xlobsessionimpl.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.

                .append(FIELDS)
                .append(") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");

            ps = getConnection().prepareStatement(sb.toString());

            int i = 1;

            ps.setString(i++, this.prefix);
            ps.setString(i++, fei.getEngineId());
            ps.setString(i++, fei.getInitialEngineId());
            ps.setString(i++, fei.getWorkflowDefinitionUrl());
            ps.setString(i++, fei.getWorkflowDefinitionName());
            ps.setString(i++, fei.getWorkflowDefinitionRevision());
            ps.setString(i++, fei.getWorkflowInstanceId());
            ps.setString(i++, fei.getExpressionName());
            ps.setString(i++, fei.getExpressionId());

            final java.io.StringReader reader = 
                new java.io.StringReader(sXml);

            ps.setCharacterStream(i++, reader, sXml.length());

            ps.executeUpdate();
        }
        catch (final Exception e)
        {
            throw new XlobException
                ("update failure for "+fei, e);
        }
        finally 
        {
            close(ps);
            releaseConnection();
        }
    }

    /**
     * Updates or inserts an XML document for a given fei.
     */
    public void remove (final FlowExpressionId fei)
        throws XlobException
    {
        java.sql.PreparedStatement ps = null;

        try
        {
            ps = prepareStatement("DELETE ", fei);

            ps.executeUpdate();
        }
        catch (final Throwable t)
        {
            throw new XlobException("removal failure", t);
        }
        finally
        {
            close(ps);
            releaseConnection();
        }
    }

    /**
     * Finds the document matching precisely the given fei.
     */
    public org.jdom.Document find (final FlowExpressionId fei)
        throws XlobException
    {
        java.sql.ResultSet rs = null;

        try
        {
            rs = doQuery(null, fei);

            toNext(rs);

            return extract(rs);
        }
        finally
        {
            close(rs);
            releaseConnection();
        }
    }

    /**
     * Retrieves the corresponding XML doc and turns it into its original
     * bean (openwfe.org.xml.XmlCoder).
     */
    public Object findBean (final FlowExpressionId fei)
        throws XlobException
    {
        try
        {
            return XmlCoder.decode(find(fei).getRootElement());
        }
        catch (final XmlCodingException xce)
        {
            throw new XlobException("decoding failure", xce);
        }
    }

    /**
     * Will return true if the given fei points to a stored document.
     */
    public boolean isStored (final FlowExpressionId fei)
        throws XlobException
    {
        java.sql.ResultSet rs = null;

        try
        {
            rs = doQuery("count(*)", fei);

            toNext(rs);

            return rs.getInt(1) > 0;
        }
        catch (final java.sql.SQLException se)
        {
            throw new XlobException("failure", se);
        }
        finally
        {
            close(rs);
            releaseConnection();
        }
    }

    /**
     * Given a partial fei (not all fields set), returns a set of
     * matching workitems.
     * The fei fields may contain SQL wildcards...
     */
    public java.util.Set query (final FlowExpressionId fei)
        throws XlobException
    {
        return query(fei, -1);
    }

    /**
     * Given a partial fei (not all fields set), returns a set of
     * matching xml  documents, but no more than a limit count.
     * The fei fields may contain SQL wildcards...
     */
    public java.util.Set query (FlowExpressionId fei, int limit)
        throws XlobException
    {
        java.sql.ResultSet rs = null;

        try
        {
            rs = doQuery(null, fei);

            final java.util.Set set = new java.util.HashSet();

            int count = 0;

            while (toNext(rs))
            {
                if (limit > 0 && count >= limit) break;

                set.add(extract(rs));

                count++;
            }

            return set;
        }
        finally
        {
            close(rs);
            releaseConnection();
        }
    }

    /**
     * Given a partial fei (not all fields set), returns a set of
     * matching workitems.
     * The fei fields may contain SQL wildcards...
     */
    public java.util.Set queryBeans (final FlowExpressionId fei)
        throws XlobException
    {
        return queryBeans(fei, -1);
    }

    /**
     * Given a partial fei (not all fields set), returns a set of
     * matching workitems, but no more than 'limit' count.
     * The fei fields may contain SQL wildcards...
     */
    public java.util.Set queryBeans 
        (final FlowExpressionId fei, final int limit)
    throws 
        XlobException
    {
        java.sql.ResultSet rs = null;

        try
        {
            rs = doQuery(null, fei);

            final java.util.Set set = new java.util.HashSet();

            int count = 0;

            while (toNext(rs))
            {
                if (limit > 0 && count >= limit) break;

                set.add(extractBean(rs));

                count++;
            }

            return set;
        }
        finally
        {
            close(rs);
            releaseConnection();
        }
    }

    /**
     * Given a partial fei returns the count of matching docs.
     * The fei fields may contain SQL wildcards... If fei is null,
     * will return the total count.
     */
    public int count (FlowExpressionId fei)
        throws XlobException
    {
        java.sql.ResultSet rs = null;

        if (fei == null) fei = new FlowExpressionId();

        try
        {
            rs = doQuery("count(*)", fei);

            toNext(rs);

            return rs.getInt(1);
        }
        catch (final java.sql.SQLException se)
        {
            throw new XlobException("count failure", se);
        }
        finally
        {
            close(rs);
            releaseConnection();
        }
    }

    /**
     * Returns a list of all the flow expression ids.
     */
    public java.util.List listExpressionIds ()
        throws XlobException
    {
        final StringBuffer sb = new StringBuffer();

        sb
            .append("SELECT ")
            .append(FEI_FIELDS)
            .append(" FROM xldocument")
            .append(" WHERE prefix = ?");

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

        try
        {
            final java.util.List result = new java.util.ArrayList(50);

            st = getConnection().prepareStatement(sb.toString());

            st.setString(1, getPrefix());

            rs = st.executeQuery();

            while (rs.next())
                result.add(extractExpressionId(rs));

            return result;
        }
        catch (final java.sql.SQLException e)
        {
            throw new XlobException
                ("failed to list expression ids", e);
        }
        finally
        {
            close(rs);
            close(st);
            releaseConnection();
        }
    }

    /**
     * Returns the prefix used by this session.
     */
    public String getPrefix ()
    {
        return this.prefix;
    }

    /**
     * Lists all prefixes (including the one for this 
     * session) used in the current db. 
     */
    public java.util.List listPrefixes ()
        throws XlobException
    {
        java.sql.Statement st = null;
        java.sql.ResultSet rs = null;

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

            rs = st.executeQuery("SELECT prefix FROM xldocument");

            final java.util.List l = new java.util.ArrayList(20);

            while (rs.next())
            {
                l.add(rs.getString(1));
            }

            return l;
        }
        catch (final java.sql.SQLException se)
        {
            throw new XlobException
                ("failed to list prefixes", se);
        }
        finally
        {
            close(st);
            close(rs);
            releaseConnection();
        }
    }

    //
    // STATIC METHODS

    /**
     * A shortcut method for getting an XlobSession.
     */
    public static XlobSession getXlobSession 
        (final java.sql.Connection con, final String prefix)
    {
        final XlobSession s = new XlobSessionImpl();
        s.init(con, prefix);

        return s;
    }

    /**
     * A shortcut method for getting an XlobSession.
     */
    public static XlobSession getXlobSession 
        (final OwfeDataSource ds, final String prefix)
    {
        final XlobSession s = new XlobSessionImpl();
        s.init(ds, prefix);

        return s;
    }

    /**
     * Buils an XlobSession according to the instructions found
     * in the context and in the service params.
     */
    public static XlobSession createSession
        (final ApplicationContext context,
         final java.util.Map serviceParams)
    throws
        ServiceException
    {
        final OwfeDataSource ds = 
            SqlUtils.lookupDataSource(context, serviceParams);

        final String prefix = MapUtils
            .getAsString(serviceParams, P_PREFIX, context.getName());

        return getXlobSession(ds, prefix);
    }

    /**
     * Buils an XlobSession according to the instructions found
     * in the context and in the service params.
     */
    public static XlobSession createSession
        (final String prefix,
         final ApplicationContext context,
         final java.util.Map serviceParams)
    throws
        ServiceException
    {
        final OwfeDataSource ds = 
            SqlUtils.lookupDataSource(context, serviceParams);

        return getXlobSession(ds, prefix);
    }

}