jsf - doesn't navigate when actionListener =“#{bean.method}” is declared

Question

我正在尝试创建一个页面，该页面允许用户登录系统然后导航到主页。我已经设法让它做一个或另一个，但无法弄清楚如何让它做两个。我已经爬过所有网站，但找不到合适的答案。请帮忙。我的代码如下:
XHTML:

<h:form>
    <p:growl id="growl" showDetail="true" life="3000" />
    <h:panelGrid columns="2" cellpadding="5">
        <h:outputLabel for="username" value="Username: " />
        <p:inputText value="#{login.username}" id="username" required="true"
            label="username" />
        <h:outputLabel for="password" value="Password: " />
        <h:inputSecret value="#{login.password}" id="password" required="true"
            label="password" />
        <p:commandButton ajax="false" id="loginButton" value="Login"
            update="growl" actionListener="#{login.login}" />
    </h:panelGrid>
</h:form>

Java类:

@ViewScoped
@ManagedBean
@SessionScoped
public class Login implements Serializable
{
private static final long serialVersionUID = 1L;
private String username;
private String password;

public String login(ActionEvent actionEvent)
{
    RequestContext context = RequestContext.getCurrentInstance();
    FacesMessage msg = null;
    boolean loggedIn = false;

    if(username != null && username.equals("admin") && password != null && password.equals("admin"))
        {
            loggedIn = true;
            msg = new FacesMessage(FacesMessage.SEVERITY_INFO, "Welcome", username);
        }
    else
    {
        loggedIn = false;
        msg = new FacesMessage(FacesMessage.SEVERITY_WARN, "Login Error", "Invalid Credentials");
    }
    FacesContext.getCurrentInstance().addMessage(null, msg);
    context.addCallbackParam("loggedIn", loggedIn);

    FacesContext context2 = FacesContext.getCurrentInstance();
    context2.getExternalContext().getFlash().setKeepMessages(true);

    return "ProEJT?faces-redirect=true";
}

这里要求的是我的 faces-config.xml:

<faces-config xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-facesconfig_2_0.xsd"
version="2.0">
<navigation-rule>
    <from-view-id>/login.xhtml</from-view-id>
    <navigation-case>
        <from-action>#{login.login}</from-action>
        <from-outcome>loggedin</from-outcome>
        <to-view-id>/ProEJT.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

当我尝试这样做时，我将登录方法的返回值更改为“登录”。

提前感谢您的任何帮助!!

Answer 1

Action 监听器不应该做业务逻辑和导航。他们应该监听 Action 事件。业务逻辑和导航应该以真正的操作方法完成。
代替

<p:commandButton ... actionListener="#{login.login}" />

public String login(ActionEvent actionEvent) {}

经过

<p:commandButton ... action="#{login.login}" />

public String login() {}

一切都应该很好。
也可以看看:

Differences between action and actionListener