public  void addData(ToolInfo info) 
{
        if (validateToolInfo(info))
        {
            appTools.put(info.getKey(), info.getInstance(null));
        }
}

Overrides XMLToolboxManager to put data into appTools map

 public  void addTool(ToolInfo info) 
{
        if (validateToolInfo(info))
        {
            if (info instanceof ServletToolInfo)
            {
                ServletToolInfo sti = (ServletToolInfo)info;
                if (ViewContext.REQUEST.equalsIgnoreCase(sti.getScope()))
                {
                    requestToolInfo.add(sti);
                    return;
                }
                else if (ViewContext.SESSION.equalsIgnoreCase(sti.getScope()))
                {
                    sessionToolInfo.add(sti);
                    return;
                }
                else if (ViewContext.APPLICATION.equalsIgnoreCase(sti.getScope()))
                {
                    /* add application scoped tools to appTools and
                     * initialize them with the ServletContext */
                    appTools.put(sti.getKey(), sti.getInstance(servletContext));
                    return;
                }
                else
                {
                    LOG.warn("Unknown scope '" + sti.getScope() + "' - " + 
                            sti.getKey() + " will be request scoped.");
                    //default is request scope
                    requestToolInfo.add(info);
                }
            }
            else
            {
                //default is request scope
                requestToolInfo.add(info);
            }
        }
}

Overrides XMLToolboxManager to separate tools by scope. For this to work, we obviously override getToolboxContext(Object) as well.

 public static synchronized ServletToolboxManager getInstance(ServletContext servletContext,
    String toolboxFile) 
{
        // little fix up
        if (!toolboxFile.startsWith("/"))
        {
            toolboxFile = "/" + toolboxFile;
        }
        // get config file pathname
        String pathname = servletContext.getRealPath(toolboxFile);
        // check if a previous instance exists
        ServletToolboxManager toolboxManager = 
            (ServletToolboxManager)managersMap.get(pathname);
        if (toolboxManager == null)
        {
            // if not, build one
            InputStream is = null;
            try
            {
                // get the bits
                is = servletContext.getResourceAsStream(toolboxFile);
                if (is != null)
                {
                    LOG.info("Using config file '" + toolboxFile +"'");
                    toolboxManager = new ServletToolboxManager(servletContext);
                    toolboxManager.load(is);
                    // remember it
                    managersMap.put(pathname, toolboxManager);
                    LOG.info("Toolbox setup complete.");
                }
            }
            catch(Exception e)
            {
                LOG.error("Problem loading toolbox '" + toolboxFile +"' : " + e);
                // if this happens, it probably deserves
                // to have the stack trace logged
                StringWriter sw = new StringWriter();
                e.printStackTrace(new PrintWriter(sw));
                LOG.error(sw.toString());
            }
            finally
            {
                try
                {
                    if (is != null)
                    {
                        is.close();
                    }
                }
                catch(Exception ee) {}
            }
        }
        return toolboxManager;
}

ServletToolboxManager factory method. This method will ensure there is exactly one ServletToolboxManager per xml toolbox configuration file.

 protected Object getMutex(HttpSession session) 
{
        // yes, this uses double-checked locking, but it is safe here
        // since partial initialization of the lock is not an issue
        Object lock = session.getAttribute("session.mutex");
        if (lock == null)
        {
            // one thread per toolbox manager at a time
            synchronized(this)
            {
                // in case another thread already came thru
                lock = session.getAttribute("session.mutex");
                if (lock == null)
                {
                    // use a Boolean because it is serializable and small
                    lock = new Boolean(true);
                    session.setAttribute("session.mutex", lock);
                }
            }
        }
        return lock;
}

Returns a mutex (lock object) unique to the specified session to allow for reliable synchronization on the session.

 protected RuleSet getRuleSet() 
{
        return servletRuleSet;
}

Retrieves the rule set Digester should use to parse and load the toolbox for this manager.

The DTD corresponding to the ServletToolboxRuleSet is:

<?xml version="1.0"?>
<!ELEMENT toolbox (create-session?,xhtml?,tool*,data*,#PCDATA)>
<!ELEMENT create-session (#CDATA)>
<!ELEMENT xhtml (#CDATA)>
<!ELEMENT tool (key,scope?,class,parameter*,#PCDATA)>
<!ELEMENT data (key,value)>
<!ATTLIST data type (string|number|boolean) "string">
<!ELEMENT key (#CDATA)>
<!ELEMENT scope (#CDATA)>
<!ELEMENT class (#CDATA)>
<!ELEMENT parameter (EMPTY)>
<!ATTLIST parameter name CDATA #REQUIRED>
<!ATTLIST parameter value CDATA #REQUIRED>
<!ELEMENT value (#CDATA)>

 public Map getToolbox(Object initData) 
{
        //we know the initData is a ViewContext
        ViewContext ctx = (ViewContext)initData;
        //create the toolbox map with the application tools in it
        Map toolbox = new HashMap(appTools);
        if (!sessionToolInfo.isEmpty())
        {
            HttpSession session = ctx.getRequest().getSession(createSession);
            if (session != null)
            {
                // allow only one thread per session at a time
                synchronized(getMutex(session))
                {
                    // get the session tools
                    Map stmap = (Map)session.getAttribute(SESSION_TOOLS_KEY);
                    if (stmap == null)
                    {
                        // init and store session tools map
                        stmap = new HashMap(sessionToolInfo.size());
                        Iterator i = sessionToolInfo.iterator();
                        while(i.hasNext())
                        {
                            ToolInfo ti = (ToolInfo)i.next();
                            stmap.put(ti.getKey(), ti.getInstance(ctx));
                        }
                        session.setAttribute(SESSION_TOOLS_KEY, stmap);
                    }
                    // add them to the toolbox
                    toolbox.putAll(stmap);
                }
            }
        }
        //add and initialize request tools
        Iterator i = requestToolInfo.iterator();
        while(i.hasNext())
        {
            ToolInfo info = (ToolInfo)i.next();
            toolbox.put(info.getKey(), info.getInstance(ctx));
        }
        return toolbox;
}

Overrides XMLToolboxManager to handle the separate scopes. Application scope tools were initialized when the toolbox was loaded. Session scope tools are initialized once per session and stored in a map in the session attributes. Request scope tools are initialized on every request.

 public  void setCreateSession(boolean b) 
{
        createSession = b;
        LOG.debug("create-session is set to " + b);
}

Sets whether or not to create a new session when none exists for the current request and session-scoped tools have been defined for this toolbox.

If true, then a call to #getToolboxContext(Object) will create a new session if none currently exists for this request and the toolbox has one or more session-scoped tools designed.

If false, then a call to getToolboxContext(Object) will never create a new session for the current request. This effectively means that no session-scoped tools will be added to the ToolboxContext for a request that does not have a session object.

The default value is true.

 public  void setXhtml(Boolean value) 
{
        servletContext.setAttribute(ViewContext.XHTML, value);
        LOG.info(ViewContext.XHTML + " is set to " + value);
}

Sets an application attribute to tell velocimacros and tools (especially the LinkTool) whether they should output XHTML or HTML.