以“is"开头的布尔属性不工作 [英] boolean properties starting with "is" does not work

问题描述

我有一个使用 JSF 2.1 和 PrimeFaces 的项目.我尝试使用一个简单的 <h:outputText> 引用 #{myBean.matriz} 并收到此错误:

I have a project that use JSF 2.1 and PrimeFaces. I tried to use a simple <h:outputText> referencing #{myBean.matriz} and I got this error:

SEVERE: javax.el.PropertyNotFoundException: ... value="#{myBean.matriz}": Missing Resource in EL implementation: ???propertyNotReadable???

getter 是:isMatriz().应该是 getMatriz() 吗?

The getter is: isMatriz(). Should it be getMatriz()?

推荐答案

is 前缀仅适用于 boolean，不适用于 Boolean.

The is prefix works only for boolean, not Boolean.

您显然实际上有一个 Boolean 属性.

You've there apparently actually a Boolean property.

您有 2 个选项来修复它:

You've 2 options to fix it:

1. 使用 get 前缀重命名 getter.
2. 将 Boolean 替换为 boolean.请注意，它将默认为 false 而不是 null.

1. Rename the getter with get prefix.
2. Replace Boolean by boolean. Note that it will default to false instead of null.

另见:

• JavaBeans 规范 - 第 8.3.2 章
• Java 如何表达式语言解析布尔属性?(在 JSF 1.2 中)

See also:

• JavaBeans specification - chapter 8.3.2
• How does Java expression language resolve boolean attributes? (in JSF 1.2)

与具体问题无关，类路径对于 EL 实现来说似乎是一团糟.消息 Missing Resource in EL implementation: ???propertyNotReadable??? 表明 EL impl 无法在自己的 JAR 中找到相关的错误消息，应该如下所示

Unrelated to the concrete problem, the classpath seems to be a mess as to EL implementation. The message Missing Resource in EL implementation: ???propertyNotReadable??? indicates that the EL impl wasn't able to find the associated error message in own JAR which should look like this

Property 'matriz' not found on type com.example.MyBean

确保您没有在 /WEB-INF/lib 中任意下载 EL JAR 文件.摆脱他们.servletcontainer 已经提供了自己的.

Make sure that you don't have arbitrarily downloaded EL JAR files in /WEB-INF/lib. Get rid of them. The servletcontainer already provides its own.

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