a_cmselement.java

cms是开源的框架

                                export = true;
                            }
                        }
                    }

                } catch (Exception e) {
                    // do nothing, set everything to false and log the error
                    if (CmsLog.getLog(this).isWarnEnabled()) {
                        CmsLog.getLog(this).warn(toString()
                            + " could not find out if the element is proxy cacheable", e);
                    }
                }
            }
            if (!m_cacheDirectives.userSetProxyPrivate()) {
                ((CmsCacheDirectives)m_cacheDirectives).setProxyPrivateCacheable(proxyPrivate);
            }
            if (!m_cacheDirectives.userSetProxyPublic()) {
                ((CmsCacheDirectives)m_cacheDirectives).setProxyPublicCacheable(proxyPublic);
            }
            if (!m_cacheDirectives.userSetExport()) {
                ((CmsCacheDirectives)m_cacheDirectives).setExport(export);
            }
        }
        proxySettings.merge(m_cacheDirectives);
        // now for the subelements
        Enumeration elementNames = m_elementDefinitions.getAllElementNames();
        while (elementNames.hasMoreElements()) {
            String name = (String)elementNames.nextElement();
            CmsElementDefinition currentDef = m_elementDefinitions.get(name);
            A_CmsElement currentEle = CmsXmlTemplateLoader.getElementCache().getElementLocator().get(cms, new CmsElementDescriptor(
                currentDef.getClassName(), currentDef.getTemplateName()), parameters);
            currentEle.checkProxySettings(cms, proxySettings, parameters);
        }
    }

    /**
     * Abstract method for getting the content of this element.
     * Element classes may have different implementations for getting
     * the contents. Common tasks of all implementations are checking
     * the variant cache and creating the variant if required.
     * @param elementCache Entry point for the element cache
     * @param cms CmsObject for accessing system resources
     * @param elDefs Definitions of this element's subelements
     * @param parameters All parameters of this request
     * @param methodparameter used only for methode elements. Contains the parameter for the methode.
     * @return Byte array with the processed content of this element.
     * @throws CmsException
     */
    public abstract byte[] getContent(CmsElementCache elementCache, CmsObject cms,
        CmsElementDefinitionCollection efDefs, String elementName, Hashtable parameters,
        String methodParameter) throws CmsException;

    /**
     * Get a template class from the template class manager.
     * @param cms CmsObject for accessing system resources.
     * @param classname Name of the requested class.
     * @throws CmsException if the loaded class is no OpenCms template class
     */
    protected I_CmsTemplate getTemplateClass(CmsObject cms, String classname) throws CmsException {

        Object o = CmsTemplateClassManager.getClassInstance(classname);
        // Check, if the loaded class really is a OpenCms template class.
        if (o instanceof I_CmsTemplate) {
            return (I_CmsTemplate)o;
        } else {
            throw new CmsLegacyException(classname + " is no OpenCms template class.",
                CmsLegacyException.C_XML_NO_TEMPLATE_CLASS);
        }
    }

    /**
     * Resolve given variant of this element and get content of all sub elements.<p>
     * 
     * @param cms CmsObject for accessing system resources
     * @param variant Variant that should be resolved
     * @param elementCache Entry point for element cache
     * @param elDefs Definitions for all subelements
     * @param parameters All parameters of this request
     * @return Byte array with processed element content
     * @throws CmsException if resolving fails.
     */
    public byte[] resolveVariant(CmsObject cms, CmsElementVariant variant,
        CmsElementCache elementCache, CmsElementDefinitionCollection elDefs, Hashtable parameters)
    throws CmsException {

        boolean resolveDebug = false;
        if (resolveDebug)
            System.err.println("= Start resolving variant " + variant);
        int len = variant.size();
        // Try to get the corresponding element using the element locator
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            for (int i = 0; i < len; i++) {
                // put the name of the element into the params
                if (resolveDebug)
                    System.err.print("= Part " + i + " is a ");
                Object o = variant.get(i);
                // Decide what to do with the current part.
                // If it's a String or byte array, just print it out.
                // If it's a link to a sub element, get this element and call its getContent() method
                if (o instanceof String) {
                    if (resolveDebug)
                        System.err.println("String");
                    baos.write(((String)o).getBytes(cms.getRequestContext().getEncoding()));
                } else if (o instanceof byte[]) {
                    if (resolveDebug)
                        System.err.println("byte array");
                    baos.write((byte[])o);
                } else if (o instanceof CmsElementLink) {
                    if (resolveDebug)
                        System.err.println("Element Link");

                    // we have to resolve the element link right NOW!
                    // Look for the element definition
                    String lookupName = ((CmsElementLink)o).getElementName();
                    if (resolveDebug)
                        System.err.println("= Trying to resolve link \"" + lookupName + "\".");
                    CmsElementDefinition elDef = elDefs.get(lookupName);
                    if (elDef != null) {
                        // We have successfully found an element definition.
                        // first add the parameter from the elementdefinition to the parameters
                        elDef.joinParameters(parameters);
                        // put the name of the element into the params
                        parameters.put("_ELEMENT_", elDef.getName());
                        if (elDef.getTemplateName() != null) {
                            parameters.put(elDef.getName() + "._TEMPLATE_", elDef.getTemplateName());
                        }
                        parameters.put(elDef.getName() + "._CLASS_", elDef.getClassName());
                        if (elDef.getTemplateSelector() != null) {
                            parameters.put(elDef.getName() + "._TEMPLATESELECTOR_", elDef.getTemplateSelector());
                        } else {
                            parameters.put(elDef.getName() + "._TEMPLATESELECTOR_", "default");
                        }
                        // Try to get the corresponding element using the element locator
                        A_CmsElement subEl = elementCache.getElementLocator().get(cms, elDef.getDescriptor(), parameters);
                        if (resolveDebug)
                            System.err.println("= Element defintion for \"" + lookupName
                                + "\" says: ");
                        if (resolveDebug)
                            System.err.println("= -> Class    : " + elDef.getClassName());
                        if (resolveDebug)
                            System.err.println("= -> Template : " + elDef.getTemplateName());
                        String errorMessage = "";
                        if (subEl != null) {
                            // An element could be found. Very fine.
                            // So we can go on and call its getContent() method
                            if (resolveDebug)
                                System.err.println("= Element object found for \"" + lookupName
                                    + "\". Calling getContent on this object. ");
                            byte[] buffer = null;
                            try {
                                buffer = subEl.getContent(elementCache, cms, elDefs, lookupName, parameters, null);
                            } catch (Exception e) {
                                // An error occured while getting the element's content.
                                // Do some error handling here.
                                if (CmsUser.USER_TYPE_SYSTEMUSER == cms.getRequestContext().currentUser().getType()
                                    && !OpenCms.getDefaultUsers().getUserGuest().equals(cms.getRequestContext().currentUser().getName())) {
                                    // a systemuser gets the real message.(except guests)
                                    errorMessage = e.toString();
                                }
                                subEl = null;
                                buffer = null;
                                if (e instanceof CmsException) {
                                    CmsException ce = (CmsException)e;
                                    if (ce instanceof CmsSecurityException) {
                                        if (CmsLog.getLog(this).isErrorEnabled()) {
                                            CmsLog.getLog(this).error("Access denied in element "
                                                + lookupName, ce);
                                        }
                                        throw ce;
                                    } else {
                                        // Any other CmsException. This may be critical
                                        if (CmsLog.getLog(this).isErrorEnabled()) {
                                            CmsLog.getLog(this).error("Error in element "
                                                + lookupName, e);
                                        }
                                    }
                                } else {
                                    // Any other Non-CmsException.
                                    if (CmsLog.getLog(this).isErrorEnabled()) {
                                        CmsLog.getLog(this).error("Non-CmsException in element "
                                            + lookupName, e);
                                    }
                                }
                            }
                            // If we have some results print them out.
                            if (buffer != null) {
                                baos.write(buffer);
                            }
                        } else {
                            // The subelement object is null, i.e. the element could not be found.
                            // Do nothing but a little bit logging here.
                            if (resolveDebug)
                                System.err.println("= Cannot find Element object for \""
                                    + lookupName + "\". Ignoring this link. ");
                            if (CmsLog.getLog(this).isWarnEnabled()) {
                                CmsLog.getLog(this).warn("Cannot find Element object for \""
                                    + lookupName + "\", ignoring this link");
                            }
                        }

                        // If the element could not be generated properly, print a little error
                        // message instead of the element's results.
                        if (subEl == null) {
                            baos.write(("[" + lookupName + "] ??? ").getBytes());
                            baos.write(errorMessage.getBytes());
                        }
                    } else {
                        // No element definition could be found.
                        // Do some logging only and ignore this element
                        baos.write(("[" + lookupName + "] Element not defined.").getBytes());
                        if (CmsLog.getLog(this).isWarnEnabled()) {
                            CmsLog.getLog(this).warn("No element definition found for \""
                                + lookupName + "\", ignoring this link");
                        }
                        if (resolveDebug) {
                            System.err.println("= No element definition found for \"" + lookupName
                                + "\". Ignoring this link. ");
                            System.err.println(elDefs.toString());
                        }
                    }
                } else if (o instanceof CmsMethodLink) {
                    if (resolveDebug)
                        System.err.println("Method Link");
                    // get the methodelement
                    String methodName = ((CmsMethodLink)o).getMethodeName();
                    String methodParameter = ((CmsMethodLink)o).getMethodParameter();
                    A_CmsElement metEle = elementCache.getElementLocator().get(cms, new CmsElementDescriptor(
                        m_className + "." + methodName, "METHOD"), parameters);
                    byte[] buffer = null;
                    if (metEle != null) {
                        try {
                            buffer = metEle.getContent(elementCache, cms, elDefs, null, parameters, methodParameter);
                        } catch (Exception e) {
                            if (e instanceof CmsException) {
                                if (CmsLog.getLog(this).isErrorEnabled()) {
                                    CmsLog.getLog(this).error("Error in method " + methodName, e);
                                }
                            } else {
                                // Any other Non-CmsException.
                                if (CmsLog.getLog(this).isErrorEnabled()) {
                                    CmsLog.getLog(this).error("Non-CmsException in method "
                                        + methodName, e);
                                }
                            }
                        }
                    } else {
                        // The subelement object is null, i.e. the element could not be found.
                        // Do nothing but a little bit logging here.
                        if (resolveDebug)
                            System.err.println("= Cannot find methodElemtn object for \""
                                + methodName + "\". Ignoring this link. ");
                        if (CmsLog.getLog(this).isWarnEnabled()) {
                            CmsLog.getLog(this).warn("Cannot find method Element object for \""
                                + methodName + "\", ignoring this link");
                        }
                    }
                    // If we have some results print them out.
                    if (buffer != null) {
                        baos.write(buffer);
                    }
                }
            }
            return baos.toByteArray();
        } catch (IOException e) {
            // Something went wrong while writing to the OutputStream
            if (CmsLog.getLog(this).isErrorEnabled()) {
                CmsLog.getLog(this).error("IOException while writing to XMl template OutputStream", e);
            }
            throw new CmsLegacyException(CmsLegacyException.C_UNKNOWN_EXCEPTION, e);
        }
    }

    /**
     * Get a string representation of this element.
     * @return String representation.
     */
    public String toString() {

        String part1 = getClass().getName();
        part1 = part1.substring(part1.lastIndexOf(".") + 1);

        String part2 = m_className.substring(m_className.lastIndexOf(".") + 1);
        String part3 = "";
        if (m_templateName != null) {
            part3 = m_templateName.substring(m_templateName.lastIndexOf("/") + 1);
        }

        return "[" + part1 + " (" + part2 + "/" + part3 + ")]";
    }
}