Error messages on page with the <h:messages> in JSF

Question

I'm creating simple example on JSF. It's small Login application. My problem is duplicate error messages on my page:

I have two h:message(for username and password) tags and one h:messages(global messages) on my page:

<h:form id="loginForm">

   <h:panelGrid columns="3">

       <h:outputText value="Username" />
       <h:inputText id="username" value="#{loginBean.username}" 
                  required="true" requiredMessage="Please enter your username" />
       <h:message for="username" errorClass="errorMessage" /> <!-- Message for username -->

       <h:outputText value="Password" />
       <h:inputSecret id="password" value="#{loginBean.password}" 
                  required="true" requiredMessage="Please enter your password" />
       <h:message for="password" errorClass="errorMessage" /> <!-- Message for password -->


       <h:commandButton value="Login" action="#{loginBean.login}" />

   </h:panelGrid>

   <h:messages styleClass="errorMessage" /> <!-- Global messages -->


</h:form>

Action method login() in my backing bean:

public String login() {
    FacesContext facesContext = FacesContext.getCurrentInstance();
    if ("admin".equals(username) && "pass".equals(password)) {
        return "success";
    } else {
        facesContext.addMessage("loginForm", new FacesMessage("Username or password is incorrect"));
        return null;
    }
}

I want to display message about empty username or password only next to these fields, not under my button in global messages. And I want to print my error message from my action method in global messages if password or username is incorrect. How can I resolve this?

I tried to use the attribute globalOnly:

<h:messages styleClass="errorMessage" globalOnly="true" /> <!-- Global messages -->

but it isn't completely solved my problem, because global messages aren't displayed at all in this case.

Thanks in advance!

Solution

The globalOnly switch should work if you add your messages correctly in your backing bean. The client-id must be null in FacesContext.addMessage(...):

FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(message));