重新显示同一页面时 JSF 2 : ViewScoped Problem, bean 未持久化

Question

我知道为什么，但是当重新显示同一页面时，我的 viewscoped-bean 没有被持久化。我想知道这是否是因为使用了 facelet 模板？

这是我为帮助我解决问题所做的工作:

添加@PostConstruct 方法并从那里进行调试

在 setter 和 getter 方法中添加一些调试

ViewScoped 调试似乎有很多 PostConstruct 方法调用

是的，状态不是持久化的(提交，将标志设置为 true，但是当重新显示标志时再次返回 false)

尝试将范围更改为 session ，在重新启动我的 glassfish 时收到一条错误消息，提示“org.glassfish.deployment.common.DeploymentException:WELD-000072 托管 bean 声明钝化范围必须能够钝化”。必须使我的 bean 可序列化才能跳过此错误。

而在 session 作用域 bean 中，PostConstruct 只被调用一次，并且状态持久化

我想知道我的 ViewScope 案例出了什么问题？

这是我的 facelet 文件:


"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<h:head>
    <title>#{msgs.title}</title>
    <h:outputStylesheet library="css" name="main.css" />
</h:head>
<h:body>
    <ui:composition template="/template/masterlayout.xhtml">
        <ui:define name="windowTitle">Checkbox Lab</ui:define>
        <ui:define name="heading">Checkbox Lab</ui:define>
        <ui:define name="content">
            <h:form>
                <p:messages id="messages" globalOnly="true"/>
                <h:panelGrid columns="3" styleClass="bordered">
                    <h:outputLabel for="Married" value="Married" />
                    <h:selectBooleanCheckbox label="Married" id="Married" 
                         value="#{checkboxLabBean.married}" />
                    <p:message for="Married"/>

                    <p:panel header="debug info" id="debugPanel"
                        toggleable="true" toggleSpeed="300" >
                            <h:panelGrid columns="2">
                            <h:outputText value="rendered :"/> 
                            #{checkboxLabBean.submitted}

                            <h:outputText value="married status :"/> 
                            #{checkboxLabBean.married}
                            </h:panelGrid>
                    </p:panel>
                </h:panelGrid>
                <h:commandButton value="Refresh"
                    action="#{checkboxLabBean.submit}"/>
            </h:form>
        </ui:define>
    </ui:composition>
</h:body>
</html>

这是我的 bean :

package user.ui;

import java.io.Serializable;

import javax.annotation.PostConstruct;
import javax.faces.bean.ViewScoped;
import javax.inject.Named;

@Named
@ViewScoped
public class CheckboxLabBean implements Serializable {
    private boolean married = true;
    private boolean submitted;

    @PostConstruct
    public void debugPostConstruct() {
        System.out.println("Post Construct !");
    }

    public boolean isMarried() {
        return married;
    }
    public void setMarried(boolean married) {
        this.married = married;
    }
    public boolean isSubmitted() {
        System.out.println("returning submit : " + this.submitted);
        return submitted;
    }
    public void setSubmitted(boolean submitted) {
        this.submitted = submitted;
    }

    public String submit() {
        System.out.println("setting submit to true");
        this.submitted = true;
        return null;
    }
}

这是我的 viewscope 和 sessionscope 日志的输出:

View 范围重新启动网络应用程序后首次打开:

[#|2010-12-24T11:01:11.307+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:01:11.310+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:01:11.310+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|returning submit : false|#]

[#|2010-12-24T11:01:11.311+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:01:11.322+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:01:11.322+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=34;_ThreadName=Thread-1;|Post Construct !|#]

View 范围点击刷新按钮后

[#|2010-12-24T11:02:46.129+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.130+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.131+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.131+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.131+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|setting submit to true|#]

[#|2010-12-24T11:02:46.133+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.134+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.134+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|returning submit : false|#]

[#|2010-12-24T11:02:46.134+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.136+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T11:02:46.136+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|Post Construct !|#]

session 范围重新启动网络应用程序后首次打开:

[#|2010-12-24T10:58:54.610+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=32;_ThreadName=Thread-1;|Post Construct !|#]

[#|2010-12-24T10:58:54.612+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=32;_ThreadName=Thread-1;|returning submit : false|#]

session 范围点击刷新按钮后:

[#|2010-12-24T10:59:14.613+0700|INFO|glassfish3.0.1|org.hibernate.validator.engine.resolver.DefaultTraversableResolver|_ThreadID=37;_ThreadName=Thread-1;|Instantiated an instance of org.hibernate.validator.engine.resolver.JPATraversableResolver.|#]

[#|2010-12-24T10:59:14.615+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|setting submit to true|#]

[#|2010-12-24T10:59:14.617+0700|INFO|glassfish3.0.1|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=37;_ThreadName=Thread-1;|returning submit : true|#]

Answer 1

问题似乎是您将 bean 声明为 CDI 托管 bean，不是 JSF 托管 bean 。 @ViewScoped 是 CDI 本身不支持的 JSF 特定范围。

CDI 确实允许您创建自定义范围，因此您可以为其构建支持。事实上，这已经完成了。看到这个:http://seamframework.org/Community/JSF2ViewScopeInCDI

在不使用任何扩展的情况下，以下代码运行良好:

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 "";
    }
}

以及以下 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>

post构造方法现在只会被调用一次，按下命令按钮后页面将刷新但状态将保留。