jsf getRequestParameterMap() & getRequestMap()

太晕了，一直以为这两个是同样的方法呢，今天在前台添加了参数<param， 用getRequestMap()死活得不到，才想到查查这两个方法的区别：与JSP的getParameter/getAttribute相同

 

FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap(); FacesContext.getCurrentInstance().getExternalContext().getRequestMap();

 

The first contains all request parameters which are set by the client. The server can get them but cannot change it.
The second contains all request attributes which are set/controlled by the server. The client has no control over it.