不接受ManagedBean Params，并且Bean似乎不在范围内 [英] ManagedBean Params not accepted and Bean seemingly not in scope

问题描述

这使用来自以下代码的相同代码 primefaces树控件

This uses the same code that comes from primefaces tree control

@ManagedBean( name = "theName", eager = true)

第一个问题是为什么无法识别名称"和渴望". Eclipse建议我将其中一个参数都更改为值"-因此不确定在那里发生了什么.

The first question is why "name" and "eager" are not recognised. Eclipse suggests I change either parameter to "value" - so not sure whats going on there.

然后，在需要注意的地方大写并创建我的bean

Then, where I have been careful to capitalise where necessary and create my bean

public class TreeBean implements Serializable {

并在我的xhtml中引用它

and reference it in my xhtml

<h:form id="mainForm">  

<p:tree id="treeSingle" value="#{treeBean.root}" var="node"
        selectionMode="single"
        selection="#{treeBean.selectedNode}">

(注意类名的大写).

输出仅显示一个窄条. System.out.println(构造函数为")表明该bean未知.为此，如果我按示例中的代码(顶部提供的链接)按按钮，则会收到错误消息

The output shows only a narrow bar. System.out.println("Constructor called") suggests the bean is not known. To support this, if I press the button as coded in the example (link provided at the top) I get the error

Jan 13, 2014 12:19:26 AM com.sun.faces.context.AjaxExceptionHandlerImpl handlePartialResponseError
SEVERE: javax.el.PropertyNotFoundException: /HelloWorld.xhtml @23,50 selection="#{treeBean.selectedNode}": Target Unreachable, identifier 'treeBean' resolved to null
at com.sun.faces.facelets.el.TagValueExpression.setValue(TagValueExpression.java:133)

关于可能会出现的问题，我现在没有足够的想法了.是否有任何进一步调试的方法，或者任何人对渴望/名称的事情以及导致Bean类成为(我认为)不可见的原因有任何想法.

I've run out of ideas now as to what could be the problem. Is there any way of further debugging this or anyone got any ideas about the eager/name thing and what is causing the Bean class to be (I assume) not to be seen.

先谢谢了. 凯文

推荐答案

beans应该这样定义:

beans should be defined this way:

@ManagedBean(name="treeBean")
@SessionScoped // or whatever scope you would like to use
public class TreeBean implements Serializable {
....

在XHTML中的用法:...="#{treeBean.root}"

Usage in XHTML: ...="#{treeBean.root}"

或

@ManagedBean(name="xyz")
@SessionScoped // or whatever scope you would like to use
public class TreeBean implements Serializable {
....

在XHTML中的用法:...="#{xyz.root}"

Usage in XHTML: ...="#{xyz.root}"

bean名称只是地图的键，您可以随意命名它

bean name is just a key for the map, you can name it whatever you want

bean的范围应来自软件包javax.faces.bean

the scope of the bean should be from the package javax.faces.bean

即对于必须导入的 sessionscoped 豆

import javax.faces.bean.SessionScoped;

以及ManagedBean Annotation

and for the managedBean Annotation

import javax.faces.bean.ManagedBean;

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