FacesContext / ExtrnalContext

javax.faces.context.*

---

import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;

...

ExternalContext ctx = FacesContext.getCurrentInstance().getExternalContext();
HttpServletRequest request = (HttpServletRequest) ctx.getRequest();
Map<String, Object> reqmap = ctx.getRequestMap();
HttpServletResponse response = (HttpServletResponse) ctx.getResponse();
HttpServletSession session = (HttpServletSession) ctx.getSession();
Map<String, Object> sesmap = ctx.getSessionMap();
Flash flash = (Flash)ctx.getFlash();

<f:param> / <f:viewParam>

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<h:commandLink ... actionListener="bean.check" ...>
<f:param name="op" value="google" />

public check(ActionEvent ae) {
this.op = (String) FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("op"); }

<f:metadata>
<h:commandLink action="" >
    <f:param name="var" value="option" />
    <f:viewParam name="var" value="#{managedBean.property}" />
</h:commandLink>