sessionimpl.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.

    //
    // METHODS

    protected long generateUniqueId ()
    {
        return ((Long)this.uiGenerator.generateUniqueId()).longValue();
    }

    protected long insert 
        (long xmlDocumentId, String clientId, org.jdom.Document doc)
    throws 
        XdbcException
    {
        java.sql.Statement st = null;

        try
        {
            //log.debug(">>> >>> inserting document");

            if (xmlDocumentId < 0)
                xmlDocumentId = generateUniqueId();

            st = getConnection().createStatement();

            StringBuffer sb = new StringBuffer();
            sb.append("INSERT INTO ");
            sb.append(DOCUMENT);
            sb.append(" (id, clientId) VALUES (");
            sb.append(xmlDocumentId); sb.append(", ");
            sb.append("'"); sb.append(clientId); sb.append("'");
            sb.append(")");
            String s = sb.toString();

            log.debug("insert(doc)   >\n"+s+"\n<");
            log.debug("clientId >"+clientId+"<");

            // 'isReady' is automatically set to 'false'

            st.addBatch(s);

            insert(st, xmlDocumentId, -1, doc.getRootElement(), 0);
                // -1 means no parent element

            st.executeBatch();
            st.close();

            st = getConnection().createStatement();

            sb = new StringBuffer();
            sb.append("UPDATE ");
            sb.append(DOCUMENT);
            sb.append(" SET isReady = 1");

            st.execute(sb.toString());

            //log.debug("<<< <<< document inserted");

            return xmlDocumentId;
        }
        catch (java.sql.SQLException se)
        {
            throw new XdbcException
                ("Failed to insert document", se);
        }
        finally
        {
            try
            {
                releaseConnection();
                st.close();
            }
            catch (Exception e)
            {
                // forget it
            }
        }
    }

    protected void insert 
        (java.sql.Statement st, 
         long documentId, 
         long parentElementId,
         org.jdom.Element elt,
         long order)
    throws 
        java.sql.SQLException
    {
        long id = -1;

        if (parentElementId < 0)
            //
            // if the element is the root element of a document,
            // its id the document id
            // (it saves a column in the xdocument table)
            //
            id = documentId;
        else
            id = generateUniqueId();

        StringBuffer sb = null;
        String s = null;

        Object onlyTextChild = getOnlyTextChild(elt);

        //
        // add element to element table

        sb = new StringBuffer();
        sb.append("INSERT INTO ");
        sb.append(ELEMENT);
        sb.append(" (id, documentId, eTagName, eOrder");
        if (parentElementId > 0) 
        {
            sb.append(", parentElementId");
        }
        if (onlyTextChild != null)
        {
            sb.append(", eText");

            if (onlyTextChild instanceof org.jdom.CDATA)
            {
                sb.append(", eIsCdata");
            }
        }
        sb.append(") VALUES (");
        sb.append(id); sb.append(", ");
        sb.append(documentId); sb.append(", ");
        sb.append("'"); sb.append(elt.getName()); sb.append("', ");
        sb.append(order);
        if (parentElementId > 0)
        {
            sb.append(", ");
            sb.append(parentElementId);
        }
        if (onlyTextChild != null)
        {
            if (onlyTextChild instanceof org.jdom.Text)
            {
                sb.append(", ");
                String text = ((org.jdom.Text)onlyTextChild).getTextTrim();
                text = SqlUtils.prepareString(text);
                sb.append(text);
            }
            else
            {
                sb.append(", ");
                String text = ((org.jdom.CDATA)onlyTextChild).getTextTrim();
                text = SqlUtils.prepareString(text);
                sb.append(text);
                sb.append(", ");
                sb.append("1"); // eIsCdata
            }
        }
        sb.append(")");
        s = sb.toString();

        //log.debug("element >\n"+s+"\n<");

        st.addBatch(s);

        //
        // add attributes
        
        java.util.Iterator it = elt.getAttributes().iterator();
        while (it.hasNext())
        {
            org.jdom.Attribute att = (org.jdom.Attribute)it.next();

            insert(st, documentId, id, att.getName(), att.getValue());
        }

        //
        // add children element
        
        if (onlyTextChild != null) return;
        
        long cOrder = 0;
        
        it = elt.getContent().iterator();
        while (it.hasNext())
        {
            Object o = it.next();

            if (o instanceof org.jdom.Element)
            {
                org.jdom.Element se = (org.jdom.Element)o;

                insert(st, documentId, id, se, cOrder);

                cOrder = cOrder + 1;
            }
            else if (o instanceof org.jdom.Text)
            {
                org.jdom.Text stx = (org.jdom.Text)o;

                insert(st, documentId, id, stx, cOrder);

                cOrder = cOrder + 1;
            }
            else if (o instanceof org.jdom.CDATA)
            {
                org.jdom.CDATA cdt = (org.jdom.CDATA)o;

                insert(st, documentId, id, cdt, cOrder);

                cOrder = cOrder + 1;
            }
            else
            {
                log.info
                    ("skipped jdom content instance of class '"+
                     o.getClass().getName()+"'");
            }
        }
    }

    private Object getOnlyTextChild (org.jdom.Element elt)
    {
        java.util.List content = elt.getContent();

        if (content.size() != 1) return null;

        Object child = content.get(0);

        if (child instanceof org.jdom.Text ||
            child instanceof org.jdom.CDATA)
        {
            return child;
        }

        return null;
    }

    protected void insert 
        (java.sql.Statement st, 
         long documentId, 
         long parentElementId,
         org.jdom.Text text,
         long order)
    throws 
        java.sql.SQLException
    {
        long id = generateUniqueId();

        String sText  = SqlUtils.prepareString(text.getTextTrim());

        StringBuffer sb = new StringBuffer();
        sb.append("INSERT INTO ");
        sb.append(ELEMENT);
        sb.append(" (id, documentId, eText, eOrder, parentElementId");
        sb.append(") VALUES (");
        sb.append(id); sb.append(", ");
        sb.append(documentId); sb.append(", ");
        sb.append(sText); sb.append(", ");
        sb.append(order); sb.append(", ");
        sb.append(parentElementId);
        sb.append(")");
        String s = sb.toString();

        //log.debug("inserting text element >\n"+s+"\n<");

        st.addBatch(s);
    }

    protected void insert 
        (java.sql.Statement st, 
         long documentId, 
         long parentElementId,
         org.jdom.CDATA cdt,
         long order)
    throws 
        java.sql.SQLException
    {
        long id = generateUniqueId();

        StringBuffer sb = new StringBuffer();
        sb.append("INSERT INTO ");
        sb.append(ELEMENT);
        sb.append(" (id, documentId, eText, eOrder, eIsCdata, parentElementId");
        sb.append(") VALUES (");
        sb.append(id); sb.append(", ");
        sb.append(documentId); sb.append(", ");
        sb.append("'"); sb.append(cdt.getTextTrim()); sb.append("', ");
        sb.append(order); sb.append(", ");
        sb.append("1, "); // eIsCdata
        sb.append(parentElementId);
        sb.append(")");
        String s = sb.toString();

        //log.debug("inserting cdata element >\n"+s+"\n<");

        st.addBatch(s);
    }

    protected void insert 
        (java.sql.Statement st, 
         long documentId, 
         long elementId,
         String attributeName, 
         String attributeValue)
    throws 
        java.sql.SQLException
    {
        StringBuffer sb = new StringBuffer();
        sb.append("INSERT INTO ");
        sb.append(ATTRIBUTE);
        sb.append(" (documentId, elementId, attName, attValue");
        sb.append(") VALUES (");
        sb.append(documentId); sb.append(", ");
        sb.append(elementId); sb.append(", ");

        sb.append(SqlUtils.prepareString(attributeName)); 
        sb.append(", ");

        sb.append(SqlUtils.prepareString(attributeValue));

        sb.append(")");
        String s = sb.toString();

        //log.debug("attribute >\n"+s+"\n<");

        st.addBatch(s);
    }
    
    protected java.util.List simpleFind (String query)
        throws XdbcException
    {
        java.sql.Statement st = null;
        java.sql.ResultSet rs = null;

        try
        {
            st = getConnection().createStatement();

            rs = st.executeQuery(query);

            java.util.List result = new java.util.ArrayList();

            while (rs.next())
                result.add(new Long(rs.getLong(1)));

            return result;
        }
        catch (java.sql.SQLException se)
        {
            throw new XdbcException
                ("Failed to find in db", se);
        }
        finally
        {
            try
            {
                releaseConnection();
                rs.close();
                st.close();
            }
            catch (Exception e)
            {
                // forget it
            }
        }
    }

    protected java.sql.Connection getConnection ()
        throws java.sql.SQLException
    {
        if (this.connection != null) return this.connection;

        return this.dataSource.getConnection();
    }

    protected void releaseConnection ()
    {
        if (this.dataSource != null)
            this.dataSource.releaseConnection();
    }

    protected java.util.List find (java.util.List documentIds)
        throws XdbcException
    {
        if (documentIds == null || documentIds.size() < 1)
        {
            log.debug("No documentIds, returning empty list");

            return new java.util.ArrayList(0);
        }

        java.sql.Statement st = null;
        java.sql.ResultSet rs = null;

        try
        {
            st = getConnection().createStatement();

            log.debug("documentIds.size() = "+documentIds.size());

            //
            // prepare XmlObjectMaps
            // and
            // WHERE clause

            StringBuffer sb = new StringBuffer();
            sb.append(" WHERE ");

            java.util.Map documentMap = 
                new java.util.HashMap(documentIds.size());

            //log.debug("built documentMap");

            java.util.Iterator it = documentIds.iterator();
            while (it.hasNext())
            {
                Long documentId = (Long)it.next();

                //
                // XmlObjectMap

                XmlObjectMap map = new XmlObjectMap();
                documentMap.put(documentId, map);

                //
                // WHERE clause

                sb.append("documentId=");
                sb.append(documentId);

                if (it.hasNext()) sb.append(" OR ");
            }

            String whereClause = sb.toString();

            //log.debug("whereClause >\n"+whereClause+"\n<");

            //
            // fetch elements

            sb = new StringBuffer();
            sb.append("SELECT ");
            sb.append("documentId, id, parentElementId, eTagName, eText, eOrder, eIsCdata");
            sb.append(" FROM ");
            sb.append(ELEMENT);
            sb.append(whereClause);
            sb.append(" ORDER BY documentId, parentElementId, eOrder");

            String s = sb.toString();

            //log.debug("fetching elements >\n"+s+"\n<");

            rs = st.executeQuery(s);

            while(rs.next())
            {
                XmlObjectMap map = 
                    (XmlObjectMap)documentMap.get(new Long(rs.getLong(1)));
                map.put(XmlObject.buildElement(rs));
            }

            rs.close();

            //
            // fetch attributes

            sb = new StringBuffer();
            sb.append("SELECT documentId, elementId, attName, attValue FROM ");
            sb.append(ATTRIBUTE);
            sb.append(whereClause);
            sb.append(" ORDER BY documentId");

            s = sb.toString();

            //log.debug("fetching attributes >\n"+s+"\n<");

            rs = st.executeQuery(s);

            while(rs.next())
            {
                XmlObjectMap map = 
                    (XmlObjectMap)documentMap.get(new Long(rs.getLong(1)));
                map.put(XmlObject.buildAttribute(rs));
            }

            rs.close();

            //
            // return documents

            java.util.List result = new java.util.ArrayList(documentIds.size());
            it = documentIds.iterator();
            while (it.hasNext())
            {
                XmlObjectMap map = 
                    (XmlObjectMap)documentMap.get((Long)it.next());
                result.add(map.buildDocument());
            }

            return result;
        }
        catch (java.sql.SQLException se)
        {
            throw new XdbcException
                ("Failed to fetch documents from db", se);
        }
        finally
        {
            try
            {
                releaseConnection();
                st.close();
            }
            catch (Exception e)
            {
                // forget it
            }
        }
    }

    //
    // STATIC METHOD

    public static Session createSession
        (final ApplicationContext context,
         final java.util.Map serviceParams)
    throws
        ServiceException
    {
        final OwfeDataSource ds = 
            SqlUtils.lookupDataSource(context, serviceParams);

        int idPrefix = 10;
        String sIdPrefix = (String)serviceParams
            .get(UniqueIdGenerator.P_ID_PREFIX);
        if (sIdPrefix != null)
            idPrefix = Integer.parseInt(sIdPrefix);

        Session session = null;

        try
        {
            session = new openwfe.org.xdbc.SessionImpl();
            session.init(ds, idPrefix);
        }
        catch (XdbcException xe)
        {
            throw new ServiceException
                ("Failed to set up xdbcSession", xe);
        }

        return session;
    }

}