xmlworkitemcoder.java

一个工作流设计及定义的系统,可以直接与数据库结合进行系统工作流程的定义及应用.

        else
            elt = new org.jdom.Element(CLOSED_FILTER);

        WicUtils.setAttribute(elt, NAME, f.getName());
        WicUtils.setAttribute(elt, ADD_ALLOWED, ""+f.isAddAllowed());
        WicUtils.setAttribute(elt, REMOVE_ALLOWED, ""+f.isRemoveAllowed());
        
        encodeEntryList(elt, f);

        return elt;
    }

    protected void encodeEntryList (org.jdom.Element result, Filter f)
    {
        if (f.getEntries() == null || f.getEntries().size() < 1)
        {
            //log.debug("encodePatternList() - list is empty");
            return;
        }

        java.util.Iterator it = f.getEntries().iterator();
        while (it.hasNext())
        {
            FilterEntry entry = (FilterEntry)it.next();

            if (entry.getPermissions().trim().equals("")) continue;
                // do not add 'hidden' fields

            org.jdom.Element elt = new org.jdom.Element(FIELD);

            elt.setAttribute(REGEX, entry.getFieldRegex());
            elt.setAttribute(PERMISSIONS, entry.getPermissions());

            //if (entry.getAttributeType() != null)
            //    elt.setAttribute(TYPE, entry.getAttributeType());

            result.addContent(elt);
        }
    }

    //
    // DECODING
    //

    /*
     * This method prefetches any workitem out of its inputStream...
     * So socket timeout isn't reached...
     * /
    private java.io.Reader prefetch (final java.io.InputStream is)
        throws java.io.IOException
    {
        final java.io.BufferedReader br = new java.io.BufferedReader
            (new java.io.InputStreamReader(is, Utils.getCharset()));

        StringBuffer sXml = new StringBuffer();
        String line = null;

        while (true)
        {
            line = br.readLine();
                //
                // edt : exception thrown here...
                // IOException : "Underlying input stream returned zero bytes"

            if (line == null)
            { 
                //log.debug("prefetch() line is null. Breaking.");
                break;
            }

            sXml.append(line);
            sXml.append('\n');

            //log.debug("prefetch() line is )"+line+"(");

            if (line.indexOf("</"+CANCELITEM+">") > -1 ||
                line.indexOf("</"+WORKITEM+">") > -1 ||
                line.indexOf("</"+LAUNCHITEM+">") > -1)
            {
                break;
            }
        }

        //java.io.ByteArrayInputStream bais = new java.io.ByteArrayInputStream
        //    (sXml.toString().getBytes());
        java.io.ByteArrayInputStream bais = new java.io.ByteArrayInputStream
            (sXml.toString().getBytes(Utils.getEncoding()));

        return new java.io.InputStreamReader(bais, Utils.getEncoding());
    }
     */

    protected org.jdom.Document fetchDocument (final Object o)
        throws CodingException
    {

        log.debug("fetchDocument() instance of "+o.getClass().getName());

        //
        // turn anything into an input stream

        java.io.InputStream stream = null;
        java.io.Reader reader = null;

        try
        {
            if (o instanceof java.io.Reader)
            {
                reader = (java.io.Reader)o;
            }
            else if (o instanceof java.io.File)
            {
                reader = new java.io.FileReader((java.io.File)o);
            }
            else if (o instanceof String)
            {
                reader = new java.io.StringReader((String)o);
            }
            else if (o instanceof java.io.InputStream)
            {
                //reader = prefetch((java.io.InputStream)o);

                //reader = new java.io.InputStreamReader
                //    ((java.io.InputStream)o, Utils.getCharset());

                stream = (java.io.InputStream)o;
            }
            else if (o instanceof java.net.URL)
            {
                //reader = new java.io.InputStreamReader
                //    (((java.net.URL)o).openStream());

                stream = ((java.net.URL)o).openStream();
            }
            else if (o instanceof org.jdom.Document)
            {
                return (org.jdom.Document)o;
            }
            else if (o instanceof org.jdom.Element)
            {
                return (org.jdom.Document)((org.jdom.Element)o).getParent();
            }
            /*
            else if (o instanceof java.nio.channels.ReadableByteChannel)
            {
                reader = NetUtils.channelToReader
                    ((java.nio.channels.ReadableByteChannel)o);
            }
            */
            else
            {
                throw new CodingException
                    ("Cannot decode "+o.getClass().getName());
            }
        }
        catch (final Throwable t)
        {
            throw new CodingException
                ("Failed to decode workitem", t);
        }

        //log.debug("fetchDocument() reader ready");

        //
        // generate xml doc
        
        final org.jdom.input.SAXBuilder builder = 
            new org.jdom.input.SAXBuilder();

        org.jdom.Document doc = null;
        try
        {
            if (stream != null) 
                doc = builder.build(stream);
            else
                doc = builder.build(reader);
        }
        catch (final Throwable t)
        {
            throw new CodingException
                ("Failed to decode incoming workitem with SAX", t);
        }
        finally
        {
            try
            {
                if (stream != null) stream.close();
                if (reader != null) reader.close();
            }
            catch (final Throwable t)
            {
                // ignore
            }
        }

        //log.debug("fetchDocument() document built");

        return doc;
    }

    public WorkItem decode 
        (final Object o,
         final ApplicationContext context,
         final java.util.Map serviceParams) 
    throws 
        CodingException
    {

        log.debug("decode()");

        org.jdom.Document doc = fetchDocument(o);

        org.jdom.Element rootElt = doc.getRootElement();

        //
        // determine type of workitem
        
        WorkItem wi = null;

        log.debug("decode() rootElt is >"+rootElt.getName()+"<");
        
        if (rootElt.getName().equals(WORKITEM))
        {
            wi = decodeInFlowWorkItem(rootElt);
        }
        else if (rootElt.getName().equals(LAUNCHITEM))
        {
            wi = decodeLaunchItem(rootElt);
        }
        else if (rootElt.getName().equals(CANCELITEM))
        {
            wi = decodeCancelItem(rootElt);
        }
        else
        {
            throw new CodingException
                ("Cannot handle elements named '"+
                 rootElt.getName()+"' as workitems");
        }

        decodeWorkItem(wi, rootElt);

        //
        // return result
        
        return wi;
    }

    /**
     * Decoding a FlowExpressionId out of XML.
     */
    public FlowExpressionId decodeFlowExpressionId (final org.jdom.Element elt)
    {
        FlowExpressionId fei = new FlowExpressionId();

        fei.setEngineId
            (elt.getAttributeValue(ENGINE_ID));
        fei.setInitialEngineId
            (elt.getAttributeValue(INITIAL_ENGINE_ID));
        fei.setWorkflowDefinitionUrl
            (elt.getAttributeValue(WORKFLOW_DEFINITION_URL));
        fei.setWorkflowDefinitionName
            (elt.getAttributeValue(WORKFLOW_DEFINITION_NAME));
        fei.setWorkflowDefinitionRevision
            (elt.getAttributeValue(WORKFLOW_DEFINITION_REVISION));
        fei.setExpressionName
            (elt.getAttributeValue(EXPRESSION_NAME));

        fei.setWorkflowInstanceId
            (elt.getAttributeValue(WORKFLOW_INSTANCE_ID));
        fei.setExpressionId
            (elt.getAttributeValue(EXPRESSION_ID));

        return fei;
    }

    protected void decodeWorkItem 
        (final WorkItem target, final org.jdom.Element elt)
    throws 
        CodingException
    {
        
        log.debug("decodeworkItem()");

        target.setLastModified
            (elt.getAttributeValue(LAST_MODIFIED));

        //log.debug("decodeWorkItem() got 'lastModified'");

        //
        // parse attributes
        
        org.jdom.Element attElt = elt.getChild(ATTRIBUTES);
        if (attElt != null)
        {
            attElt = attElt.getChild(SMAP);

            if (attElt != null)
            {
                AttributeCoder coder = getAttributeCoder(SMAP);

                target.setAttributes((StringMapAttribute)coder
                    .decode(attElt, null));
            }
        }
    }

    protected InFlowWorkItem decodeInFlowWorkItem (org.jdom.Element elt)
        throws CodingException
    {
        InFlowWorkItem wi = new InFlowWorkItem();

        org.jdom.Element leiElt = elt.getChild(LAST_EXPRESSION_ID);
        if (leiElt != null)
        {
            leiElt = leiElt.getChild(FLOW_EXPRESSION_ID);
            wi.setLastExpressionId(decodeFlowExpressionId(leiElt));
        }

        wi.setParticipantName(elt.getAttributeValue(PARTICIPANT_NAME));
        wi.setDispatchTime(elt.getAttributeValue(DISPATCH_TIME));

        //
        // decode filter

        wi.setFilter(decodeFilter(elt));

        //
        // decode history
        
        wi.setHistory(decodeHistory(elt));


        return wi;
    }

    protected CancelItem decodeCancelItem (org.jdom.Element elt)
        throws CodingException
    {
        CancelItem ci = new CancelItem();

        org.jdom.Element eiElt = elt.getChild(LAST_EXPRESSION_ID);
        if (eiElt != null)
        {
            eiElt = eiElt.getChild(FLOW_EXPRESSION_ID);
            ci.setLastExpressionId(decodeFlowExpressionId(eiElt));
        }

        ci.setParticipantName(elt.getAttributeValue(PARTICIPANT_NAME));

        return ci;
    }

    protected java.util.List decodeHistory (final org.jdom.Element elt)
    {
        java.util.List history = new java.util.ArrayList(7);

        org.jdom.Element hElt = elt.getChild(HISTORY);
        if (hElt == null) return history;

        java.util.Iterator it = hElt.getChildren(HISTORY_ITEM).iterator();
        while (it.hasNext())
            history.add(decodeHistoryItem((org.jdom.Element)it.next()));

        return history;
    }

    protected HistoryItem decodeHistoryItem (org.jdom.Element elt)
    {
        HistoryItem item = new HistoryItem();

        item.setDate(elt.getAttributeValue(DATE));
        item.setAuthor(elt.getAttributeValue(AUTHOR));
        item.setHost(elt.getAttributeValue(HOST));
        item.setText(elt.getTextTrim());

        item.setWorkflowDefinitionName
            (elt.getAttributeValue(WORKFLOW_DEFINITION_NAME));
        item.setWorkflowDefinitionRevision
            (elt.getAttributeValue(WORKFLOW_DEFINITION_REVISION));
        try
        {
            item.setWorkflowInstanceId
                (elt.getAttributeValue(WORKFLOW_INSTANCE_ID));
        }
        catch (NumberFormatException nfe)
        {
            // let workflow instance id to -1
        }

        item.setExpressionId(elt.getAttributeValue(EXPRESSION_ID));

        return item;
    }

    protected Filter decodeFilter (org.jdom.Element elt)
    {
        org.jdom.Element filterElt = elt.getChild(CLOSED_FILTER);
        if (filterElt == null) filterElt = elt.getChild(OPEN_FILTER);

        if (filterElt == null) return null; // no filter at all

        Filter filter = new Filter();

        if (filterElt.getName().equals(OPEN_FILTER))
            filter.setType(Filter.TYPE_OPEN);
        else
            filter.setType(Filter.TYPE_CLOSED);

        filter.setName(filterElt.getAttributeValue(NAME));
        //log.debug("*********** FilterName >"+filter.getName()+"<");

        String s = filterElt.getAttributeValue(ADD_ALLOWED);
        //log.debug("*********** AddAllowed ? >"+s+"<");
        filter.setAddAllowed
            (s != null && s.trim().toLowerCase().equals("true"));

        s = filterElt.getAttributeValue(REMOVE_ALLOWED);
        //log.debug("*********** RemoveAllowed ? >"+s+"<");
        filter.setRemoveAllowed
            (s != null && s.trim().toLowerCase().equals("true"));

        filter.setEntries(decodeEntryList(filterElt));

        return filter;
    }

    protected java.util.List decodeEntryList (org.jdom.Element filterElt)
    {
        java.util.List result = new java.util.ArrayList();

        java.util.Iterator it = filterElt.getChildren(FIELD).iterator();
        while (it.hasNext())
        {
            org.jdom.Element elt = (org.jdom.Element)it.next();

            String fieldRegex = elt.getAttributeValue(REGEX).trim();
            String permissions = elt.getAttributeValue(PERMISSIONS).trim();

            //String type = elt.getAttributeValue(TYPE);

            FilterEntry entry = 
                new FilterEntry(fieldRegex, permissions/*, type*/);

            result.add(entry);
        }
        
        return result;
    }

    protected LaunchItem decodeLaunchItem (org.jdom.Element elt)
        throws CodingException
    {
        LaunchItem li = new LaunchItem();

        //
        // decode wfdUrl

        li.setWorkflowDefinitionUrl
            (elt.getAttributeValue(WORKFLOW_DEFINITION_URL)); 

        //
        // decode description map
        
        org.jdom.Element dmElt = elt.getChild(DESCRIPTION_MAP);

        if (dmElt != null && dmElt.getChild(SMAP) != null)
        {
            //log.debug("parsing launchitem description map");

            dmElt = dmElt.getChild(SMAP);

            AttributeCoder coder = getAttributeCoder(SMAP);

            StringMapAttribute smap = (StringMapAttribute)coder
                .decode(dmElt, null);

            li.setDescriptionMap(smap);
        }

        return li;
    }

    //
    // STATIC METHODS

}