Action (Apache Struts API Documentation)
Keywords: org.apache.struts.action.Action,Action class

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## 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: 2003-08-22 09:14:33 +0100 (Fri, 22 Aug 2003) $
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

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

Copyright © 2000-2003 - Apache Software Foundation