AEM:在页面中链接转换/重写

Question

在我目前的项目中,大坝资产被移动到CDN服务器,我在img元素中的当前src属性应该引用相应的cdn服务器映像,而不是大坝中的那个.
例如:我当前的img元素如下所示:
<img src ="/ content/dam/myproject/123.jpg">

我在CDN服务器上有一个相应的123.jpg图像.现在,应该更改src以引用CDN服务器映像.
<img src ="https://cdn-aem.com/content/dam/myproject/123.jpg">

我可以在组件级别更改这个但是我希望使用OSGi服务或其他东西在更全局的层面上进行更改!

有什么投入？

Answer 1

您可以使用Sling Rewriter.这些文档可在Apache Sling网站上找到.我在下面加了一个Sling Transformer样品.您还需要添加配置节点.您可以在ACS Commons Versioned Clientlibs功能中找到其他示例.

添加此Transformer并更新StartElement方法以处理路径更新:

import java.io.IOException;
import java.util.Map;

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.rewriter.ProcessingComponentConfiguration;
import org.apache.sling.rewriter.ProcessingContext;
import org.apache.sling.rewriter.Transformer;
import org.apache.sling.rewriter.TransformerFactory;
import org.osgi.service.component.ComponentContext;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

@Component
@Service
@Property(name="pipeline.type", value="linkrewriter", propertyPrivate=true)
public class LinkRewriterTransformerFactory implements TransformerFactory {

    public Transformer createTransformer() {
        return new LinkRewriterTransformer();
    }

    @Activate
    protected void activate(Map<String, Object> properties) {
    }

    @Deactivate
    protected void deactivate(ComponentContext ctx) {
    }

    private class LinkRewriterTransformer implements Transformer {
        private ContentHandler contentHandler;
        private SlingHttpServletRequest request;

        public void characters(char[] ch, int start, int length) throws SAXException {
            contentHandler.characters(ch, start, length);
        }

        public void dispose() {
        }

        public void endDocument() throws SAXException {
            contentHandler.endDocument();
        }

        public void endElement(String uri, String localName, String qName) throws SAXException {
            contentHandler.endElement(uri, localName, qName);
        }

        public void endPrefixMapping(String prefix) throws SAXException {
            contentHandler.endPrefixMapping(prefix);
        }

        public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
            contentHandler.ignorableWhitespace(ch, start, length);
        }

        public void init(ProcessingContext context, ProcessingComponentConfiguration config) throws IOException {
            request = context.getRequest();
        }

        public void processingInstruction(String target, String data) throws SAXException {
            contentHandler.processingInstruction(target, data);
        }

        public void setContentHandler(ContentHandler handler) {
            this.contentHandler = handler;
        }

        public void setDocumentLocator(Locator locator) {
            contentHandler.setDocumentLocator(locator);
        }

        public void skippedEntity(String name) throws SAXException {
            contentHandler.skippedEntity(name);
        }

        public void startDocument() throws SAXException {
            contentHandler.startDocument();
        }

        public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
            final AttributesImpl attributes = new AttributesImpl(atts);

            final String href = attributes.getValue("href");

            if (href != null) {
                for (int i = 0; i < attributes.getLength(); i++) {
                    if ("href".equalsIgnoreCase(attributes.getQName(i))) {
                        String cdnPath = /* process your path here */;
                        attributes.setValue(i, cdnPath);
                        break;
                    }
                }
            }

            contentHandler.startElement(uri, localName, qName, attributes);
        }

        public void startPrefixMapping(String prefix, String uri) throws SAXException {
            contentHandler.startPrefixMapping(prefix, uri);
        }
    }
}

将此配置节点添加到/apps/myapp/config/rewriter/myapp.xml:

<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:jcr="http://www.jcp.org/jcr/1.0" xmlns:nt="http://www.jcp.org/jcr/nt/1.0"
    jcr:primaryType="nt:unstructured"
    contentTypes="[text/html]"
    enabled="{Boolean}true"
    generatorType="htmlparser"
    order="1"
    paths="[/content/myapp]"
    serializerType="htmlwriter"
    transformerTypes="[linkchecker,linkrewriter]">
    <generator-htmlparser
        jcr:primaryType="nt:unstructured"
        includeTags="[META,/META,A,/A,IMG,AREA,FORM,BASE,LINK,SCRIPT,BODY,/BODY,VIDEO,/VIDEO,ASIDE,/ASIDE,SECTION,/SECTION]"/>
</jcr:root>