, javax.servlet.ServletRequest request, javax.servlet.ServletResponse response) Deprecated. Use the execute() method instead
protected void	resetToken(javax.servlet.http.HttpServletRequest request) Reset the saved transaction token in the user's session.
protected void	saveErrors(javax.servlet.http.HttpServletRequest request, ActionErrors errors) Save the specified error messages keys into the appropriate request attribute for use by the <html:errors> tag, if any messages are required.
protected void	saveMessages(javax.servlet.http.HttpServletRequest request, ActionMessages messages) Save the specified messages keys into the appropriate request attribute for use by the <html:messages> tag (if messages="true" is set), if any messages are required.
protected void	saveToken(javax.servlet.http.HttpServletRequest request) Save a new transaction token in the user's current session, creating a new session if necessary.
protected void	setLocale(javax.servlet.http.HttpServletRequest request, java.util.Locale locale) Set the user's currently selected Locale.
void	setServlet(ActionServlet servlet) Set the controller servlet instance to which we are attached (if servlet is non-null), or release any allocated resources (if servlet is null).
protected java.lang.String	toHex(byte[] buffer) Deprecated. This method will be removed in a release after Struts 1.1.

Methods inherited from class java.lang.Object

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

Field Detail

ACTION_SERVLET_KEY

public static final java.lang.String ACTION_SERVLET_KEY

Deprecated. Use Globals.ACTION_SERVLET_KEY instead.

The context attributes key under which our ActionServlet instance will be stored.

Since:

Struts 1.1

See Also:

Constant Field Values

APPLICATION_KEY

public static final java.lang.String APPLICATION_KEY

Deprecated. Replaced by Globals.MODULE_KEY

The base of the context attributes key under which our ModuleConfig data structure will be stored. This will be suffixed with the actual module prefix (including the leading "/" character) to form the actual attributes key.

For each request processed by the controller servlet, the ModuleConfig object for the module selected by the request URI currently being processed will also be exposed under this key as a request attribute.

Since:

Struts 1.1

See Also:

Constant Field Values

DATA_SOURCE_KEY

public static final java.lang.String DATA_SOURCE_KEY

Deprecated. Replaced by Globals.DATA_SOURCE_KEY

The context attributes key under which our default configured data source (which must implement javax.sql.DataSource) is stored, if one is configured for this module.

See Also:

Constant Field Values

ERROR_KEY

public static final java.lang.String ERROR_KEY

Deprecated. Replaced by Globals.ERROR_KEY

The request attributes key under which your action should store an org.apache.struts.action.ActionErrors object, if you are using the corresponding custom tag library elements.

See Also:

Constant Field Values

EXCEPTION_KEY

public static final java.lang.String EXCEPTION_KEY

Deprecated. Replaced by Globals.EXCEPTION_KEY

The request attributes key under which Struts custom tags might store a Throwable that caused them to report a JspException at runtime. This value can be used on an error page to provide more detailed information about what really went wrong.

See Also:

Constant Field Values

FORM_BEANS_KEY

public static final java.lang.String FORM_BEANS_KEY

Deprecated. Replaced by collection in ModuleConfig

The context attributes key under which our org.apache.struts.action.ActionFormBeans collection is normally stored, unless overridden when initializing our ActionServlet.

See Also:

Constant Field Values

FORWARDS_KEY

public static final java.lang.String FORWARDS_KEY

Deprecated. Replaced by collection in ModuleConfig.

The context attributes key under which our org.apache.struts.action.ActionForwards collection is normally stored, unless overridden when initializing our ActionServlet.

See Also:

Constant Field Values

LOCALE_KEY

public static final java.lang.String LOCALE_KEY

Deprecated. Replaced by Globals.LOCALE_KEY

The session attributes key under which the user's selected java.util.Locale is stored, if any. If no such attribute is found, the system default locale will be used when retrieving internationalized messages. If used, this attribute is typically set during user login processing.

See Also:

Constant Field Values

MAPPING_KEY

public static final java.lang.String MAPPING_KEY

Deprecated. Replaced by Globals.MAPPING_KEY

The request attributes key under which our org.apache.struts.ActionMapping instance is passed.

See Also:

Constant Field Values

MAPPINGS_KEY

public static final java.lang.String MAPPINGS_KEY

Deprecated. Replaced by collection in ModuleConfig

The context attributes key under which our org.apache.struts.action.ActionMappings collection is normally stored, unless overridden when initializing our ActionServlet.

See Also:

Constant Field Values

MESSAGE_KEY

public static final java.lang.String MESSAGE_KEY

Deprecated. Replaced by Globals.MESSAGE_KEY

The request attributes key under which your action should store an org.apache.struts.action.ActionMessages object, if you are using the corresponding custom tag library elements.

Since:

Struts 1.1

See Also:

Constant Field Values

MESSAGES_KEY

public static final java.lang.String MESSAGES_KEY

Deprecated. Use Globals.MESSAGES_KEY instead.

The base of the context attributes key under which our module MessageResources will be stored. This will be suffixed with the actual module prefix (including the leading "/" character) to form the actual resources key.

For each request processed by the controller servlet, the MessageResources object for the module selected by the request URI currently being processed will also be exposed under this key as a request attribute.

See Also:

Constant Field Values

MULTIPART_KEY

public static final java.lang.String MULTIPART_KEY

Deprecated. Use Globals.MULTIPART_KEY instead.

The request attributes key under which our multipart class is stored.

See Also:

Constant Field Values

PLUG_INS_KEY

public static final java.lang.String PLUG_INS_KEY

Deprecated. Replaced by Globals.PLUG_INS_KEY

The base of the context attributes key under which an array of PlugIn instances will be stored. This will be suffixed with the actual module prefix (including the leading "/" character) to form the actual attributes key.

Since:

Struts 1.1

See Also:

Constant Field Values

REQUEST_PROCESSOR_KEY

public static final java.lang.String REQUEST_PROCESSOR_KEY

Deprecated. Use Globals.REQUEST_PROCESSOR_KEY instead.

The base of the context attributes key under which our RequestProcessor instance will be stored. This will be suffixed with the actual module prefix (including the leading "/" character) to form the actual attributes key.

Since:

Struts 1.1

See Also:

Constant Field Values

SERVLET_KEY

public static final java.lang.String SERVLET_KEY

Deprecated. Use Globals.SERVLET_KEY instead.

The context attributes key under which we store the mapping defined for our controller serlet, which will be either a path-mapped pattern (/action/*) or an extension mapped pattern (*.do).

See Also:

Constant Field Values

TRANSACTION_TOKEN_KEY

public static final java.lang.String TRANSACTION_TOKEN_KEY

Deprecated. Use Globals.TRANSACTION_TOKEN_KEY instead.

The session attributes key under which our transaction token is stored, if it is used.

See Also:

Constant Field Values

token

private static TokenProcessor token

An instance of TokenProcessor to use for token functionality.

defaultLocale

protected static java.util.Locale defaultLocale

The system default Locale.

servlet

protected ActionServlet servlet

The controller servlet to which we are attached.

Constructor Detail

Action

public Action()

Method Detail

getServlet

public ActionServlet getServlet()

Return the controller servlet instance to which we are attached.

setServlet

public void setServlet(ActionServlet servlet)

Set the controller servlet instance to which we are attached (if servlet is non-null), or release any allocated resources (if servlet is null).

Parameters:

servlet - The new controller servlet, if any

execute

public ActionForward execute(ActionMapping mapping,
                             ActionForm form,
                             javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response)
                      throws java.lang.Exception

Process the specified non-HTTP request, and create the corresponding non-HTTP response (or forward to another web component that will create it), with provision for handling exceptions thrown by the business logic. Return an ActionForward instance describing where and how control should be forwarded, or null if the response has already been completed.

The default implementation attempts to forward to the HTTP version of this method.

Parameters:

mapping - The ActionMapping used to select this instance

form - The optional ActionForm bean for this request (if any)

request - The non-HTTP request we are processing

response - The non-HTTP response we are creating

Throws:

java.lang.Exception - if the application business logic throws an exception

Since:

Struts 1.1

execute

public ActionForward execute(ActionMapping mapping,
                             ActionForm form,
                             javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response)
                      throws java.lang.Exception

Process the specified HTTP request, and create the corresponding HTTP response (or forward to another web component that will create it), with provision for handling exceptions thrown by the business logic. Return an ActionForward instance describing where and how control should be forwarded, or null if the response has already been completed.

Parameters:

mapping - The ActionMapping used to select this instance

form - The optional ActionForm bean for this request (if any)

request - The HTTP request we are processing

response - The HTTP response we are creating

Throws:

java.lang.Exception - if the application business logic throws an exception

Since:

Struts 1.1

perform

public ActionForward perform(ActionMapping mapping,
                             ActionForm form,
                             javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response)
                      throws java.io.IOException,
                             javax.servlet.ServletException

Deprecated. Use the execute() method instead

Process the specified non-HTTP request, and create the corresponding non-HTTP response (or forward to another web component that will create it). Return an ActionForward instance describing where and how control should be forwarded, or null if the response has already been completed.

The default implementation attempts to forward to the HTTP version of this method.

Parameters:

mapping - The ActionMapping used to select this instance

form - The optional ActionForm bean for this request (if any)

request - The non-HTTP request we are processing

response - The non-HTTP response we are creating

Throws:

java.io.IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet exception occurs

perform

public ActionForward perform(ActionMapping mapping,
                             ActionForm form,
                             javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response)
                      throws java.io.IOException,
                             javax.servlet.ServletException

Deprecated. Use the execute() method instead

Process the specified HTTP request, and create the corresponding HTTP response (or forward to another web component that will create it). Return an ActionForward instance describing where and how control should be forwarded, or null if the response has already been completed.

Parameters:

mapping - The ActionMapping used to select this instance

form - The optional ActionForm bean for this request (if any)

request - The HTTP request we are processing

response - The HTTP response we are creating

Throws:

java.io.IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet exception occurs

generateToken

protected java.lang.String generateToken(javax.servlet.http.HttpServletRequest request)

Generate a new transaction token, to be used for enforcing a single request for a particular transaction.

Parameters:

request - The request we are processing

getDataSource

protected javax.sql.DataSource getDataSource(javax.servlet.http.HttpServletRequest request)

Return the default data source for the current module.

Parameters:

request - The servlet request we are processing

Since:

Struts 1.1

getDataSource

protected javax.sql.DataSource getDataSource(javax.servlet.http.HttpServletRequest request,
                                             java.lang.String key)

Return the specified data source for the current module.

Parameters:

request - The servlet request we are processing

key - The key specified in the <message-resources> element for the requested bundle

Since:

Struts 1.1

getLocale

protected java.util.Locale getLocale(javax.servlet.http.HttpServletRequest request)

Return the user's currently selected Locale.

Parameters:

request - The request we are processing

getResources

protected MessageResources getResources()

Deprecated. This method can only return the resources for the default module. Use getResources(HttpServletRequest) to get the resources for the current module.

Return the message resources for the default module.

getResources

protected MessageResources getResources(javax.servlet.http.HttpServletRequest request)

Return the default message resources for the current module.

Parameters:

request - The servlet request we are processing

Since:

Struts 1.1

getResources

protected MessageResources getResources(javax.servlet.http.HttpServletRequest request,
                                        java.lang.String key)

Return the specified message resources for the current module.

Parameters:

request - The servlet request we are processing

key - The key specified in the <message-resources> element for the requested bundle

Since:

Struts 1.1

isCancelled

protected boolean isCancelled(javax.servlet.http.HttpServletRequest request)

Returns true if the current form's cancel button was pressed. This method will check if the Globals.CANCEL_KEY request attribute has been set, which normally occurs if the cancel button generated by CancelTag was pressed by the user in the current request. If true, validation performed by an ActionForm's validate() method will have been skipped by the controller servlet.

Parameters:

request - The servlet request we are processing

See Also:

CancelTag

isTokenValid

protected boolean isTokenValid(javax.servlet.http.HttpServletRequest request)

Return true if there is a transaction token stored in the user's current session, and the value submitted as a request parameter with this action matches it. Returns false under any of the following circumstances:

• No session associated with this request
• No transaction token saved in the session
• No transaction token included as a request parameter
• The included transaction token value does not match the transaction token in the user's session

Parameters:

request - The servlet request we are processing

isTokenValid

protected boolean isTokenValid(javax.servlet.http.HttpServletRequest request,
                               boolean reset)

Return true if there is a transaction token stored in the user's current session, and the value submitted as a request parameter with this action matches it. Returns false

• No session associated with this request
• No transaction token saved in the session
• No transaction token included as a request parameter
• The included transaction token value does not match the transaction token in the user's session

Parameters:

request - The servlet request we are processing

reset - Should we reset the token after checking it?

resetToken

protected void resetToken(javax.servlet.http.HttpServletRequest request)

Reset the saved transaction token in the user's session. This indicates that transactional token checking will not be needed on the next request that is submitted.

Parameters:

request - The servlet request we are processing

saveErrors

protected void saveErrors(javax.servlet.http.HttpServletRequest request,
                          ActionErrors errors)

Save the specified error messages keys into the appropriate request attribute for use by the <html:errors> tag, if any messages are required. Otherwise, ensure that the request attribute is not created.

Parameters:

request - The servlet request we are processing

errors - Error messages object

saveMessages

protected void saveMessages(javax.servlet.http.HttpServletRequest request,
                            ActionMessages messages)

Save the specified messages keys into the appropriate request attribute for use by the <html:messages> tag (if messages="true" is set), if any messages are required. Otherwise, ensure that the request attribute is not created.

Parameters:

request - The servlet request we are processing

messages - Messages object

Since:

Struts 1.1

saveToken

protected void saveToken(javax.servlet.http.HttpServletRequest request)

Save a new transaction token in the user's current session, creating a new session if necessary.

Parameters:

request - The servlet request we are processing

setLocale

protected void setLocale(javax.servlet.http.HttpServletRequest request,
                         java.util.Locale locale)

Set the user's currently selected Locale.

Parameters:

request - The request we are processing

locale - The user's selected Locale to be set, or null to select the server's default Locale

toHex

protected java.lang.String toHex(byte[] buffer)

Deprecated. This method will be removed in a release after Struts 1.1.

Convert a byte array to a String of hexadecimal digits and return it.

Parameters:

buffer - The byte array to be converted