有没有办法在render阶段动态组合/压缩所有h：outputStylesheet资源，然后组合/压缩所有h：outputScript资源？组合/压缩的资源可能需要使用基于组合资源字符串或其它内容的键进行缓存，以避免过度处理。
如果不存在此功能，则我想着手解决这个问题。有人对实现这样的功能有什么好的建议吗？Servlet过滤器可能会起作用，但是过滤器必须执行比必要更多的工作-- 基本上检查整个渲染输出并替换匹配项。似乎在render阶段实现某些东西会更好，因为所有静态资源都可用而不必解析整个输出。
感谢任何建议！
编辑：为了证明我不懒惰，并将真正遵循一些指导来解决这个问题，这是一个捕获脚本资源名称/库然后从视图中删除它们的存根。如您所见，我对接下来该做什么有些困惑...我应该发出http请求获取要组合的资源，然后将它们组合并保存到资源缓存中吗？
package com.davemaple.jsf.listener;
import java.util.ArrayList;
import java.util.List;
import javax.faces.component.UIComponent;
import javax.faces.component.UIOutput;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import javax.faces.event.PreRenderViewEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;
import org.apache.log4j.Logger;
/**
* A Listener that combines CSS/Javascript Resources
*
* @author David Maple<d@davemaple.com>
*
*/
public class ResourceComboListener implements PhaseListener, SystemEventListener {
private static final long serialVersionUID = -8430945481069344353L;
private static final Logger LOGGER = Logger.getLogger(ResourceComboListener.class);
@Override
public PhaseId getPhaseId() {
return PhaseId.RESTORE_VIEW;
}
/*
* (non-Javadoc)
* @see javax.faces.event.PhaseListener#beforePhase(javax.faces.event.PhaseEvent)
*/
public void afterPhase(PhaseEvent event) {
FacesContext.getCurrentInstance().getViewRoot().subscribeToViewEvent(PreRenderViewEvent.class, this);
}
/*
* (non-Javadoc)
* @see javax.faces.event.PhaseListener#afterPhase(javax.faces.event.PhaseEvent)
*/
public void beforePhase(PhaseEvent event) {
//nothing here
}
/*
* (non-Javadoc)
* @see javax.faces.event.SystemEventListener#isListenerForSource(java.lang.Object)
*/
public boolean isListenerForSource(Object source) {
return (source instanceof UIViewRoot);
}
/*
* (non-Javadoc)
* @see javax.faces.event.SystemEventListener#processEvent(javax.faces.event.SystemEvent)
*/
public void processEvent(SystemEvent event) throws AbortProcessingException {
FacesContext context = FacesContext.getCurrentInstance();
UIViewRoot viewRoot = context.getViewRoot();
List<UIComponent> scriptsToRemove = new ArrayList<UIComponent>();
if (!context.isPostback()) {
for (UIComponent component : viewRoot.getComponentResources(context, "head")) {
if (component.getClass().equals(UIOutput.class)) {
UIOutput uiOutput = (UIOutput) component;
if (uiOutput.getRendererType().equals("javax.faces.resource.Script")) {
String library = uiOutput.getAttributes().get("library").toString();
String name = uiOutput.getAttributes().get("name").toString();
// make https requests to get the resources?
// combine then and save to resource cache?
// insert new UIOutput script?
scriptsToRemove.add(component);
}
}
}
for (UIComponent component : scriptsToRemove) {
viewRoot.getComponentResources(context, "head").remove(component);
}
}
}
}