action.java

struts的源代码

    /**
     * Retrieves any existing errors placed in the request by previous actions.  This method could be called instead
     * of creating a <code>new ActionMessages()<code> at the beginning of an <code>Action<code>
     * This will prevent saveErrors() from wiping out any existing Errors
     *
     * @return the Errors that already exist in the request, or a new ActionMessages object if empty.
     * @param request The servlet request we are processing
     * @since Struts 1.2.1
     */
    protected ActionMessages getErrors(HttpServletRequest request) {
        ActionMessages errors =
            (ActionMessages) request.getAttribute(Globals.ERROR_KEY);
        if (errors == null) {
            errors = new ActionMessages();
        }
        return errors;
    }


    /**
     * <p>Return the user's currently selected Locale.</p>
     *
     * @param request The request we are processing
     */
    protected Locale getLocale(HttpServletRequest request) {

        return RequestUtils.getUserLocale(request, null);

    }


	/**
	 * Retrieves any existing messages placed in the request by previous actions.  This method could be called instead
	 * of creating a <code>new ActionMessages()<code> at the beginning of an <code>Action<code>
	 * This will prevent saveMessages() from wiping out any existing Messages
	 *
	 * @return the Messages that already exist in the request, or a new ActionMessages object if empty.
	 * @param request The servlet request we are processing
     * @since Struts 1.2.1
	 */
	protected ActionMessages getMessages(HttpServletRequest request) {
		ActionMessages messages =
			(ActionMessages) request.getAttribute(Globals.MESSAGE_KEY);
		if (messages == null) {
			messages = new ActionMessages();
		}
		return messages;
	}


    /**
     * <p>Return the default message resources for the current module.</p>
     *
     * @param request The servlet request we are processing
     * @since Struts 1.1
     */
    protected MessageResources getResources(HttpServletRequest request) {

        return ((MessageResources) request.getAttribute(Globals.MESSAGES_KEY));

    }


    /**
     * <p>Return the specified message resources for the current module.</p>
     *
     * @param request The servlet request we are processing
     * @param key The key specified in the
     *  <code>&lt;message-resources&gt;</code> element for the
     *  requested bundle
     *
     * @since Struts 1.1
     */
    protected MessageResources getResources(
        HttpServletRequest request,
        String key) {

        // Identify the current module
        ServletContext context = getServlet().getServletContext();
        ModuleConfig moduleConfig =
            ModuleUtils.getInstance().getModuleConfig(request, context);

        // Return the requested message resources instance
        return (MessageResources) context.getAttribute(
            key + moduleConfig.getPrefix());

    }


    /**
     * <p>Returns <code>true</code> if the current form's cancel button was
     * pressed.  This method will check if the <code>Globals.CANCEL_KEY</code>
     * request attribute has been set, which normally occurs if the cancel
     * button generated by <strong>CancelTag</strong> was pressed by the user
     * in the current request.  If <code>true</code>, validation performed
     * by an <strong>ActionForm</strong>'s <code>validate()</code> method
     * will have been skipped by the controller servlet.</p>
     *
     * @param request The servlet request we are processing
     * @see org.apache.struts.taglib.html.CancelTag
     */
    protected boolean isCancelled(HttpServletRequest request) {

        return (request.getAttribute(Globals.CANCEL_KEY) != null);

    }


    /**
     * <p>Return <code>true</code> 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 <code>false</code>
     * under any of the following circumstances:</p>
     * <ul>
     * <li>No session associated with this request</li>
     * <li>No transaction token saved in the session</li>
     * <li>No transaction token included as a request parameter</li>
     * <li>The included transaction token value does not match the
     *     transaction token in the user's session</li>
     * </ul>
     *
     * @param request The servlet request we are processing
     */
    protected boolean isTokenValid(HttpServletRequest request) {

        return token.isTokenValid(request, false);

    }


    /**
     * <p>Return <code>true</code> 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 <code>false</code> under
     * any of the following circumstances:</p>
     * <ul>
     * <li>No session associated with this request</li>
     * <li>No transaction token saved in the session</li>
     * <li>No transaction token included as a request parameter</li>
     * <li>The included transaction token value does not match the
     *     transaction token in the user's session</li>
     * </ul>
     *
     * @param request The servlet request we are processing
     * @param reset Should we reset the token after checking it?
     */
    protected boolean isTokenValid(HttpServletRequest request, boolean reset) {

        return token.isTokenValid(request, reset);

    }


    /**
     * <p>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.</p>
     *
     * @param request The servlet request we are processing
     */
    protected void resetToken(HttpServletRequest request) {

        token.resetToken(request);

    }


    /**
     * <p>Save the specified error messages keys into the appropriate request
     * attribute for use by the &lt;html:errors&gt; tag, if any messages
     * are required. Otherwise, ensure that the request attribute is not
     * created.</p>
     *
     * @param request The servlet request we are processing
     * @param errors Error messages object
     * @deprecated Use saveErrors(HttpServletRequest, ActionMessages) instead.
     * This will be removed after Struts 1.2.
     */
    protected void saveErrors(HttpServletRequest request, ActionErrors errors) {

        this.saveErrors(request,(ActionMessages)errors);
        // :TODO: Remove after Struts 1.2.

    }


    /**
     * <p>Save the specified error messages keys into the appropriate request
     * attribute for use by the &lt;html:errors&gt; tag, if any messages
     * are required. Otherwise, ensure that the request attribute is not
     * created.</p>
     *
     * @param request The servlet request we are processing
     * @param errors Error messages object
     * @since Struts 1.2
     */
    protected void saveErrors(HttpServletRequest request, ActionMessages errors) {

        // Remove any error messages attribute if none are required
        if ((errors == null) || errors.isEmpty()) {
            request.removeAttribute(Globals.ERROR_KEY);
            return;
        }

        // Save the error messages we need
        request.setAttribute(Globals.ERROR_KEY, errors);

    }


    /**
     * <p>Save the specified messages keys into the appropriate request
     * attribute for use by the &lt;html:messages&gt; tag (if
     * messages="true" is set), if any messages are required. Otherwise,
     * ensure that the request attribute is not created.</p>
     *
     * @param request The servlet request we are processing.
     * @param messages The messages to save. <code>null</code> or empty
     * messages removes any existing ActionMessages in the request.
     *
     * @since Struts 1.1
     */
    protected void saveMessages(
        HttpServletRequest request,
        ActionMessages messages) {

        // Remove any messages attribute if none are required
        if ((messages == null) || messages.isEmpty()) {
            request.removeAttribute(Globals.MESSAGE_KEY);
            return;
        }

        // Save the messages we need
        request.setAttribute(Globals.MESSAGE_KEY, messages);
    }


    /**
     * <p>Save the specified messages keys into the appropriate session
     * attribute for use by the &lt;html:messages&gt; tag (if
     * messages="true" is set), if any messages are required. Otherwise,
     * ensure that the session attribute is not created.</p>
     *
     * @param session The session to save the messages in.
     * @param messages The messages to save. <code>null</code> or empty
     * messages removes any existing ActionMessages in the session.
     *
     * @since Struts 1.2
     */
    protected void saveMessages(
        HttpSession session,
        ActionMessages messages) {

        // Remove any messages attribute if none are required
        if ((messages == null) || messages.isEmpty()) {
            session.removeAttribute(Globals.MESSAGE_KEY);
            return;
        }

        // Save the messages we need
        session.setAttribute(Globals.MESSAGE_KEY, messages);
    }


    /**
     * <p>Save the specified error messages keys into the appropriate session
     * attribute for use by the &lt;html:messages&gt; tag (if messages="false") 
     * or &lt;html:errors&gt;, if any error messages are required. Otherwise, 
     * ensure that the session attribute is empty.</p>
     *
     * @param session The session to save the error messages in.
     * @param errors The error messages to save. <code>null</code> or empty
     * messages removes any existing error ActionMessages in the session.
     *
     * @since Struts 1.2.7
     */
    protected void saveErrors(
        HttpSession session,
        ActionMessages errors) {

        // Remove the error attribute if none are required
        if ((errors == null) || errors.isEmpty()) {
            session.removeAttribute(Globals.ERROR_KEY);
            return;
        }

        // Save the errors we need
        session.setAttribute(Globals.ERROR_KEY, errors);
    }


    /**
     * <p>Save a new transaction token in the user's current session, creating
     * a new session if necessary.</p>
     *
     * @param request The servlet request we are processing
     */
    protected void saveToken(HttpServletRequest request) {
        token.saveToken(request);
    }


    /**
     * <p>Set the user's currently selected <code>Locale</code> into their
     * <code>HttpSession</code>.</p>
     *
     * @param request The request we are processing
     * @param locale The user's selected Locale to be set, or null
     *  to select the server's default Locale
     */
    protected void setLocale(HttpServletRequest request, Locale locale) {

        HttpSession session = request.getSession();
        if (locale == null) {
            locale = Locale.getDefault();
        }
        session.setAttribute(Globals.LOCALE_KEY, locale);

    }

}