JSF FacesMessage将不会被呈现

Question

我已经阅读了很多如何添加FacesMessage的指南，但没有任何工作，我不明白为什么?

我总是得到以下警告，但我现在不知道如何修复它?

[Warnung ] There are some unhandled FacesMessages, this means not every FacesMessage had a chance to be rendered.
These unhandled FacesMessages are: 
- Login failed

My JSF View:

    <!-- Login Form -->
        <h:form id="loginForm" role="form" style="width: 400px; margin:0 auto;">
            <div class="required-field-block">
                <h:outputLabel for="email" value="Email-Adresse"></h:outputLabel>
                <h:inputText id="email" label="Email" value="#{loginBean.email}" class="form-control" required="true" requiredMessage="Keine Mailadresse angeben"></h:inputText>
                <h:message for="email" class="text text-danger"></h:message>
            </div>
            <div class="required-field-block">
                <h:outputLabel for="password" value="Passwort"></h:outputLabel>
                <h:inputText id="password" label="Passwort" value="#{loginBean.password}" class="form-control" required="true" requiredMessage="Kein Passwort angegeben"></h:inputText>
                <h:message for="password" class="text text-danger"></h:message>
            </div>
            <h:commandButton  id="sendLogin" update="loginForm" value="Login" type="submit" actionListener="#{loginBean.login}" class="btn btn-primary"></h:commandButton>
            <h:message globalOnly="true"></h:message>
        </h:form>

和我的代码从bean:

    public String login() {
    UserManagement man = new UserManagement();
    try {
        user = man.getUserByEmail(this.email);
    } catch (SQLException | IndexOutOfBoundsException e) {
        String msg = "Login failed";
        addErrorMessage(msg);
        return "loginFailed";
    }
    if(this.user!=null&&this.user.getPassword().equals(password)) {
        this.loggedIn = true;
        return "loginSucceed";
    }
    else {
        String msg = "Unvalid Password";
        addErrorMessage(msg);
        return "loginFailed";
    }
}
private void addErrorMessage(String msg) {
    FacesContext context = FacesContext.getCurrentInstance();
    FacesMessage fm = new FacesMessage(msg);
    context.addMessage(null, fm);
}

我做错了什么?为什么这条信息没有呈现出来?我有点绝望，因为我尝试了所有的ID，但没有任何效果，我很困惑为什么它不起作用。也许这只是一个愚蠢的错误，我一直没有看到:(

Answer 1

h:message组件只呈现来自您必须使用for属性引用的组件的单个消息。

如果你想渲染所有的消息，只需使用h:messages代替:

<h:messages/>