<h:inputText id="username" value="#{mylogin.username}" required="true" />

<h:inputText id="username" value="some_value" required="true" />

FacesContext ctx = FacesContext.getCurrentInstance();
HttpServletRequest request =
      (HttpServletRequest)ctx.getExternalContext().getRequest();
request.getParameter("username");

FacesContext ctx = FacesContext.getCurrentInstance();
HttpServletRequest request =
      (HttpServletRequest)ctx.getExternalContext().getSession(false);

<h:inputText id="username" value="#{mylogin.username}" required="true" />

<h:inputText id="username" value="some_value" required="true" />

FacesContext facesContext = FacesContext
    .getCurrentInstance();
ExternalContext extContext = facesContext
    .getExternalContext();
Map<String, String> params = extContext
    .getRequestParameterMap();

<h:inputText id="username" value="some_value" required="true"
    binding="#{mylogin.usernameField}" />

private UIInput usernameField;

public void setUsernameField(UIInput usernameField) {
    this.usernameField = usernameField;
}
public UIInput getUsernameField() {
    return usernameField;
}

Object value = usernameField.getValue();