JSF 2 : ViewScoped Problem, bean not persisted when redisplaying the same page

前端未结

关注

 3  1931

Im sure why, but my viewscoped-bean doesnt get persisted when redisplaying the same page. Im wondering if this is because of the use of facelet templates ?

Here\'s w

相关标签:

3条回答

[愿得一人]

2021-01-06 12:36

The problem seems to be that you are declaring your bean to be a CDI managed bean, not a JSF managed bean. @ViewScoped is a JSF specific scope that is not natively supported by CDI.

CDI does allow you to create custom scopes, so you can build support for it. In fact, this has already been done. See this: http://seamframework.org/Community/JSF2ViewScopeInCDI

Without using any extensions, the following code works perfectly well:

import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;

@ManagedBean
@ViewScoped
public class MyBean {

    String state = "";

    @PostConstruct
    public void test() {
        System.out.println("pc called");
        state = "state set";
    }

    public String getState() {
        return state;
    }

    public String action() {
        return "";
    }
}

And the following Facelet:

<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core">
    <h:body>

        #{myBean.state}

        <h:form>
            <h:commandButton value="test" action="#{myBean.action}"/>
        </h:form>
    </h:body>
</html>

The post construct method will only be called once now, and after you press the command button the page will refreshed but the state will be retained.

0 讨论(0)

滥情空心

2021-01-06 12:47

Seam Faces 3 provides a @ViewScoped annotation for CDI beans, along with a ton of other features to bridge the gap between CDI and JSF.

0 讨论(0)
发布评论:

提交评论
- 加载中...
挽巷

2021-01-06 12:50

Based on advice posted here, I have started using MyFaces CODI to solve this problem. I can't tell you if Seam or CODI is better, but at least it lets me move past trying to puzzle out scopes and get on with coding the application.

0 讨论(0)
发布评论:

提交评论
- 加载中...