sitemesh默认提供了一些常用的rule
可以看到其实可以选择
/**
* Extracts the contents of any elements that look like
* <code><content tag='foo'>...</content></code> and write the contents
* to a page property (page.foo).
*
* <p>This is a cheap and cheerful mechanism for embedding multiple components in a
* page that can be used in different places in decorators.</p>
*
* @author Joe Walnes
*/
public class ContentBlockExtractingRule extends BasicBlockRule<String> {
private final ContentProperty propertyToExport;
public ContentBlockExtractingRule(ContentProperty propertyToExport) {
this.propertyToExport = propertyToExport;
}
@Override
protected String processStart(Tag tag) throws IOException {
tagProcessorContext.pushBuffer();
return tag.getAttributeValue("tag", false);
}
@Override
protected void processEnd(Tag tag, String tagId) throws IOException {
propertyToExport.getChild(tagId).setValue(tagProcessorContext.currentBufferContents());
tagProcessorContext.popBuffer();
}
}