Question

我已经将此代码设置为在页面加载期间设置cookie，但它无法正常工作：

标记：

<ui:fragment rendered="#{surveyWebBean.showQuestions}">
    <ui:include src="/general/survey.xhtml" />
</ui:fragment>

代码：

SurveyWebBean.java

@ManagedBean(name = "surveyWebBean")
@SessionScoped
public class EncuestasWebBean extends BaseBean {

    private boolean showQuestions;

    @PostConstruct
    public void init() {
        showQuestions = true;
        UUID uuid = UUID.randomUUID();
        CookieHelper ch = new CookieHelper();
        ch.setCookie("COOKIE_UUID_SURVEY", uuid.toString(), 60 * 60 * 24 * 365 * 10);
    }

    //Getters and Setters
}

CookieHelper.java

public class CookieHelper {

    public void setCookie(String name, String value, int expiry) {

        FacesContext facesContext = FacesContext.getCurrentInstance();
        HttpServletRequest request = (HttpServletRequest) facesContext.getExternalContext().getRequest();
        Cookie cookie = null;
        Cookie[] userCookies = request.getCookies();

        if (userCookies != null && userCookies.length > 0) {
            for (int i = 0; i < userCookies.length; i++) {
                if (userCookies[i].getName().equals(name)) {
                    cookie = userCookies[i];
                    break;
                }
            }
        }

        if (cookie != null) {
            cookie.setValue(value);
        } else {
            cookie = new Cookie(name, value);
            cookie.setPath("/");
        }

        cookie.setMaxAge(expiry);
        HttpServletResponse response = (HttpServletResponse) facesContext.getExternalContext().getResponse();
        response.addCookie(cookie);
    }

    public Cookie getCookie(String name) {

        FacesContext facesContext = FacesContext.getCurrentInstance();
        HttpServletRequest request = (HttpServletRequest) facesContext.getExternalContext().getRequest();
        Cookie cookie = null;
        Cookie[] userCookies = request.getCookies();

        if (userCookies != null && userCookies.length > 0) {
            for (int i = 0; i < userCookies.length; i++) {
                if (userCookies[i].getName().equals(name)) {
                    cookie = userCookies[i];
                    return cookie;
                }
            }
        }
        return null;
    }
}

但是，当我尝试检索Cookie或在Google Chrome检查器或本地数据查看器中检查时，它不会退出

任何想法？

Answer 1

似乎在呈现响应时首次引用bean。您无法在渲染响应阶段设置Cookie。 Cookie在HTTP响应标头中设置。但是目前JSF忙于为响应主体生成一些HTML输出，响应头很可能已经发送了很长时间。

您需要在第一位写入响应正文之前设置Cookie 。

您可以使用<f:event type="preRenderView">在渲染响应实际开始之前调用bean侦听器方法。

<f:event type="preRenderView" listener="#{surveyWebBean.init}" />

public void init() { // (remove @PostConstruct!) if (showQuestions) { return; // Already initialized during a previous request in same session. } showQuestions = true; UUID uuid = UUID.randomUUID(); CookieHelper ch = new CookieHelper(); ch.setCookie("COOKIE_UUID_SURVEY", uuid.toString(), 60 * 60 * 24 * 365 * 10); }

无关具体问题，对于CookieHelper，也许您在基于JSF 1.x的资源中找到它们，但您需要知道，因为JSF 2.0有新的cookie ExternalContext上的相关方法，例如getRequestCookieMap()，可以简化获取cookie的过程。 JSF实用程序库Faces的OmniFaces实用程序类也有一些与cookie相关的方法。

Faces.addResponseCookie("cookieName", cookieValue, "/", 60 * 60 * 24 * 365 * 10);

String cookieValue = Faces.getRequestCookie("cookieName");

无法在PostConstruct上设置cookie

1 个答案: