Get previous URL in JSF/EL

#{facesContext.getExternalContext().getRequest().getHeader("Referer")}

URL demarcation in JSF

http://localhost:8080/APP/dir/page.xhtml?param=1

• #{facesContext.externalContext.request.contextPath}: /APP (ref)
• #{facesContext.externalContext.request.requestURI}: /APP/dir/page.xhtml
• #{facesContext.externalContext.request.queryString}: param=1
• #{facesContext.externalContext.request.requestURL}: http://localhost:8080/APP/dir/page.xhtml
• #{facesContext.externalContext.request.servletPath}, #{facesContext.viewRoot.viewId}: /dir/page.xhtml
• #{facesContext.externalContext.request.scheme}: http
• #{facesContext.externalContext.request.serverName}: localhost
• #{facesContext.externalContext.request.serverPort}: 8080

References

http://download.oracle.com/docs/cd/E17802_01/products/products/servlet/2.5/docs/servlet-2_5-mr2/javax/servlet/http/HttpServletRequest.html#getHeader%28java.lang.String%29